Health

Here's a quick summary:

1. Cortisol, despite the bad reputation it has in weight training and bodybuilding, is needed to maintain optimal health and can even burn fat under the right circumstances.
2. Both chronically elevated and continuously suppressed cortisol levels can be destructive. The right balance is key.
3. During exercise, cortisol levels should be high, as cortisol works with your other fat-burning hormones during this phase to increase the release of fat.
4. Cortisol can cause cravings for junk food while simultaneously shutting down the goal-oriented areas of the brain and activating the reward centers of the brain. This is a bad combination for dieters.
5. The three best ways to control cortisol levels are diet, exercise and lifestyle. The three easiest ways to find out if your cortisol levels are balanced are to pay attention to hunger, energy and cravings (HEC, which stands for "Hunger, Energy and Cravings").

How many calories does stress have?

I admit that this is a silly question. You can't eat stress! But this question addresses a crucial point that the entire health and fitness world seems to overlook: it's not calories that control your metabolism, it's your hormones. And when it comes to hormones, the stress hormone cortisol is crucial.

Stress hormones can not only affect how many calories you eat in a day - they can also affect the quality of the calories you eat and have an impact on where those calories are stored or burned. But if all this is true, how does it actually work? And what can you do to influence it?

What exactly is cortisol?

The best way to think of hormones is to think of them as cellular messengers. They provide cells inside the body with information about what is happening outside the body. A good way to think of cortisol is to think of this hormone as a 110 hormone. It sends a signal to emergency services such as the fire department and police, who are the first to be activated in an emergency. Cortisol plays both a protective and an adaptive role. It counteracts inflammation and releases energy from the body's glycogen (sugar) and fat stores to meet the increased energy needs caused by stress. Anything that poses a potential threat to the body will result in a release of cortisol.

Dr. Jekyll & Mr. Hyde

I like to refer to cortisol as the Jekyll & Hyde hormone. As you probably remember, Dr. Jekyll was a kind, upstanding citizen who was plagued by dark thoughts from time to time. These troubled him, which is why he developed a serum that separated him from his dark impulses. However, this only partially worked and split his personality, giving birth to his diabolical alter-ego Mr. Hyde. The story is about the struggle between the good, balanced side of Dr. Jekyll and the evil, extreme side of Mr. Hyde.

This is also a good way to visualize cortisol. Many people think of cortisol as an evil hormone that stores fat and makes their muscles shrink. However, the fact is that this hormone is needed for optimal health and can even burn fat under the right circumstances. There is no question that cortisol can become destructive in certain situations, including when its levels are chronically elevated or when it is persistently suppressed. When cortisol levels are too high or too low, it turns into the devilish Mr. Hyde. When its levels are balanced, it is more like the helpful Dr. Jekyll.

Hormonal sociability

Hormones are like people - they behave differently depending on their environment and the people/hormones that surround them. High cortisol levels in a state of low calorie intake, for example, will have different effects than high cortisol levels in a state of high calorie intake. Something similar applies to exercise - during exercise, high cortisol levels are beneficial, while at other times lower cortisol levels are desirable.

During exercise, cortisol works with your other fat-burning hormones - the catecholamines (adrenaline and noradrenaline) and growth hormones - to increase the release of fat. And what about high cortisol levels when you're not exercising? That's a completely different story. When cortisol has a social gathering with insulin, it has exactly the opposite effect.

Cortisol & insulin

Understanding these hormonal interactions is important. Technically, cortisol is both a fat-storing and a fat-burning hormone. This is because it increases the activity of lipoprotein lipase (LPL) - the body's primary fat-storing hormone. But it also increases the activity of hormone-sensitive lipase (HSL), which is the body's primary fat-releasing enzyme.

Growth hormone and catecholamines, whose levels are elevated during exercise and fasting, enhance the fat-burning potential of cortisol while suppressing its fat-storing potential. In the non-fasting state, when insulin is present in high amounts, HSL activity is significantly downregulated while LPL activity is increased. In this way, insulin enhances the fat-storing properties of cortisol while blocking its fat-burning activity.

