How often have you heard that you shouldn’t eat carbs after 6 PM or you shouldn’t eat right before bed for fear that all of the food you just ate will turn to fat?
The "logic" behind these sayings basically stems from the belief that the body would have no immediate need for those calories and store them as fat since you go to bed (and therefore do not participate in any demanding physical activity).
But, here's the thing, just because you do not engage in a high-rep leg exercise or go for a jog, doesn't mean that when you're sleeping, your body doesn't function (and thus burn calories).
In fact, when we sleep, the body is fairly active from a metabolic point of view, as it is when we sleep that the body does its greatest amount of repair and growth.
In addition, let's imagine that you work long hours and have no time to eat all your meals during the day, and the only time you can eat is an hour or two right before bedtime. Are all these calories going to go straight to fat storage, even though your calorie needs for the day are not exceeded?
Some “gurus” will say that they will…
...and they would be 100% wrong.
You see, the physiology of humans is not so sensitive. It's not like there's a magical clock within our bodies that says, "Oh no, it's after X P.M. All these calories are going to be stored as fat."
The human body doesn’t work that way.
As long as you have not met your calorie limit for the day, if you eat right before bed, you will not get fat.
In other words, if you eat all your calories right before bed (intermittent fasting) in a 2-4 hour span or spread them uniformly over the course of a day, if you remain within your limits, you will not gain body fat.
That being said, it can make it harder to sleep for certain people to eat large quantities of food shortly before bedtime. However, some individuals find that when they have a full belly, they actually sleep better (especially if they consume a lot of carbs before bed, as carbohydrates stimulate serotonin production, which enhances mood, relaxation, and sleep).
If they appear to overeat on snacks and surpass their calorie limit for the day, the only valid reason why a person should stop eating before bed is.
What induces fat gain is these extra calories above your TDEE, not the fact that you ate them late in the night.
Take Home Message
When you eat more calories than your body needs for an extended period of time, fat gain occurs. It doesn't just happen when you feed right before you go to bed.
Keep in mind, weight gain is a function of calories versus calories. You can split your calories however you prefer, as long as you do not reach the calorie limit for the day (whether it be evenly across the day or within the final few hours before bed).
If you are prone to mindlessly snacking at night, which would cause you to overeat, the only time it makes sense to stop eating right before bed is.