How much we eat is a factor of many different factors including how hungry we are, how palatable food is, how much ‘reward’ we get from food and social setting. The body has complex systems in place that, when functioning well, help ensure that we eat enough food but not too much. Some of this control is ‘endocrinological’ (hormonal) in nature: hunger and appetite can be influenced by hormones that either stimulate or suppress appetite. Hunger and food intake can be influence by our neurology too. For example, the stomach contains nerves that are sensitive to stretch. These nerves send signals to the brain that tell it, essentially, how much food there is in the stomach.
Some interesting research published this week suggests that the sensitivity of ‘stretch receptors’ in the stomach varies according to the time of day . Basically, at night, stretch receptors are more sensitive than during the day. In other words, during the evening and night, the stomach can feel fuller with the same amount of food had during the day. This mechanism would, in theory, help to moderate food intake before sleep.
There is a theory at least that this mechanism may help weight control. Research in animals shows that for a given number of calories, feeding at times during which the animals should be asleep can increase weight to a larger degree than if those calories are fed during wake-time. I not aware of similar evidence in humans, but the idea that excesses of food in the evening may be particularly ‘fattening’ is at least plausible. The fact that the body may put a natural brake on food intake in the evening may help.
However, I have to say, it seems many people seem to be well capable of over-riding this process. One of the most common cries I hear is of individuals saying that they eat ‘mountains of food’ late at night. Even though dinner may be imminent, some find themselves engaging in ‘fridge foraging’ or a ‘cupboard buffet’. Even after this, there can be a tendency for people to eat more than they feel they need, and perhaps not the best food either.
Time and again, people will express the opinion that they know this is not good for them, particularly when bedtime may be only a couple of hours away.
The cure for this phenomenon is usually quite simple, and requires individuals to be less hungry in the evening (for example when they return home from work). Some people have it their minds that ‘snacking’ between meals is to be avoided. I think if that ‘snack’ is a doughnut or half a pack of biscuits (cookies) then that’s probably true. However, the risk for some is that going from lunch to dinner without food can leave them utterly famished, inviting trouble.
In practical terms, the issue is usually easily dealt with by consuming a handful or two of nuts in the later afternoon and/or early evening. Coming home (or sitting in a restaurant) in a not particularly hungry state is what makes eating appropriate amounts of food in the evening much easier.
1. Kentish SJ, et al. Circadian Variation in Gastric Vagal Afferent Mechanosensitivity. The Journal of Neuroscience, December 2013