Cortisol and insulin also block each other's actions by reducing the sensitivity of each other's receptors. This means that eating is not the only way to become insulin resistant - stress can also cause insulin resistance. So, contrary to what you are always told, cortisol is not really a belly fat storing hormone. Insulin and cortisol in combination with a high-calorie diet are the real cause of fat storage in the abdominal area.

Cortisol & the thyroid gland

Another dual action of cortisol is the way it interacts with the primary metabolic fat-burning machine - the thyroid gland. Cortisol and the catecholamines sensitize the thyroid receptors. Low cortisol levels can therefore lead to low thyroid function. High cortisol levels, on the other hand, block the normal conversion of inactive thyroid hormones (T4) into active thyroid hormones (T3). Ultimately, cortisol levels should therefore be neither too high nor too low, but just within the right range.

Cortisol & hunger

Two things are needed for fat loss - a calorie deficit and hormonal balance. Cortisol influences hormonal balance, but it also influences calories. Cortisol influences several hormones that are responsible for hunger and cravings. These include leptin, insulin and neuropeptide Y (NPY).

The command and control center of your metabolism is an area of the brain called the hypothalamus. This is the center of your metabolic sensor/thermostat. This area must be able to "hear" the signals sent by peripheral hormones such as leptin and insulin, both of which turn off hunger under normal circumstances. Chronically elevated cortisol levels lead to downregulation of hormone receptors, resulting in hormone resistance.

Imagine walking into a room with a strong odor and covering your nose and mouth - only to realize later that you can no longer smell the stench. This is what cortisol does to your brain. It dampens the mechanisms that perceive satiety. This makes it much less likely that you will feel full and satisfied after a meal and much more likely that you will eat more at the current and future meal. Cortisol & cravings

Cortisol is also involved in cravings. Through mechanisms that are not yet fully understood, cortisol, along with other stress hormones (i.e. the catecholamines), increases cravings for more palatable foods with a higher calorie density. It does this while simultaneously shutting down the goal-oriented centers of the brain and activating the reward centers of the brain. This is a bad combination if you want to stick to your diet. In other words, there's a reason we want the three-story burger at Mc Doof instead of the chicken breast and broccoli already in the fridge when we're stressed. And cortisol could be part of the reason.

How stress makes you fat

If you're a smart fitness enthusiast, then when you think of stress, you think of cortisol. If you really know your stuff, you'll also think of catecholamines. But there's another hormone that's released during stress that even the most advanced experts don't know much about - NPY.

NPY, as mentioned above, is involved in hunger in the brain. But cortisol not only affects NPY levels in the brain, it also affects NPY levels in the body. When you are exposed to acute stress, your body releases catecholamines and cortisol. When you are exposed to chronic stress, your body releases more NPY. When catecholamines and cortisol team up, they help you burn fat. But NPY makes you put on fat - especially when it "hangs out" with cortisol.

When NPY is released in large amounts, it causes immature fat cells to mature into mature fat cells. Chronically elevated cortisol levels make the body more susceptible to this fat-storing action of NPY. In other words, NPY increases the growth of fat cells and cortisol makes it more efficient at doing so. If you're confused now, here's what I just said again:

1. Cortisol combined with catecholamines - as is the case with short-term stress - helps us burn fat.
2. Cortisol in combination with NPY - as is the case with chronic stress - is synonymous with increased fat storage.

Belly fat is a parasite

Cortisol is largely produced in the adrenal cortex, but there is another place where it can be produced - belly fat. The fat that sits deep in the abdomen, also known as visceral fat, contains an enzyme called 11-beta hydroxysteroid dehydrogenase (11-HSD). This is an enzyme that converts inactive cortisone into cortisol. This means that belly fat can produce its own cortisol!

