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10/15/2023
Does Eating Late at Night Really Make You Fat?
Contents
- Recent findings on the association between late night eating and weight gain
- Are late night meals really fattening? (My thoughts)
- It is impossible to explain weight gain with BMAL1.
- Conclusion
In Japan, many people (especially women) tend to avoid eating dinner, or dessert or sweets late at night (after nine p.m.) because they do not want to gain weight.
But does that really make sense? Actually, some people say that they have started eating dinner late at night and gained more weight than before, but I believe that is a misconception.
1. Recent findings on the association between late night eating and weight gain
(1) A cross-sectional study examining 17-year changes in energy and macronutrient intake across eating occasions in the 1946 British birth cohort, reported a greater proportion of energy towards the latter half of the day, and as a population, there has been a shift in the timing of when we eat[1].
In a cohort study of 1,245 non-obese, non-diabetic middle-aged adults, participants who consumed 48% or more of their daily energy intake at dinner were twice as likely to be obese at a six-year follow-up, even after adjusting for variations in energy intake, physical activity, and BMI, etc. at baseline[2].
(2) An increased propensity for weight gain is observed in those with eating occasions extending into the night hours, when the body is usually primed for rest, such as night shift workers and shift workers[3].
A meta-analysis published in 2018 reviewed 28 studies and found that shift workers had a higher frequency of developing abdominal obesity than other obesity types.
Permanent night workers demonstrated a 29% higher risk of obesity/being overweight than rotating shift workers[4].
(3) Previous observational studies in humans have linked late eating with higher obesity risk and lower success rates of dietary and surgical weight loss that could not be explained by differences in reported caloric intake or physical activity. It has been suggested that meal timing itself might influence body weight independent of changes in energy intake and activity-related energy expenditure[5].
(4) A systematic review published in 2017 investigated the relationship between evening energy intake and BMI. Of the 121 relevant articles, ten observational studies and eight clinical trials were included in the systematic review (a total of 102 texts did not meet the review eligibility criteria).
Four of the observational studies showed a positive association with BMI, five showed no association, and one indicated a weak, inverse relationship. The meta-analysis of observational studies showed only a slight trend between greater BMI and greater evening energy intake.
The majority of clinical trials reported that a smaller evening meal produced greater weight loss; however, the meta-analysis showed no significant difference between groups.
(Of note, there is considerable inconsistency in the definition of meal timing, quantification of energy intake, and methods of dietary assessment, suggesting that the heterogeneity of the included studies may have affected the reliability of the study results.)[6]
(5) In a randomized controlled crossover trial published in 2022, sixteen overweight or obese subjects completed two laboratory protocols: one with a strictly controlled early meal schedule, and the other with the exact same meals, each scheduled about four hours later in the day.
The results showed that late eating increased hunger, decreased energy expenditure, and affected molecular pathways in adipose tissue.
This study aimed to investigate the direct effect of meal timing, so other effects were isolated by controlling for confounding variables such as caloric intake, physical activity, sleep, and light exposure. But in real life, many of these factors may themselves be influenced by meal timing[7].
2. Are late night meals really fattening? (My thoughts)
If protein and fat synthesis is stimulated more when sleeping, by hormones and other factors, it is not surprising that, in a sense, everyone is somewhat more likely to gain weight at night than in the morning or afternoon. That further complicates the issue. However, I don’t think It is always correct to associate night time eating with an increased risk of obesity.
As I mention in the following article, I believe that "meal timing" is not the only important factor in the increased risk of obesity, "what you eat" has to be included. Eating late at night and skipping breakfast are two sides of the same coin, and that such eating habits, when combined with an unbalanced diet, can easily lead to intestinal starvation, making people more likely to gain weight over time. I would like to explain the following four patterns.
[Related article] "When to Eat" Is Important, but It Should Be Paired With "What to Eat"
(1) When each meal is four hours late
As shown in section 1, a short-term intervention trial in 2022 showed that meals scheduled four hours later compared to early meal schedule affects appetite, energy expenditure, and molecular pathways in adipose tissue, but it remains unclear whether it makes people obese in the long run.
I used to work as a cook at a Japanese restaurant, and this is how I timed my meals. I ate a light breakfast around nine a.m., and lunch was served around three p.m. Dinner was after eleven p.m., when the restaurant was closed, but I have seen a few acquaintances who have put on weight because of this.
The typical cooks or employees working in restaurants also generally delay their meals by three to four hours, but if they eat a balanced meal at breakfast and lunch, and the meal intervals are consistent, it is unlikely－at least in Japan－that this will significantly increase their risk of obesity.
Of course, some people do gain weight over time or suddenly, but I believe that it is "what they eat" that matters. If they continue their eating habits, such as eating unbalanced meals leaning toward easily digestible carbohydrates and skipping breakfast, they will be more likely to gain weight over the long haul.
If researchers wanted to investigate whether slim people actually gain weight by continuing this pattern of eating, they could find out by asking restaurant staff to cooperate and having them eat the same meal menu three times a day (breakfast, lunch, and dinner).
(2) Longer intervals between lunch and dinner
I believe that the typical pattern when late eating causes weight gain is that lunch is consumed around noon, and dinner is delayed until around eight or nine p.m.
A friend of mine works in sales for his company. He travels by a car, and he says he usually eats his dinner around eight or nine p.m. He used to be slender, but after he got married, he had less pocket money at his disposal, and sometimes he had to eat simple meals such as ramen/udon noodles or a Japanese beef/chicken rice bowl, etc. for lunch.
He had gained more than ten kilos during the previous two years, but I believe this is more of a problem of having simple lunches skewed toward carbohydrates and putting up with hunger for longer periods of time, rather than having a late dinner.
This is the same as the inverted triangle-type diet described in the breakfast article, in which breakfast and lunch are light, and dinner makes up for the missing nutrients and calories.
In that case, intestinal starvation is more likely to be induced before a late dinner, and the set-point weight may unknowingly go up.
(3)Snacking before bed and skipping breakfast
Also, some people may snack or eat a light meal after dinner but before bed , but perhaps those people are prone to skipping breakfast.
As shown in the quote in section [1], there are observational studies showing that "eating at night increases the risk of weight gain over time," but in my opinion, late eating can also be related to skipping breakfast (having two meals a day) or eating light meals during the day.
If people skip breakfast, and night time meals and lunches are unbalanced leaning toward easily digestible carbohydrates and some protein, with a lack of vegetables, they are more likely to induce intestinal starvation little by little over time.
