If you’ve ever tried to diet or lose body fat, you’ve probably read, or had someone tell you, that you shouldn’t eat (especially carbs) after 6pm, and definitely not just before bed! The argument often follows that your metabolism slows down while you are sleeping, so that anything you eat too late at night will simply be stored as fat… we can say definitively that this is not how it works.
The belief and support from this myth stems from the fact that some people who follow this rule do, in fact, lose weight. They cut out carbs, or food altogether, after a certain time at night, their weight loss plateau ends and they begin to see the progress they want! Now, we don’t want to denigrate the achievements of anyone who has managed to lose weight or improve their health and wellbeing, but what we need to clarify here is why this method works.
For many people, the time of day when they are most likely to snack on high-calorie foods and eat mindlessly is the end of the day. After dinner they may go looking for something sweet, or sit down in front of the TV and snack continuously as they watch their favourite programme. Merely by adding in the rule to not eat anything after a certain time can mean that they cut out this late night snacking and calorie consumption… by cutting out these calories, it’s no wonder that this strategy works well for their weight loss goals.
However, studies have shown a fat-loss advantage for both early eaters (not eating after a certain time) and late eaters (not eating before a certain time). Why is this the case? Well, because both strategies narrow your ‘eating window’. So long as the window we impose upon ourselves lines up with our preferences and when we are most likely to overeat, then it’s going to be a successful strategy in moderating our calorie intake.
Ultimately, eating late at night will only lead to weight gain if it causes you to consume more calories. While it can be a successful strategy to stop eating after a certain time for some, for others it could have a detrimental effect if it causes you to therefore overeat during another part of the day.
Most dieting strategies can work, but we always need to be aware of the mechanisms behind why they work. Remember, weight or fat loss always comes down to energy balance, so we need to understand why a certain way of eating may or may not affect your calories in vs calories out!