And in another twist on the complicated relationship between insulin and cortisol, insulin increases 11-HSD activity, which increases cortisol levels, which then cause increased insulin resistance. In this way, belly fat acts like a parasite, ensuring its growth at the expense of its host's health. I mention this because there are many situations where stubborn belly fat will not go away despite the best efforts at diet and exercise. Sometimes, therefore, an extra hour in bed to lower cortisol levels might be a better strategy than an extra hour on the treadmill.

Cortisol management

There's a lot more that could be said about cortisol, but let's look at some things you can do to control your cortisol levels. The three best ways to control cortisol are diet, exercise and lifestyle. And the three easiest ways to determine if your cortisol levels are in balance are to pay attention to hunger, energy and cravings (HEC for short). If your HEC is under control, then this is a rough indicator that your cortisol is too.

Meal frequency

Remember that cortisol is an alarm hormone. It may surprise you to learn that both eating and not eating can increase cortisol levels. Skipping meals can increase cortisol levels because your brain needs a constant supply of glucose. For some, skipping meals will cause blood sugar fluctuations that result in a cortisol response. When these people skip meals too often, it can result in many of the negative effects mentioned above. However, overeating can also increase cortisol levels. Cortisol, as mentioned earlier, is an alarm hormone that helps regulate the immune response, among other things. For those who are sensitive to certain foods, this effect can be pronounced.

When it comes to meal frequency, don't be too influenced by what the science zombies tell you. Let scientific research refine your approach - not define it. There are many approaches that can work. Eat regularly to keep your HEC under control. For some, this may mean lots of small, frequent meals. For others, it may mean less frequent, larger meals.

There is no one-size-fits-all approach here. Just remember that a healthy, low-calorie meal is neither healthy nor low-calorie if you devour half a cheesecake at the end of the day. And while there's been a lot of controversy lately about meal timing, one potential benefit of a post-workout recovery drink is a quick suppression of post-workout elevated cortisol levels.

Cortisol and training

Short intense training or training with weights and slow and relaxing training are best in terms of cortisol release. In the case of short, intense training sessions, cortisol levels are increased along with levels of catecholamines and growth hormone. This is good for fat burning. In addition, a shorter duration of exercise means less compensatory hunger later on and a lower risk of a catabolic state.

With prolonged moderate and intense exercise, cortisol can easily dominate over growth-promoting hormones and is associated with hunger and cravings after exercise, as well as lower anabolic potential. Is this why sprinters and marathon runners look so different? Probably not completely, but after considering genetic predispositions, it's not a big leap to assume that this mechanism plays a role.

Another great way to lower cortisol levels is to finish your workout with slow relaxing movements like leisurely walking. I'm not sure why it's not used more often, but slow walking is one of the best approaches to lowering cortisol levels. And it has been shown to be even more effective in this regard when done in the great outdoors.

Rest based living

And if you really want to beat cortisol, you should develop a new approach to what I call rest-based living. Find as many ways to do your rest & recovery training sessions. These include naps, sex/physical closeness, massage, fascia roller massage, laughter, time with pets, leisurely walking, sauna visits, hot baths, contrast showers, meditation, etc. All of these activities can be used to lower cortisol levels.

References

1. Schwabe, et al. Simultaneous glucocorticoid and noradrenergic activity disrupts the neural basis of goal-directed action in the human brain. Journal Neuroscience. July 2012;32(30):10146-55.
2. Epel, et al. Stress may add bite to appetite in women: a laboratory study of stress-induced cortisol and eating behavior. Psychoneuroendocrinology. January 2001;26(1):37-49.
3. Newman, et al. Daily hassles and eating behavior: the role of cortisol reactivity status. Psychoneuroendocrinology. February 2007;32(2):125-32.
4. Adam, et al. Stress, eating and the reward system. Physiology & Behavior. July 2007;91(4):449-58
5. Kuo, et al. Chronic stress, combined with a high-fat/high-sugar diet, shifts sympathetic signaling toward neuropeptide Y and leads to obesity and the metabolic syndrome. Annals of the New York Academy of Sciences. December 2008;1148:232-237.
6. Tsunetsugu, et al. Physiological effects of Shinrin-yoku (taking in the atmosphere of the forest) in an old-growth broadleaf forest in Yamagata Prefecture, Japan. Journal of Physiological Anthropology. March 2007;26(2):135-142.