Conversely, if you consume a well-balanced meal including fibrous vegetables, dairy products, protein, and fat, etc., at an earlier time of the day, you can prevent intestinal starvation because undigested foods will remain in the intestines for a longer period of time.
(4) Night time snacking may not cause weight gain
If people eat regular, well-balanced meals three times a day, every day, then for many of them, I believe eating before bed does not cause much weight gain.
As I mention throughout this blog, if a person who normally moderates their caloric intake eats sweets or ramen noodles late at night, they may gain a few kilograms, but it means their present weight goes back to their set-point weight.
Actually, there are many thin people in Japan, but even if they eat sweets or a light meal before bedtime in addition to their three meals in order to gain weight, it is more likely that they will not gain weight. In fact, I suppose that some of them may even lose weight if they do not have a strong digestive ability (at least for me, this is one hundred percent true).
The reason being that, by nature, it is good to rest your body and your stomach while you sleep, but if you eat before going to bed, your gastrointestinal tract has to continue to work throughout the night (diet-induced thermogenesis).
I suspect that this may be burdensome and result in a decrease in both cellular regeneration and synthesis of protein and lipids.
3. It is impossible to explain weight gain with BMAL1
In Japan, some experts explain as if the secretion volume of BMAL1 (Brain and Muscle Arnt-like protein-1 ) and weight gain are correlated. BMAL1 is a protein involved in the biological clock, and is said to be related to adipogenesis.
Its secretion begins to increase around six p.m. and peaks between ten p.m. and two a.m., which seems to be thought of as a rationale behind the fact that people are several times more likely to gain weight if they eat late at night (e.g. ten p.m.) than eating at six p.m. for the same number of calories.
However, I think that explanation is a bit of a stretch. The reason is that the "digestion time" is missing. For example, if they eat a meal at ten p.m., it will take four to six hours for it to be digested and absorbed, depending on the person and how foods are combined, etc. Fats/oils are particularly indigestible, so they may find that even in the morning after seven to eight hours, their food is still undigested and their stomach is upset.
In other words, the time for digestion and absorption is not taken into account, so there is no way to correlate the meal time with the BMAL1 value.
The reason why BMAL1 peaks between ten p.m. and two a.m. is that if we humans have been eating dinner around six p.m. since ancient times, I suspect that BMAL1 levels are also higher so that lipids can be successfully synthesized just as the food is digested and absorbed, and nutrition is transported to all cells in the body.
4. Conclusion
Hormones and other secretions are closely related to circadian rhythms, which differ significantly from day to night. The fact that many other factors come into play further complicates the issue of late night eating and the increased risk of obesity.
However, I believe that the root cause of obesity is due to a higher set-point weight, and here is how "late night eating" can increase one’s set-point for body weight (see Figure-1, B).
（Figure-1）
(1) The phrase "gaining weight" has two meanings. A person who normally moderates their caloric intake in order to lose weight may gain a few kilos overnight if they eat more calories than necessary.
However, this is the case going back to their set-point weight (see Figure-1, A) and should not be confused.
In this case, it should not matter whether the dinner is consumed at seven p.m. or ten p.m.
(2) For a thin or medium-sized person who eats three times a day regularly in a well-balanced manner, I don’t think that additional snacks or light meals before bed are the reason for weight gain and an increased risk of obesity.
Even in the eating patterns where each meal (breakfast, lunch, and dinner) is eaten four hours later than usual as seen in restaurant workers, if they eat a well-balanced diet every day, it is unlikely that this will significantly increase their risk of obesity.
In other words, while an increased feeling of hunger due to eating later than normal may accelerate the onset of intestinal starvation, intestinal starvation is unlikely to occur when there is still plenty of undigested food in the gut.
(3)As in the 2017 review cited in section 1-(4) above, the "relationship between evening energy intake and weight gain (BMI)" could well produce different results depending on the population being studied. This is because late night eating may not lead to weight gain in those who eat a balanced breakfast and lunch (e.g. morning chronotypes).
(4)On the contrary, people who eat late at night may have a habit of skipping breakfast or eating light meals during the day.
If a person eats a well-balanced meal from diverse food groups at breakfast－the first meal of the day when the gastrointestinal tract starts working－, undigested food tends to remain in the intestines for a longer period of time, but they do not eat breakfast, so lunch is their first meal.
If lunch is unbalanced leaning toward easily digestible carbohydrates and some protein, and that dinner is around at eight or nine p.m., people feel hungrier and intestinal starvation is more likely to be induced. These eating patterns are prone to increasing one’s set-point weight in the long run and making people gain weight.
In other words, just because you eat late at night, it does not necessarily lead to obesity. The main problem, in my opinion, is rather unbalanced meals and “prolonged feelings of hunger” over a twenty-four hour period.
(5)If you have to eat dinner late at night, you can snack on milk, sandwiches, nuts, etc. around five p.m. and spread out the meal in order to prevent intestinal starvation. Even if you do not have enough time for breakfast, I think it is important to at least drink milk or café au lait.
(6) In the real world, it is even more difficult to eat a well-balanced meal when trying to eat late at night. In Japan, around eleven p.m., people may end up eating curry, a beef bowl, or ramen noodles from chain restaurants, or a lunch box from a convenience store.
It may be especially difficult for night shift workers to secure well-balanced meals, and I think it may be necessary to conduct observational research focusing on balance from a variety of foods including vegetable intake rather than caloric content.
<References>
[1]Almoosawi S et al. Daily profiles of energy and nutrient intakes: are eating profiles changing over time?. Eur J Clin Nutr 66, 678–686 (2012). https://doi.org/10.1038/ejcn.2011.210
[2]Bo S et al. Consuming more of daily caloric intake at dinner predisposes to obesity. A 6-year population-based prospective cohort study. PLoS One. 2014 Sep 24;9(9):e108467. doi: 10.1371/journal.pone.0108467. PMID: 25250617; PMCID: PMC4177396.
[3]Davis R et al. The Impact of Meal Timing on Risk of Weight Gain and Development of Obesity: a Review of the Current Evidence and Opportunities for Dietary Intervention. Curr Diab Rep. 2022 Apr;22(4):147-155. doi: 10.1007/s11892-022-01457-0. Epub 2022 Apr 11. PMID: 35403984; PMCID: PMC9010393.
[4]Sun M et al. Meta-analysis on shift work and risks of specific obesity types. Obes Rev. 2018 Jan;19(1):28-40. doi: 10.1111/obr.12621. Epub 2017 Oct 4. PMID: 28975706.
