In Japan, many people (especially women) tend to avoid eating dinner, a 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.
     

While we sleep at night, our bodies are not resting. They are doing something very important for us. Although the mechanism may not be entirely understood, sleep is an important time for not only organizing and consolidating memories in the brain, but also for repairing and regenerating damaged tissues to prepare for the next day's activities. 

On the other hand, I sometimes hear that people did not gain weight when they were eating dinner around seven p.m., but gradually gained weight over time after working overtime and eating late at night.  But that is a separate issue from [1] above, and it can be explained by the fact of one’s base weight itself going up in my intestinal starvation theory. 

First of all, many people tend to skip breakfast if dinner is served late at night. This means, in most cases, they only have two meals a day, lunch and dinner.

In Japan, many experts confuse the two meanings of [1] and [2], and explain them as if the secretion volume of BMAL1(Brain and muscle Arnt-like protein-1 ) and weight gain are correlated.

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.

If people eat breakfast, lunch, and dinner properly, I believe, for most of them, eating before bed does not cause much weight gain.

As I said earlier, if a person who normally moderates their caloric intake eats sweets or ramen late at night, they may gain a few kilograms, but it means their present weight goes back to their base weight and should stop at a certain weight. (This should be easily proven by research.)

Also, In Japan, it is said that there are many thin people who have weak stomachs or droopy stomachs (gastroptosis), and even if they eat dessert, 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 they may even lose weight (at least to me, this is one hundred percent true).

(1) In relation to hormones secreted, protein and lipid synthesis may occur more during sleep, so in a sense, everyone should be more likely to gain weight with dinner than in the daytime. Especially those who usually eat fewer calories because of dieting will gain a few kilos if they eat more calories than necessary at night. But in this case it doesn't matter whether they eat at seven p.m. or ten p.m.

(2) In terms of my intestinal starvation theory, late-night eating habits can lead to an increase in weight. Those people tend to skip breakfast and eat two meals a day. If they eat a carbohydrate-rich, unbalanced meal for lunch and hold off until a late dinner, it can lead to inducing intestinal starvation and an increase in base weight over time.

(3) I believe it is unreasonable to correlate the secretion volume of BMAL1－a protein involved in the body's circadian rhythms－which is related to adipogenesis, with meal time, and that say that, “late night eating makes people gain weight.” This is because the time required for digestion and absorption is not taken into account.

(4) For some thin people who want to gain weight, eating a high-calorie meal or a sweet before bed in addition to their three meals a day would probably work in the direction of losing weight. Even while sleeping, energy is used more towards digestion and absorption, which may result in decreased cellular regeneration and the synthesis of protein and lipids.