Source: https://www.t-nation.com/diet-fat-loss/two-faces-of-cortisol

By Dr. Jade Teta

If eating late at night impairs fat loss, why do people who eat more in the evening lose more fat than people who don't?

If carbs make you fat after 6pm, how is it that people who eat more carbs after 6pm lose more fat than people who eat their carbs earlier in the day?

If we should eat breakfast like a king, lunch like a prince and dinner like a beggar, why does skipping breakfast combined with late night binge eating lead to fat loss and improved blood lipid levels?

If eating late is bad for you, why does almost every controlled scientific study show that eating later in the day is better than eating earlier in the day?

And if the above statements are true, why do people still believe that eating late is bad for you...?

The myth of eating late

There is a common belief among many people that it is better to eat more earlier in the day and less later in the day. Eating later in the day is said to impair fat loss and/or promote unwanted weight gain. This myth can best be summarized by the saying that you should eat like a king in the morning, like a prince at lunchtime and like a beggar in the evening.

You'll often find people clinging to the myth that carbohydrates will somehow suddenly make you fatter after 6pm - which is, of course, complete nonsense.

The facts on this are more interesting than what I have already said in previous articles on this topic. Controlled studies have repeatedly shown that a dietary pattern of eating later in the day is superior for fat loss and body composition.

In this article, I will look at some studies that look at the timing of calorie intake. I will follow the last study titled "Greater Weight Loss and Hormonal Changes After 6 Months Diet With Carbohydrates Eaten Mostly at Dinner" because it was this study that prompted me to revisit this topic in the first place.

A pressing question first: why is the myth about the negative effects of eating late at night still so widespread when there are so many studies showing the exact opposite?

Late night eating in nutritional epidemiology

In the comments on my site, a reader asked the following question:

"Is it okay to eat dinner 1 to 2 hours before bedtime? Every damn mammal goes to sleep after eating massive amounts of food - e.g. lions, dogs, bears, but at some point nutritionists came to the conclusion that we have somehow evolved. It would therefore be nice if someone could produce scientific evidence to show that we shouldn't eat before bedtime. I really don't understand why this should be the case, do you have an explanation for me?"

Yes, how did nutrition experts come to the conclusion that eating before bedtime is bad for you?

The late night eating myth is mainly another consequence of the confusion between correlation and causation in the field of nutritional epidemiology. There are numerous observational studies that have observed a positive correlation between calories consumed in the evening and higher BMI in the general population.

This correlation can be attributed to the fact that the average person who likes to eat more in the evening also consumes more calories overall. One study used food logs to find that late-night eaters consumed an average of 248 kcal more than members of the other group.

Similar relationships can usually be found in other observational studies on meal patterns. People who skip breakfast, skip other meals and eat late at night are on average fatter and worse off than people who eat breakfast, eat regular meals and eat less in the evening. However, this has nothing to do with meal timing per se, but more with the lifestyle that goes hand in hand with "dysregulated" eating habits.

A meal pattern that skips breakfast or breakfast and lunch has been associated with an accumulation of less healthy lifestyle factors and poorer food choices, leading to an overall poorer diet. ("Meal pattern, food choice, nutrient intake and lifestyle factors in The Göteborg Adolescence Study", https://www.ncbi.nlm.nih.gov/pubmed/14647222)

Late night eating was correlated not only with higher calorie intake, but also with less sleep time and more sedentary activities such as watching TV and spending time in front of the computer, which are other confounding factors that can promote weight gain.

Shift work and the internal clock

The purported risks of late-night eating may also be the result of the scientific literature on shift workers and metabolic health ("Shift work and the risk of metabolic syndrome: a nested case-control study.", https://www.ncbi.nlm.nih.gov/pubmed/21618947). Shift workers are predisposed to a variety of health problems, obesity, poor mental health, cardiovascular disease, stomach ulcers and gastrointestinal problems (probably the result of chronic stress).