[5][7] Vujović N et al. Late isocaloric eating increases hunger, decreases energy expenditure, and modifies metabolic pathways in adults with overweight and obesity. Cell Metab. 2022 Oct 4;34(10):1486-1498.e7. doi: 10.1016/j.cmet.2022.09.007. PMID: 36198293; PMCID: PMC10184753.
[6]Fong M et al. Are large dinners associated with excess weight, and does eating a smaller dinner achieve greater weight loss? A systematic review and meta-analysis. British Journal of Nutrition. 2017;118(8):616-628. doi:10.1017/S0007114517002550
09/09/2023
The Reason Why a Well-Balanced Breakfast Helps to Prevent Weight Gain
Contents
- A background of the importance of breakfast in recent years
- How eating breakfast affects weight management? My thoughts
(1) A well-balanced breakfast can help prevent gaining weight
(2) Skipping breakfast makes it easier to gain weight
(3) Lightening your breakfast and lunch makes you more likely to gain weight - Conclusion
In the previous article, I introduced the concepts of a "biological clock," and “chrono-nutrition,” but if you have not read them yet, please read the following article first.
This time, I am going to state my own thoughts on how eating breakfast affects weight management concretely by my intestinal starvation theory.
[Related article]
"When to Eat" Is Important, but It Should Be Paired With "What to Eat"
1. A background of the importance of breakfast in recent years
(1) Observational evidence suggests that there is an association of breakfast eaters with lower body weight (lower BMI) compared to non-breakfast eaters.
However, there is little causal evidence to support this conjecture. Regular breakfast intake is associated with health-promoting behaviors, implying that breakfast intake may be a proxy for health-promoting behaviors. The association in observational studies may reflect a "healthy user bias."[1]
(2) Short-term studies highlight physiological mechanisms by which breakfast may affect body weight, such as appetite, energy expenditure (metabolism), and fat oxidation. However, whether the proposed physiological mechanisms translate to a long-term effect on energy intake and body weight remains unclear[2].
(3) Some hypotheses with regard to breakfast intake and lower body weight speculate that breakfast intake is important for regulating subsequent energy intake. Some studies have shown that skipping breakfast results in higher energy intake at lunch. On the other hand, others suggest that skipping breakfast may not compensate for a need for increased energy intake later in the day, resulting in a decrease in total daily caloric intake relative to when breakfast is consumed[3].
(4) Public health authorities commonly recommend breakfast intake to reduce obesity.
A randomized controlled trial (RCT) in the U.S. in 2014 tested the effectiveness of a recommendation to eat or skip breakfast on weight loss. Approximately 300 overweight or obese adults who trying to lose weight were randomly assigned to one of three groups (control, breakfast, or no breakfast), and the effect of treatment assignment on weight loss was tested in a free-living setting for 16 weeks.
However, this trial showed no effect of a recommendation to eat or skip breakfast on weight loss[4]. In this RCT, the total daily caloric intake, which foods to combine at breakfast, and the timing of meals, etc. were considered free and not specified.
(5) A review of the scientific literature up to 2006 on the "relationship between breakfast habits and body weight and chronic disease risk," analyzed through a MedLine search, pointed to the following issues: Many observational studies have found that breakfast frequency is inversely associated with obesity and chronic disease, but observational studies have some limitations. Only four relatively small, short-term randomized trials have examined breakfast intake and body weight or chronic disease risk, with mixed results.
Measurement of breakfast frequency for the most part is self-reported and subject to each individual's idea of what constitutes breakfast. Therefore, it is possible that the luck of a universal definition for breakfast and measurement of the breakfast has led to conflicting results in some cross-sectional and prospective studies assessing the association between breakfast and obesity and chronic disease risk [5].
2. How eating breakfast affects weight management? My thoughts
I think the concept of “chrono-nutrition” is very important in this day and age, but there are many aspects that cannot be explained by metabolism or hormones alone.
Based on the conventional belief that obesity is caused by "overeating and/or lack of exercise," it does not make sense that people who eat breakfast are associated with lower body weight despite consuming more calories per day than those who skip breakfast. So many researchers have tried to explain the long-term effects of breakfast consumption on body weight by examining the changes in energy expenditure over time when breakfast is consumed or skipped. However, I believe this theory has its limitations.
I think it makes more sense to explain this with my intestinal starvation theory.
As I have mentioned, the phrase "gaining weight" has two meanings, and whether or not breakfast is consumed has a lot to do with the conditions under which intestinal starvation is induced, and it can affect body weight over times in the sense that it can alter one’s set-point weight.
(1) A well-balanced breakfast can help prevent gaining weight
Breakfast is the start of the day, and when you eat breakfast, your resting gastrointestinal tract becomes active.
If you eat a variety of food at that breakfast, such as dairy products, fibrous vegetables, seaweed, legumes, and protein, you can prevent intestinal starvation because undigested food will remain in your intestines for around ten hours or so (this is because our intestines are seven to eight meters long).
Also, if you eat well both at lunch and dinner, you are less likely to gain weight (meaning that your set-point weight does not go up), since there is some undigested food remaining over a twenty-four-hour period in your gastrointestinal tract.
(Typical Japanese breakfast we used to have)
This is the reason why people who are originally slim or medium-sized and have this kind of lifestyle are unlikely to change their body shape throughout their lives, even if they eat without worrying about calories.
However, keep in mind that those who are already overweight will not necessarily lose weight just by eating breakfast (since their set-point weight is already high).
(2) Skipping breakfast makes it easier to gain weight
People who do not eat breakfast may be associated with a nocturnal lifestyle (late night dinner or eating light meals before bed). In short, the main reason for them skipping breakfast may be a lack of appetite or a lack of time to eat.
Not everyone will gain weight if they skip breakfast, but based on my theory, if some conditions are met and overlapped, it makes one more likely to gain weight in the sense that one’s set-point weight increases. If you eat only two meals a day, the interval between meals is longer, so simply what you eat for lunch and dinner has a big impact on the induction of intestinal starvation.
For instance, if you finish dinner at ten p.m., you will not eat for almost fourteen hours until the next day, at noon. Skipping breakfast makes you hungry, so in Japan, people tend to eat lunch with many carbohydrates (rice or noodles) and some meat. Some of them are satisfied with just being full, and their meal may lack fiber and other nutrients.
However, since they have not eaten breakfast, all they have in their gut is that meal at lunch.
If they repeatedly follow a pattern of not eating until eight or nine p.m. in that state, they are likely to induce intestinal starvation little by little, and their set-point weight may go up over time.
Some experts also point out that skipping breakfast and eating a carbohydrate-dense meal when hungry can cause blood glucose levels to spike, leading to high insulin secretion.
