Is it bad to eat a large meal right before going to bed?

The question of whether it is bad to eat a lot before going to sleep cannot be answered, because according to the latest studies, and if we focus on weight control, the evidence is no longer as clear as was previously thought. It is true that a large dinner can make digestion heavier and more difficult, leading to poor rest. But it depends on several issues such as, for example, what you eat (if there is a lot of protein, if there is a lot of fat). What’s more, there is no one-size-fits-all answer, because it depends on each person, their biological rhythms and what we know as chrononutrition, which is the study of nutrition based on this biological pace.

There are people who are evening people and others who are morning people. And that means that the answer to the question is that it depends on the metabolism of each individual, and how their digestive process takes place. When it comes to food, the fact is that we can generalize less and less. We already know, for example, that the old theory that eating too much for dinner causes weight gain is not supported by the latest studies. A recent study analyzed the difference in weight loss in people who ate a big breakfast and then ate less throughout the day, compared to people who ate very little for breakfast and ate more throughout the day, and whose biggest intake was in the evening. Weight gain was practically the same in both groups. This shows that, when it comes to weight loss, when you eat is not crucial. Where it does seem to make a difference is in how it influences appetite and the feeling of satiety. A larger breakfast seems to decrease the appetite hormones and increase satiety hormones, more so than when the largest meal is eaten at dinner time.

But what we already know is that, in nutrition, we have to aim for personal solutions: the metabolic response is going to be different from one person to the next, as is the rate of hormone production.

So if a person who has abundant dinners before going to bed is fine with it, there is no problem there. And if that person goes to the gym for two hours every day right before dinner, it means they are burning a significant amount of energy and need to compensate for it.

It has long been said that breakfast is the most important meal of the day. But breakfast literally means nothing more than breaking the fast. A hearty breakfast may work better for some people. We are seeing this with intermittent fasting in which the eating schedules are changed. Those general rules that we in the nutrition field had been recommending have become outdated. What we know now is that a study must be done on each individual person and, depending on their chronobiological rhythms, their schedules and how they feel emotionally, the nutritional recommendation should go one way or the other. It is something much more complex than adding and subtracting calories.

Other factors that play a big role are whether the individual is still physically growing, has a greater need for intake for some reason, and how their digestive process works. Simply asserting that it is bad to eat a large meal just before going to bed is harmful, and I believe that with our current knowledge in nutrition, it cannot be truthfully said.

María José Castro Alija is a medical doctor, nutrition expert and professor at the University of Valladolid in Spain. The general advice provided here is not meant to replace a visit to the doctor.

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