The negative effects of shift work on health are mainly the result of a compromised diet, sleep deprivation and stress - the factors tend to go hand in hand. However, it is possible that eating in a state of disrupted day-night rhythm and an irregular meal pattern is an independent factor in predisposing shift workers to poor health.

People can adapt to a variety of different eating patterns depending on their habitual meal pattern. This adaptation takes place at a cellular level and is regulated by ghrelin - a hormone that is released in greater quantities during habitual mealtimes and prepares your metabolism to best cope with the upcoming load of food. Similarly, the day-night rhythm - when you wake up and when you go to sleep - is regulated by daylight and the habitual sleep/wake cycle and also adjusts your metabolism accordingly.

Simply put, your body expects a certain routine every day depending on your habitual eating patterns and sleep/wake rhythm and adjusts its hormonal profile and metabolism. If this pattern is arbitrary and constantly shifted forward and backward, never allowing your body to adjust, as is the case with many shift workers, then it is very possible that this is an independent factor that makes people more susceptible to disease and health problems. The hormonal profile of shift workers, moreover, tends to be less favorable than that of people with a regular circadian rhythm.

It should be noted that permanent shift workers, i.e. those who always work at night or work several nights in a row, are better off than other shift workers, which can be partly explained by a change in the day-night rhythm. It seems that an "unpredictable" schedule, i.e. rotating day and night shifts, is the main culprit, as the day-night rhythm is constantly disrupted. Given the many confounding factors such as stress, sleep deprivation, caloric intake, etc. present in shift workers, it is difficult to isolate which factor is responsible for what - i.e. is food intake during the biological night worse than sleep deprivation, etc.

Nutritional epidemiology vs. controlled studies

We are not interested in the studies mentioned above. What we are interested in are controlled studies - not nutritional epidemiology and observation in the general population. If you use nutritional epidemiology to tell people how they should eat, then you get the typical food pyramid. If you use controlled studies to draw your conclusions, you get something that is more meat- and vegetable-heavy.

Controlled studies answer questions like "I'm on a 2000 kcal diet. How will my fat loss be affected if I eat most of those calories later in the day or if I eat more of those calories earlier in the day?" This is something we are interested in, so let's take a closer look.

Early eating vs. later eating regimens: controlled studies

In all of these studies, calories were controlled and fixed in all groups. The only variable that differed was the timing of the daily calorie intake. In the later meal pattern, 67 to 100% of calories were consumed between 18:00 and bedtime and this was compared to an earlier meal pattern with the opposite timing of calories.

Let's start with the earliest study and work our way up to the most recent. I will briefly summarize the results, comment on the validity of the study, and interject whatever I find interesting about this study.

I want to note that I did not include any studies on Ramadan fasting. In only loosely controlled studies of Ramadan fasting, fat loss and improvements in health markers are usually observed. This is a paradoxical and interesting observation due to the fact that people eat in the middle of the night just before going to bed and usually eat even more sugar and baked goods than usual (and sometimes even more calories). However, in these studies, calorie intake is rarely actually controlled, i.e. participants did not have strict guidelines on what they should eat, which is the reason I did not use these studies in this review.

Study #1

Chronobiological aspects of weight loss in obesity: effects of different meal timing regimens.(https://www.ncbi.nlm.nih.gov/pubmed/3508745)(Chronobiological aspects of weight loss in obesity: effects of different meal timing regimens)

Results: This first-ever calorie-controlled study on meal timing, conducted in 1987, found that weight loss did not differ if subjects ate their daily calorie intake in the morning (10 am) or evening (6 pm).

Although it is interesting to note that fat oxidation was consistently higher in the group that ate in the evening, the duration of the study (15 days) was very short, making it difficult to draw meaningful conclusions from it. Apart from the differences in fat oxidation, there were no differences in cortisol levels, blood pressure or resting energy expenditure between the two groups.

Study #2

The role of breakfast in the treatment of obesity: a randomized clinical trial.(https://www.ncbi.nlm.nih.gov/pubmed/1550038)(The role of breakfast in the treatment of obesity: a randomized clinical trial).