This may be true, but in any case, the combination of a "prolonged feeling of hunger" and an unbalanced diet high in carbohydrates and with a lack of vegetables, is likely to increase the risk of obesity and dysglycemia.
You can prevent intestinal starvation by doing the following: if you don't have time to eat in the morning, at least drink some milk, and eat a balanced lunch and dinner with a smaller amount of carbohydrates. And if you have to eat dinner late, eat something such as chocolate or nuts, even around five p.m.
(3) Lightening your breakfast and lunch makes you more likely to gain weight
On the other hand, breakfast can be fattening (in the sense that it increases one's set-point weight) even if one eats it. It is a so-called inverted triangle-type diet, in which breakfast and lunch are light (one might even skip lunch) and dinner makes up for the missing nutrients and calories.
For example, if you just have a light breakfast (a piece of bread, coffee, mashed potatoes, and ham) in the morning, and a rice ball, hamburger, or instant noodles, etc. for lunch, it is easy to induce a intestinal starvation state before dinner, contrary to the situation described in (1) above.
When the gastrointestinal tract becomes active after breakfast, you usually go to the bathroom, and when you do, the only food left in your stomach is what was eaten at breakfast (in this case, mainly carbohydrates and easily digestible protein).
If lunch is also a simple carbohydrate-based meal and lacks fiber and other nutrients, all the food in the intestines will be digested by dinner, which makes it easier to develop a state of intestinal starvation.
In short, if breakfast is well-balanced with choices from the various food groups, you are less likely to gain weight, but if it is a simple and unbalanced one, there is a good chance you will gain weight over the long haul.
Therefore, it is not only a recommendation to eat breakfast, but also to eat a well-balanced one that includes fibrous vegetables, protein, and dairy products, etc.
3. Conclusion
I think what has confused researchers over the years is “whether or not breakfast itself is directly associated with reduced risk of obesity and chronic disease? In other words, is there a causal link there?," and my thoughts, based on the intestinal starvation theory, are as follows:
(1)First, I think it is quite possible that people who usually eat breakfast have other healthy lifestyle habits.
For example, they may eat three times a day regularly, with a well-balanced diet that includes vegetables, dairy products, and protein, etc. throughout the day. They may also exercise religiously, get good quality sleep, and live in accordance with their circadian rhythms.
On the other hand, those who tend to skip breakfast may have a nocturnal lifestyle and poor habits in terms of drinking, smoking, sleeping, and dietary balance.
In short, there might be some confounding factors associated with breakfast.
(2)However, as explained in section [2] above, eating a well-balanced breakfast early in the morning, will prevent intestinal starvation being induced by allowing undigested food in the gastrointestinal tract to remain around ten hours or so. Other health benefits of having undigested food such as fiber and fat in the gut, would include reducing blood sugar spikes and regulating appetite.
On the other hand, an unbalanced breakfast skewed towards easily digestible carbohydrates, proteins, and processed foods, etc. can lead to weight gain, so I do not believe that "breakfast" itself has the effect of deterring weight gain. I’m certain that it is "which foods to combine" at breakfast that matter.
I personally think that if you don't want to eat breakfast, that's fine, but isn't it important to eat lunch and dinner in a balanced manner with a moderate amount of carbohydrates to maintain good health and reduce the risk of obesity?
(3)In my theory, the problem of obesity implies a higher set-point weight, and I believe just eating breakfast does not necessarily lower the set-point weight of a person who is already overweight.
In other words, even if a randomized intervention to "eat or skip breakfast" was conducted in obese or overweight people as in a 2014 U.S. randomized controlled trial (RCT) shown in section [1] above, it may be difficult to demonstrate the benefits of breakfast.
But, this does not mean that breakfast itself is meaningless.
References：
[1]Flanagan A, et al. Chrono-nutrition: From molecular and neuronal mechanisms to human epidemiology and timed feeding patterns. J Neurochem. 2021 Apr;157(1):53-72. doi: 10.1111/jnc.15246. Epub 2020 Dec 10. PMID: 33222161.
[2][3][4]Dhurandhar EJ et al. The effectiveness of breakfast recommendations on weight loss: a randomized controlled trial. Am J Clin Nutr. 2014 Aug;100(2):507-13. doi: 10.3945/ajcn.114.089573. Epub 2014 Jun 4. PMID: 24898236; PMCID: PMC4095657.
[5]Timlin MT, Pereira MA. Breakfast frequency and quality in the etiology of adult obesity and chronic diseases. Nutr Rev. 2007 Jun;65(6 Pt 1):268-81. doi: 10.1301/nr.2007.jun.268-281. PMID: 17605303.
09/08/2023
"When to Eat" Is Important, but It Should Be Paired With "What to Eat"
Contents
- What is chrono-nutrition?
- The importance of meal timing in the recent surge in obesity
- My thoughts
Chrono-nutrition has become increasingly important in recent years, and I have provided a brief background on this topic. At the end of this article, I would like to explain how my intestinal starvation theory relate to “when to eat.”
1. What is chrono-nutrition?
・Living organisms on the earth synchronize their activity to a 24-hour light and dark cycle generated by the rotation of the earth. This biological rhythm is called the circadian rhythm, which means “approximately one day.” Biological clocks are organisms’ natural timing devices, regulating the cycle of circadian rhythms. Recent studies have shown that clock genes such as BMAL1, CLOCK, PERs, and CRYs play central roles in the oscillation of the circadian rhythm[1].
・The circadian clock can be divided into two parts: the master clock, located in the suprachiasmatic nucleus (SCN) of the hypothalamus, which receives light cues, and the peripheral clocks that reside in organs and tissues throughout the body.
External stimuli (time cues) such as the light-dark cycle and the timing of food intake provide daily signals for entrainment (time-setting) of the master clock, and of metabolic rhythms in peripheral tissues, respectively[2].
Peripheral clocks are highly responsive to food intake in addition to the entrainment (synchronizing action) from the master clock.
・‘Chrono-nutrition’ is the study of the interaction between biological rhythms and nutrition, and the relationship between these factors and human health. Chrono-nutrition encompasses distribution of energy, frequency and regularity of meals, duration of the eating period, and the relative importance of these factors on metabolic health and risk of chronic disease. A growing body of evidence in human studies indicates that the timing of food intake throughout the day can have a significant impact on metabolic health and general well-being[3].
In Japan, it is generally believed that in addition to "what and how much" you eat, "when and how” you eat is considered important for maintaining metabolic health.
2. The importance of meal timing in the recent surge in obesity
(1)“What and when we eat” has changed dramatically in modern society.
Mistimed food intake in connection with the day/night cycle, such as skipping breakfast or eating later in the day, can disrupt circadian rhythms, which has been hypothesized to contribute to the development of obesity and associated cardiometabolic disorders[4].
(2) There is a 3.5-year follow-up study showing that consuming a larger proportion of energy earlier in the day or at lunch, appeared to reduce the risk of weight gain[5].
On the other hand, previous observational studies in humans, have linked late eating with a higher risk of obesity and impaired dietary weight loss success that could not be explained by differences in reported caloric intake or physical activity [6].
(3) A short-term study (randomized controlled crossover trial) published in 2022 reported that late eating increases hunger, decreases metabolism, and alters molecular pathways involved in lipid metabolism[7], but it remains unproven whether it makes people obese in the long run.
(4) Previous observational studies suggest that meal timing itself might influence body weight, independent of changes in energy intake and activity-related energy expenditure[8].
The mechanism behind the observed increased risk of obesity and weight gain in shift workers and in populations frequently eating late at night is likely to be multifaceted, and it cannot be explained by disrupted energy intake alone[9].
3. My thoughts
While “total daily caloric intake” is still being emphasized, I think it is a step forward that people are beginning to understand the importance of "when to eat,” even if it is the same caloric intake. And it has been my own experience that incorrect meal timing disrupts my biological rhythms, and I have no doubt that the discovery of clock genes will continue to increase the importance of this field.
In fact, my intestinal starvation theory is related to "circadian rhythms" and "chrono-nutrition.” This is because the gastrointestinal tract gets active when food is consumed. I believe my theory also explains why a well-balanced breakfast and regular eating habits can prevent weight gain, and why irregular lifestyles lead to an increased risk of obesity.
As quoted in section 2 above, some observational studies suggest that "mistimed food intake such as eating later in the day is linked to a higher risk of obesity that cannot be explained by disruption of caloric intake alone." But as I have explained throughout this blog, I don’t believe that obesity itself is directly related to the amount of calories consumed or burned.
An unbalanced diet skewed toward easily digestible refined carbohydrates, protein, and processed foods is more likely to cause intestinal starvation when combined with irregular meal timing. This typical meal timing pattern is represented by skipping breakfast or eating late at night.
If obesity cannot be easily treated by returning to eating at regular times during the day, it means that one's set-point for body weight has increased.
[Related article]
In other words, "when to eat" is important, but "what and how to eat" is important as well, and I believe they must always be considered as a set. If we focus only on caloric intake, we may forget the importance of traditional eating styles and dietary balance. (Note: Some Japanese nutritionists often stress how important the traditional Japanese diet is in addition to "what, when, and how you eat” for maintaining good health, and I totally agree with them on that point.)
In the category of "chrono-nutrition," I'll break it down into four articles on (1) breakfast, (2) late dinners, (3) frequency of eating, and (4) irregular meals, and explain in more detail how they relate to my intestinal starvation theory.
[Related article]
The Reason Why a Well-Balanced Breakfast Helps to Prevent Weight Gain
References：
[1]”What is a circadian rhythm?”, MEDICAL ＆ BIOLOGICAL LABORATORIES CO., LTD.
[2] [3]Flanagan A et al., Chrono-nutrition: From molecular and neuronal mechanisms to human epidemiology and timed feeding patterns. J Neurochem. 2021 Apr;157(1):53-72. doi: 10.1111/jnc.15246. Epub 2020 Dec 10. PMID: 33222161.
[4] [5][9]Davis R et al., The Impact of Meal Timing on Risk of Weight Gain and Development of Obesity: a Review of the Current Evidence and Opportunities for Dietary Intervention. Curr Diab Rep. 2022 Apr;22(4):147-155. doi: 10.1007/s11892-022-01457-0. Epub 2022 Apr 11. PMID: 35403984; PMCID: PMC9010393.
[6][7][8] Vujović N et al., Late isocaloric eating increases hunger, decreases energy expenditure, and modifies metabolic pathways in adults with overweight and obesity. Cell Metab. 2022 Oct 4;34(10):1486-1498.e7. doi: 10.1016/j.cmet.2022.09.007. PMID: 36198293; PMCID: PMC10184753.
02/17/2023
Calorie Calculation: Why the Atwater Coefficient Is Not Perfect
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Contents
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- What is the Atwater coefficient in the first place?
- Digestion is an entirely different process than burning food
(I)～(V) - Perspective from my intestinal starvation theory
<Conclusions>
Many experts still believe that “one calorie is one calorie.” If we apply this idea to weight control, we have to only be concerned with the number of calories in our diet, regardless of what different foods we eat or how we eat them. Of course, the human body is not that simple, and many researchers have warned against this kind of thinking.
In explaining this, I thought I should make a distinction between reactions that occur "inside" the body (after absorption) and those that occur “outside" the body (before absorption) (*1).
In this article, I would like to consider the Atwater coefficient, which is the basis for calorie labels on food products, as an issue that occurs outside the body.
As many gut microbiologists recognize, the digestive organs such as the stomach and intestines are "external" to the body (e.g. bad bacteria in the gut do not directly harm the body), which is perfectly consistent with what I have been explaining in this blog－the idea that the "absorption rate is important."
( *1: "Diet-induced heat production" actually occurs after absorption, but it is related to digestion, so I’d like to also use it here to explain it as an external response.)
1. What is the Atwater coefficient in the first place?
In the 1800’s, chemists developed a method to measure the amount of calories in food by burning food and measuring the temperature change from its surroundings.
Burning food is chemically similar to the process by which our bodies break down food to obtain energy.
Much of what we know about food calories is said to come from the research in the late 19th century by Wilbur Atwater at Wesleyan University in Connecticut, who conducted a variety of experiments aimed at understanding human metabolism and the energy content of different foods.
By feeding volunteers various foods and calculating the difference in the heat of combustion between the food and the excreta, he approximated the calories absorbed by his volunteers. It is said that Atwater also took into account the dietary fiber which we can’t digest (*2), and proteins, some of which are excreted in the urine as urea after being absorbed.
More than one-hundred-twenty years after this experiment, these "Atwater coefficient" are still the basis for caloric calculations for all foods[1].
( *2: It is now known that dietary fiber produces some energy through fermentation and breakdown by the bacteria in the large intestine[2].)
Currently, the general Atwater coefficients of 4kcal/g for carbohydrate and protein, 9kcal/g for fat, and 7kcal/g for alcohol are applied to all foods regardless of the type of food.