Results: In this well-designed 12-week study, the subjects were people who habitually ate breakfast and people who did not normally eat breakfast. Interestingly, fat loss was greatest in people who normally ate breakfast but skipped breakfast during the study. This group ate lunch and dinner and consumed 2/3 of their daily calories at dinner (6:00 pm or later).

The subjects who did not normally eat breakfast and who now ate breakfast achieved more positive results than those who continued to skip breakfast as usual. The implication of these seemingly paradoxical results could be related to impulse control - dysregulated eating habits such as not eating breakfast tend to go hand in hand with unrestrained or impulsive eating. Eating breakfast could therefore be beneficial for those with poor self-control, such as the former breakfast deniers in the study.

On the other hand, more desirable results could be achieved for the "controlled" eaters (habitual breakfast eaters) who now abstained from breakfast. This group would be more representative of us - i.e. people who are used to counting calories, following an organized diet and not just carelessly eating what is in front of us.

Incidentally, there were no differences between the groups in terms of weight loss composition (75% fat / 25% lean body mass) or metabolic rate at rest.

Interesting tidbit: The group that ate breakfast showed a slight increase in depression-induced eating, while subjects in the group that did not eat breakfast showed a slight reduction. In addition, subjects in the breakfast group viewed their diet as more restrictive than subjects in the group that did not eat breakfast.

Here is a quote from the study:

"...the larger meal size in the group that did not eat breakfast caused less disruption to meal schedules and social life than the smaller meal size in the group that ate breakfast."

Perhaps it was these beneficial effects on social life that also resulted in the non-breakfast group showing better continued adherence to the modified diet during the 6 months following the study (81% vs 60%).

Study #3

Weight loss is greater with consumption of large morning meals and fat-free mass is preserved with large evening meals in women on a controlled weight reduction regimen.(https://www.ncbi.nlm.nih.gov/pubmed/9040548)(Weight loss is greater with consumption of large morning meals but fat-free mass is better preserved with large evening meals in women on a controlled weight reduction regimen).

Results: In this study, subjects alternated between two 6-week phases of the same diet in which 70% of daily calories were consumed either in the morning or evening. Larger morning meals compared to larger evening meals resulted in greater weight loss, but this weight loss consisted of muscle mass. Overall, larger evening meals maintained existing muscle mass better and resulted in a greater reduction in body fat percentage.

The greater weight loss associated with the larger morning meal eating pattern was primarily due to a loss of lean body mass, which was on average about 1 kilogram higher in the larger morning meal group than in the larger evening meal group.

An interesting study with a few obvious limitations, mainly that the number of subjects was very small at 10 participants and that body composition was measured using electrical conductivity - a method that is chronically inaccurate.

This study also involved training with weights three times a week, which was a serious confounding factor in this study. Considering that the group that ate the most calories later in the day ate a greater percentage of their calories after exercise, this study may also simply show the benefits of nutrient timing rather than larger meals in the evening per se.

Setup with larger food intake in the morning

• Breakfast, 8:00-8:30am: 35% of daily calorie intake
• Training with weights (circuit training), 9:00-9:30 a.m.
• Lunch, 11:00-12:00: 35% of daily calorie intake
• Dinner, 16:30-17:00: 15% of the daily calorie intake
• Evening snack, 20:00-20:30: 15% of the daily calorie intake

Setup for larger food intake in the evening

• Breakfast, 8-8:30 a.m.: 15% of daily calorie intake
• Training with weights (circuit training), 9:00-9:30 a.m.
• Lunch, 11:00-12:00: 15% of daily calorie intake
• Dinner, 16:30-17:00: 35% of the daily calorie intake
• Evening snack, 20:00-20:30: 35% of daily calorie intake

Finally, the scientists speculated on the muscle-sparing effects of the meal pattern with larger meals later in the day:

"Certain endocrine influences may have contributed to the differences in lean body mass changes between meal schedules. Growth hormone secretion reflects an endogenous rhythm that is partially related to the sleep cycle. At night, pulsatile growth hormone secretion increases after 1 to 2 hours of sleep, with maximal secretion occurring during stages 3 and 4 of the day.