The use of specific Atwater coefficient is also allowed, which is different for each food group[3].
2. Digestion is an entirely different process than burning food
We ingest food and then break down complex food molecules into simple structures such as glucose and amino acids by various digestive enzymes. After that, we get an energy source by absorbing them. Naturally, this is a completely different process compared to burning food in the laboratory.
According to Professor Rob Dunn (North Carolina State University), every calorie count on food labels is based on estimates or approximations, and are not an accurate reflection.
Recent research has revealed that how many calories we get from a given food depends on a variety of factors, including which species we eat, how we cook food, which bacteria are in our gut, and how much energy we use to digest different foods (diet-induced heat production).[4]
(I)Digestibility varies even in vegetables
Even if it is same vegetable group, they vary in the firmness of their leaves and stems. The cell walls of plant cells in the stems and leaves of some species are tough, whereas those of spinach, cucumber, and lettuce, etc. are soft and more than 90% of them are water.
Also, even in the same plant, the durability of cell walls can differ. The older the leaves, the tougher the cell walls tend to be and the more difficult they are to digest.
Seeds such as corn and nuts, in particular, have such sturdy cell walls that they can hoard precious calories within them and pass through the body intact[4].
A study by Janet A. Novotny at the U.S. Department of Agriculture (2012) found that when people eat almonds, they take in just 129 kcal per serving, not the 170 kcal listed on the label. It is beginning to be proven that nuts such as peanuts, almonds, and walnuts have a more robust cellular structure than other foods with similar levels of energy sources, and that their cell walls limit digestion. It is possible that the Atwater coefficient overestimates the digestibility of nuts.[5]
(II)Calories vary depending on how we cook food
Prof. Dunn also mentions that the biggest problem with modern calorie labels is that they failed to account for how food is prepared and processed, which dramatically changes the amount of energy derived from food.
We humans learned to cook raw food. We learned to process foods in different ways such as simmering, baking, frying, or even fermenting, to make them more palatable and tender.
This should have dramatically increased the calories we extracted from food [4].
Furthermore, some have pointed out that industrial food processing not only exposes food to high temperatures and pressures, but also softens food by adding air, to make it even easier to get more calories.
Corn, for instance, which is considered indigestible, is made into potage, and raw peanuts are roasted and processed into peanut butter. These processes must have dramatically increased the amount of energy available to the body. In other words, not all pork dishes are the same. The energy used for digestion and the absorption rate differ when roasting a chunk of pork versus making it into pâté.
(III)Energy required for digestion and immunity
Some research has shown that the energy required for digestion is not the same. This is called “diet-induced thermogenesis,” and it requires a great deal of energy to convert proteins into amino acids, fats into fatty acids, and carbohydrates into glucose. It is said that when proteins are broken down into amino acids, they require much more energy to digest than fats, because enzymes must unravel their tightly wound bonds[6].
It also differs between whole grains and refined wheat. A 2010 study found that people who ate 600-or 800-kcal portions of whole-wheat bread with sunflower seeds, kernels of grain, and cheddar cheese, expended twice as much energy to digest that food as those who ate the same amount of white bread and "processed cheese products.” Consequently, those who ate whole-wheat bread substantially obtained ten percent fewer calories, they said[7].
Many Japanese and Koreans traditionally love to eat raw fish or meat, if they’re fresh.
However, raw meat, for example, has been found to harbor many dangerous microbes, and our immune systems use energy to identify and deal with those pathogens[4].
It is possible that the same amount of cooked meat takes less energy to digest than steak tartare and has more usable calories .
(IV)Differences in digestive enzymes and intestinal bacteria
Most babies have lactase, an enzyme necessary to break down lactose sugar in milk, but it is said that most adults don’t produce this enzyme.
It has also been found that when starches such as rice and spaghetti are left to cool after being cooked, some of these starches crystallize into structures that digestive enzymes cannot easily break down.
What’s more, some microbes are present only in specific ethnic groups. Some Japanese, for example, have a microbe in their intestines which is suitable for breaking down seaweed. It has been found that these intestinal bacterium stole the seaweed-digesting genes from a marine bacterium that lingered in raw seaweed [4].
(V)There are variations for the method of calculation
The general Atwater coefficients were calculated based on the average daily diet of Americans at the time. Digestibility for carbohydrates, fats, and proteins were assumed to be 97, 95, and 92 percent respectively, and after adjusting a little for this, protein and carbohydrates were set at 4kcal/g, fats at 9kcal/g, and alcohol at 7kcal/g[8]. Although metabolizable energy values vary slightly for proteins, depending on whether they are vegetable or animal protein, and for carbohydrates, depending on whether they are sugar or starch, the coefficients were derived by a system of an average.
On the other hand, specific Atwater coefficients are also allowed, which divides food into several groups and applies a representative coefficient of that group to the entire group.
It is said that the U.S. Food and Drug Administration (FDA) allows a total of five variations on the theme including these, and some point out that depending on the method chosen by the food company, there may be variation on the calorie labels[9]. When such uncertainties add up, the daily caloric intake could vary widely.
<Summary of this section>
Prof. Dunn mentions as follow:
(1) It is possible to modify the Atwater system for every food group, as in the almond example. However, this would require a challenge to reexamine the amount of nutrients retained in the excreta for every food.
(2) However, even if we completely revised calorie counts, they would never be accurate because how many calories we extract from food depends on a complex interaction between food, the human body, and its many microbes. In particular, the process of digestion is so complex that it is probably impossible to derive an accurate formula for calorie calculation that will suit everyone.
(3) Instead, we should think more carefully about the energy we get from food in the context of human biology. Processed foods are easily digested in the stomach and intestines, and thus provide a lot of energy for very little work. On the other hand, vegetables, nuts, and whole grains require more sweat to digest, offer far more vitamins and nutrients than processed foods, and keep our gut bacteria happy[4].
3. Perspective from my intestinal starvation theory
I believe that researchers and nutritionists at that time, including Atwater, were committed to ensuring that people could have an adequate amount of nutrition, and the calorie counting system they created had great merit. But I suspect it has been misperceived by some and is now causing problems with those who are overweight.
The reason why the issue of being overweight remains unresolved indefinitely is because many people are too fixated on the caloric value of foods.
Let's say you eat, as in the example in the section 2-[III], 400kcal of a meal: whole-wheat bread, nuts, and grilled chicken. Assuming that, after taking into account the energy required for digestion, you obtained ten percent fewer calories (360kcal), the argument that "wouldn't it be the same if you ate 360 kcal worth of white bread and chicken terrine?" is complete nonsense.
Fibers from whole-wheat bread and nuts tend to remain undigested in our intestines, which means there is a message to the body of "there is still food," but the combination of white bread and easily digestible protein, etc. is quickly digested, and if the "three factors + one" of my theory are met, the intestinal starvation message saying "there’s no food" would be sent to the brain through the small intestine.
In other words, you can gain weight despite a reduction in total daily caloric intake.
I I have been explaining throughout this blog that the fundamental difference between obese people and lean people can be explained by the difference in set-point weight, and that having a higher set-point weight is related to an increase in absorption efficiency, which is induced by intestinal starvation. In addition, since one of the key factors causing intestinal starvation is how fast you digest food, both digestion and absorption ability are extremely important in my theory.
Nevertheless, if we believe that only numbers based on averages of subjects are all we have, we ignore them. As Prof. Dunn mentions, I don’t believe that the complexity of digestion and absorption for a diverse population can be described by a system using an average.
(Please read the following article for other issues in "calorie counting.")
There is No Meaning in Simply Calculating Calories You Consume
Conclusions
The Atwater coefficients is a measure of how much energy we can obtain from food, but I think it is inadequate to address the problem of obesity. Even if we revised the Atwater coefficients more accurately by taking into account energy required for digestion and food composition, the obesity problem will not be solved if we judge things only by the number of calories.
One idea that has been suggested by some researchers is to introduce a "traffic-light" system on food labels, alerting consumers to foods that are highly processed (red dots), lightly processed (green dots) or in-between (yellow dots) [10], and I agree with this idea. It is also possible to combine satiety, the number of chews, and the indigestibility of food into this traffic-light system.
What we need now, I believe, is to take a little away from the apparent accuracy of "calorie counting," which seems more scientific, and rethink our traditional diets and eating habits.
This overlaps with what Prof. Dunn has also pointed out, but eating traditional fibrous vegetable dishes, unprocessed meat or fish, dairy products, fermented foods, and whole grain breads, etc., cannot be judged by caloric benefits alone.
Those foods contain far more vitamins and minerals than processed foods, and their fiber content keeps our gut bacteria in good condition, gives us moderate satiety, prevents rapid absorption of glucose, and provides many other health benefits. Depending on how you eat them, it should be possible to lose weight without worrying about caloric intake.
References:
[1]Giles Yeo. Calories on food packets are wrong–it's time to change that. 2021.
[2] Japan Food Research Laboratories. The Energy in Food. 2003.
[3] The Nutrition Coordinating Center (NCC). Primary Energy Sources.
[4] Rob Dunn. Science Reveals Why Calorie Counts Are All Wrong. 2013.
[5]Novotny JA et al. Discrepancy between the Atwater factor predicted and empirically measured energy values of almonds in human diets. Am J Clin Nutr. 2012 Aug;96(2):296-301.
[6]Westerterp KR. Diet induced thermogenesis. Nutr Metab (Lond). 2004 Aug 18;1(1):5.
[7]Barr SB, Wright JC. Postprandial energy expenditure in whole-food and processed-food meals: implications for daily energy expenditure. Food Nutr Res. 2010 Jul 2;54.
[8]Kazuko Takada. Absorption and Utilization of Energy in the Body. Physical Fitness Science. 2007, Pages 56, 288.
[9]Cynthia Graber, Nicola Twilley. Why the calorie is broken. BBC future. 2016.
[10]Richard Wrangham, Rachel Carmody. Why Most Calorie Counts Are Wrong. Harvard University. 2015.
12/18/2022
The Atkins Diet: What Were the Long-Term Effects of Weight Loss?
Contents
- What is the Atkins diet?
- Comparative study of various diets in weight loss
- What were the long-term results of the Atkins diet?
- Why was obesity rare among rice-eating Asians?
- Is the Atkins also ineffective for weight loss?
<The bottom line>
1. What is the Atkins diet?
The Atkins diet is a type of low-carbohydrate diet proposed by cardiologist Robert Atkins that restricts the amount of carbohydrates for energy and instead uses "fat" as an energy source. It is characterized by limiting carbohydrates to twenty to twenty-five grams per day for the first two weeks and then gradually increasing.
According to Dr. Fung, the author of “The Obesity Code,” Dr. Atkins weighed nearly one-hundred kilograms in 1963, and when he began working as a cardiologist in New York City, he needed to lose weight.
However, he couldn’t lose weight successfully on a conventional calorie-restricted diet, so he tried the low-carb diet based on the medical literature, which worked well as advertised, and he recommended it to his patients.
In 1972, he published "Dr. Atkins' Diet Revolution," which quickly became a bestseller.
At the time, it was said that the American Medical Association still considered high fat in the diet to be a cause of heart disease and stroke, and the "low-carb diet," which allowed people to eat as much meat and fat as they wanted, was not accepted.
Despite this, the low-carb diet’s popularity, rekindled in the 1990’s, led to a trend in the Atkins diet. In 2004, twenty-six million Americans said they were on some kind of low-carb diet .
New studies started appearing around 2005, comparing the Atkins diet to other diets that were once considered the standard, and what were the results[1]?
Let's take a look. I would like to express my thoughts on this at the end of this article.
2. Comparative study of various diets in weight loss
"In 2007, the Journal of the American Medical Association published a more detailed study: Four different popular weight plans were compared in a head-to-head trial.
One clear winner emerged-the Atkins diet. The other three diets (Ornish, which has very low fat; the Zone, which balances protein, carbohydrates and fat in a 30:40:20 ratio; and a standard low-fat diet) were fairly similar with regard to weight loss.
However, in comparing the Atkins to the Ornish, it became clear that not only was weight loss better, but so was the entire metabolic profile. Blood pressure, cholesterol and blood sugars all improved to a greater extent on Dr. Atkins's diet.
In 2008, the DIRECT (Dietary Intervention Randomized Controlled Trial) study reaffirmed once again the superior short-term weight reduction of the Atkins diet. Done in Israel, it compared the Mediterranean, the low-fat and the Atkins diets.
While the Mediterranean diet held its own against the powerful, fat-reducing Atkins diet, the low-fat AHA standard was left choking in the dust–sad, tired and unloved, except by academic physicians."
(Jason Fung. The Obesity Code. Greystone Books, 2016, Pages 100-3.)
3. What were the long-term results of the Atkins diet?
"Longer-term studies of the Atkins diet failed to confirm the much hoped-for benefits.