Although the effects of prolonged changes in food intake or meal pattern on growth hormone release are not known, it is conceivable that a greater influx of dietary amino acids at evening meals, combined with the known protein anabolic effects of growth hormone, could promote lean muscle mass gain.

Study #4

Influence of meal time on salivary circadian cortisol rhythms and weight loss in obese women.(https://www.ncbi.nlm.nih.gov/pubmed/17483007)(Effects of meal timing on salivary circadian cortisol rhythms and weight loss in obese women).

Results: Using exactly the same setup as the previously mentioned Sensi & Capani (1987) study, it was found that dividing daily caloric intake into five meals eaten every other hour between 9:00 am and 8:00 pm, eating all calories in the morning (9:00 am to 11:00 am) or eating all calories in the evening (6:00 pm to 8:00 pm) did not differentially affect weight loss, metabolic rate, or cortisol levels. The limitation was again a very short duration of each phase (18 days).

Here is a quote for those who are concerned about cortisol and fasting:

"At the end of the phases of the study, regardless of the timing of food intake, we did not observe significant changes in the diurnal rhythm of cortisol secretion even after 22 hours of fasting."

It might be worth noting that nitrogen loss, which is a crude marker of muscle loss, was not affected by the timing or frequency of meals - there was no difference between the 5 meal phase and the 22 hour fasting phases in the morning/evening meals.

Study #5

Greater Weight Loss and Hormonal Changes After 6 Months Diet With Carbohydrates Eaten Mostly at Dinner.(https://www.ncbi.nlm.nih.gov/pubmed/21475137)(Greater Weight Loss and Hormonal Changes After 6 Months Diet With Carbohydrates Eaten Primarily at Dinner)

In this most recent and well-designed 6-month study of calorie distribution throughout the day, subjects who ate most of their daily carbohydrates at dinner (8:00 pm or later) lost more fat, felt fuller during the diet, and experienced more desirable hormonal changes than subjects who ate their carbohydrates earlier in the day.

Background: This study is based on the premise that the daily peak of leptin levels can be altered, as can be observed during Ramadan.

Previous studies have described the typical diurnal pattern of leptin secretion, which falls during the day from 8:00 am to 4:00 pm, reaches its lowest point at 1:00 pm, rises from 4:00 pm and reaches its maximum at 1:00 am. Ironically, this important hormone, which is responsible for satiety, has its highest levels when we are asleep.

It was hypothesized that consuming carbohydrates primarily in the evening could alter the typical diurnal pattern of leptin secretion as observed in Muslims during Ramadan.

Simply put, the aim of the study was to determine whether it is possible to shift leptin release to strategically achieve better satiety and dietary adherence in the morning and midday of the next day, rather than having the leptin peak during the night (as is the case with the standard diet).

"...it was predicted that this diet would lead to higher relative leptin concentrations starting at 6:00 to 8:00 am and throughout the day. This could lead to increased satiety during the daytime hours and improve dietary adherence."

At this point I should note that leptin shows a significant latency in response to carbohydrates - if you eat carbs before sleep, then you won't experience the peak of leptin release until you wake up in the morning (another bonus is that you'll sleep well with a few carbs before bedtime).

This study also wanted to examine the effects of the experimental diet on adiponectin:

"Adiponectin is thought to be the link between obesity, insulin resistance, and metabolic syndrome. Adiponectin plays a role in energy regulation and fat and carbohydrate metabolism, reduces serum glucose and lipid levels, improves insulin sensitivity and has anti-inflammatory effects. The pattern of daily adiponectin release has been described as low during the day in obese individuals (especially those with greater abdominal fat deposition)."

Low adiponectin levels = bad. High adiponectin levels = good.

When insulin levels are low, adiponectin levels are high, but adiponectin also follows a diurnal rhythm - low during the night, high during the day (in normal weight people).