Dr. Gary Foster from Temple University published two-year results showing that both the low-fat and the Atkins groups had lost but then regained weight at virtually the same rate. (*snip*)
A systematic review of all the dietary trials showed that much of the benefits of a low-carbohydrate approach evaporated after one year.
Greater compliance was supposed to be one of the main benefits of the Atkins approach, since there was no need for calorie counting.
However, following the severe food restrictions of Atkins proved no easier for dieters than conventional calorie counting.
Compliance was equally low in both groups, with upwards of 40 percent abandoning the diet within one year.
In hindsight, this outcome was somewhat predictable. The Atkins diet severely restricted highly indulgent foods such as cakes, cookies, ice cream and other desserts.
These foods are clearly fattening, no matter what diet you believe in. We continue to eat them simply because they are indulgent. (*snip*)The Atkins diet does not allow for this simple fact, and that doomed it to failure.
The first-hand experience of many people confirmed that the Atkins diet was not a lasting one. Millions of people abandoned the Atkins approach, and the New Diet Revolution faded into just another dietary fad. (The company Dr. Atkins founded in 1989 went bankrupt.)
But why? What happened?
One of the founding principles of the low-carbohydrate approach is that dietary carbohydrates increase blood sugars the most. High blood sugars lead to high insulin. High insulin is the key driver of obesity. Those facts seem reasonable enough. What was wrong?"
(Fung J. The Obesity Code. Pages 100-3.)
４. Why was obesity rare among rice-eating Asians?
Experts who advocate low-carbohydrate diets seem to think that carbohydrates cause weight gain because they eventually stimulate insulin secretion.
However, Dr. Fung mentioned that the carbohydrate-insulin hypothesis is incomplete. Various problems are cited, but he raised the "paradox of the Asian rice eater" and the "diet of Kitava Island, in Papua New Guinea" as notable examples.
Most Asians have been eating a diet based on refined rice as their staple food for at least the last five decades; a study conducted in the late 1990’s found that carbohydrate intake in China and Japan was similar to or rather, higher than in the U.K. and the U.S.
Nevertheless, until recently, obesity was not a significant problem in both countries.
Also, according to a study conducted by Dr. Staffan Lindeberg in 1989 on the diet of the Kitava islanders, even though they were getting sixty-nine percent of their calories from carbohydrates such as yams, sweet potatoes and cassava, etc., their insulin levels were low and few people were obese[2].
Since Dr. Fung just mentioned the paradox of the Asian rice eater, I would like to mention this.
I am Japanese and was born in 1970, and I think that I should know how our diet has changed in the last five decades, and as a result, how obesity has increased in our society.
(This is explained in more detail in the following blog.)
[Related article] Why Does the Body Perceive That It Is More Starved than in the Past?
In short, I believe that carbohydrates are a contributing cause, but not the quantity itself.
Japan was basically an agrarian society, and rice cultivation has always been important. Until at least 40-50 years ago, I believe most Japanese people had eaten a lot of rice as it is called the staple food, but at the same time, they also ate a lot of fibrous vegetable dishes using roots or stems of plants, fermented soybean product called “natto,” and fish and meat dishes. Rice cakes called “mochi” and Japanese sweets as well.
At least in my family, my father was strict about family members eating meals three times a day at a regular time, every day.
I think the recent increase in the obesity rate in Japan can be explained due to a combination of many factors, including easily digestible carbohydrates such as bread and noodles, unbalanced diets with few vegetables, eating out, instant foods, and irregular life rhythms such as skipping breakfast or late dinners.
What I have seen in my experience is that many young women who go on a diet and then come off, some of them further increase their maximum weight.
（Irregular lifestyle）
I believe that the "three factors plus one" of my intestinal starvation theory can explain how the various factors intertwine, and how weight gain occurs. It's not just the amount of carbs eaten that matter.
5. Is the Atkins also ineffective for weight loss?
The "Do calories make people fat, or carbs?" concept is said to be a debate that has been going on since the 1800’s[3], and I think both are true in some ways, but neither is perfect.
If you reduce the amount of any energy source beyond what your body needs, it’s obvious that you will lose weight in the short term. However, if you go back to your original diet, in the long run, you will also regain the weight you had lost, as various studies have confirmed, and as most people who have been on a diet have probably realized.
The reason for this is that the human body, I believe, basically works to maintain the status quo, and tries to go back to its set-point. So, the point is that in order to avoid rebounding, you must lower your set-point weight itself.
(For more information on how to do this, please see the following article.)
[Related article] There Are Two Steps to Lose Weight the Right Way
In terms of this rebound in the Atkins diet in section three, I don't think it necessarily means that low-carb diets, including Atkins, are ineffective. I’m positive that it’s the one of the correct ways to lose weight.
However, if we focus too much on blood sugar and insulin levels, we lose sight of another important point.
What I mean is that, the point of a low-carb diet, I believe, is not only the reduced carbohydrate amount, but also "how we increase the amount of other indigestible foods including meat, fat, fibrous vegetables, dairy products, etc." By sending plenty of indigestible foods to the gastrointestinal tract, we should feel less hunger and, in turn, the absorption rate should decrease. In particular, fats and oils in the diet should not be reduced, but rather should be consumed at every meal and even when having snacks.
From that point of view, I think that dieticians did not need to ban sweets such as chocolate, candy, ice cream, etc. so strictly. What is important is to be able to have them occasionally and not be too hard on yourself.
The bottom line
(1) In the early 2000’s, the Atkins diet became a huge trend in the U.S., inspired by the low-carb diet that was rekindled in the 1990’s. In the short term, the Atkins method not only helped people lose weight, but it also significantly improved blood pressure, cholesterol, and blood glucose levels.
(2) However, in long-term studies, the subjects rebounded, as seen with low-fat diets. After one year from the end of the study, all the benefits of Atkins diets were gone.
Dr. Fung considered the "carbohydrate-insulin hypothesis" an incomplete theory. Carbohydrate intake itself was not the problem.
(3) My thoughts. If there is no change in your set-point for body weight, rebound can occur if you eat as you used to. In order to lose weight correctly, your set-point weight itself needs to be lowered.
(4) The point of a low-carbohydrate diet is not just the amount of insulin secreted. I believe that it’s rather important to "take in more indigestible foods other than carbohydrates, and not feel hungry."
<Reference>
[1] Jason Fung. The Obesity Code. Greystone Books, 2016, Pages 96-99.
[2] Jason Fung. The Obesity Code. Pages 103-105.
[3] Gary Taubes. Why We Get Fat. New York: Anchor Books, 2011, Pages 148-162.