"...it has also been hypothesized that increasing adiponectin concentrations during the day would improve insulin resistance, reduce symptoms of metabolic syndrome and lower levels of inflammatory markers."

In overweight people, chronically high insulin levels cause chronically low adinopectin levels, which is a problem because it increases insulin resistance and inflammation. The authors of the study hypothesized that by eliminating carbohydrates earlier in the day, adinopectin levels would increase more than with a conventional diet and health markers would also improve.

Setup: Both groups received the same diet split between breakfast, lunch and dinner and three snacks (morning, noon, late evening):

• 1300-1500 kcal
• 45-50% carbohydrates
• 30-35% fat
• 20% protein

Group A received the carbohydrates evenly distributed over meals and snacks. Group B received the majority of their total daily carbohydrate intake (approx. 170 grams) at dinner. There were no details regarding the exact macronutrient distribution of each meal, but the printed version of this paper includes the full meal plans for both groups. I would estimate that Group B consumed approximately 100 to 120 grams of carbohydrate during dinner.

Results: Both groups lost weight and saw improvements in different health markers, but Group B lost more weight (-11 kg vs. -9 kg), body fat (-7% vs. -5%), felt fuller and improved their hormonal profile better than Group A.

"Hunger levels were lower and there were greater improvements in fasting blood glucose levels, average daily insulin concentrations and homeostatic model assessment for insulin resistance (HOMAIR), T-cholesterol, LDL cholesterol, HDL cholesterol, C-reactive protein levels, tumor necrosis factor levels, and blood glucose levels compared to the control group. tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) levels."

As predicted, the high-carbohydrate dinner was able to alter the levels of leptin and adiponectin in a way that promoted better satiety and a better hormonal profile.

"The experimental diet modified leptin and adiponectin concentrations compared to baseline and control diet levels. A simple dietary manipulation of carbohydrate distribution appears to have additional benefits in people suffering from obesity compared to a conventional weight loss diet."

However, what I found most interesting - at least for those of us who want to maintain a low body fat percentage - was that the higher carbohydrate dinner increased average leptin levels compared to the standard diet.

"Our experimental diet could manipulate daily leptin secretion and lead to higher relative concentrations throughout the day. We hypothesize that this modification of hormone release helped study participants achieve better satiety during the waking hours of the day, which improved diet adherence in the longer term and led to better anthropometric outcomes."

This study was solid, but for some reason there was no mention of how body fat percentage was measured. In addition, calorie intake was not individualized and based on energy needs. However, since each subject had the same occupation (police officer), it is fair to assume that physical activities did not vary greatly on an individual basis. In addition, the sample size was quite large (78 subjects), making it unlikely that the results were biased by these factors.

Summary

Nutritional epidemiology usually finds associations between certain meal patterns and higher BMI/body fat percentage. However, the relationship can be attributed solely to lifestyle-related factors and dietary habits such as snacking while watching TV, generally poor food choices, etc. People who eat more in the evening simply consume more calories, which explains why they weigh more.

Calorie-controlled studies that look at the effects of varying the distribution of a fixed amount of calories throughout the day are few and far between - I've listed all of them above. These studies tell a completely different story than the studies found in the field of nutritional epidemiology. While short-term studies (15 to 18 days) find no statistically significant differences between meal regimens with earlier or later food intake, long-term studies (>12 weeks) show that dietary regimens with higher calorie intake later in the day produce superior results in terms of fat loss, body composition and/or diet adherence. This could be explained by more favorable post-meal nutrient partitioning due to hormonal modulation.

I understand that these facts will be hard for some people to swallow considering all the negative things they've heard about late-night eating. But then again, we hear a lot of strange things in the health and fitness community. And rarely do these tales match reality - just think of all the myths about fasting, alcohol and meal frequency.

That's it for today. I hope you've enjoyed this article and are now reassured that there's nothing wrong with eating late and eating big meals before bedtime.

Source: https://leangains.com/is-late-night-eating-better-for-fat-loss-and-health/