Does Eating Late At Night Make You Fat?
"Don't eat so late at night, you'll get fat!" If you have a habit of eating after "normal" dinner hours or right before you go to bed, then you've probably heard a variation of that phrase before.
We've all done it before - whether it's because you're starving after getting home late from work, or you're feeling the munchies after cramming for an exam past midnight. But it's probably not something you do often, because you don't exactly want to gain all that weight from nighttime eating.
Not only that, the idea that eating late at night contributes to weight gain is further perpetuated by the popular weight loss 'tip' that calls for no meals or no carbs after 6pm / 7pm / 8pm (depending on which weight loss article you're reading).
So, is it a scientifically-proven fact... or an old wives' tale that just won't die? Well, for a long time now, various studies and nutrition experts have actually debunked the notion as a stubborn myth.
The belief probably stemmed from a misguided understanding of how digestion works; that if you eat late and go to bed with a full tummy, your body's metabolism will slow down when you're sleeping, hence turning whatever you just ate into fat to be stored in your body.
Here's the thing - while it's true that the metabolic rate slows down during sleep, it doesn't mean that your body stops digesting the food in your stomach. Digestion still works as usual, albeit slower, so rest assured that the food you ate will not magically turn into fat while you're sleeping.
In its review of various clinical studies, the British Medical Journal concluded that there is no link between night-time eating and weight gain. The American Dietetic Association came to a similar conclusion, highlighting that it's not the timing of your meal, but the amount you're eating that is contributing to the supposed weight gain.
In fact, weight gain is not dependent on when you eat, but what you eat and how much you're eating
To quote nutrition expert Adam Bornstein, "Your body’s ability to gain weight is mainly about what you eat and how much, not when you eat." What really counts is whether or not you're burning off the calories you've ingested over time.
On that note, you'll also want to reflect on WHY you're eating late at night before you reach for the packet of Maggi or a can of Pringles. Are you eating because you skipped dinner, or simply because you're bored or feeling peckish? If it's the latter, be careful not to consume over your usual calorie intake (especially if you're munching on high-calorie foods like chips or pizza), because those extra calories will be turned into fat if they are more than you usually burn in a day.
Some studies also suggested that eating late at night or right before bed may even help you lose weight
In a 6-month study in 2012, researchers found that those who ate their largest meal after 8pm lost more body fat and had less hunger cravings compared to those who ate their largest meal during breakfast.
In a separate study by the Florida State University in 2015, researchers recorded a boost in metabolic function and improved blood pressure among respondents who consumed <150-calorie and protein-rich meals before going to bed.
On the other hand, a handful of studies have also found evidence to the contrary. Most recently, an experiment conducted by the University of Pennsylvania found that prolonged delayed eating could pose health risks in addition to weight gain.
In an experiment conducted on nine healthy weight adults, researchers from the Perelman School of Medicine found that prolonged delayed eating can increase weight, insulin and cholesterol levels, and negatively affect fat metabolism, and hormonal markers implicated in heart disease, diabetes and other health problems.
In its review of various studies on meal timing, Examine.com found that the scales are slightly tipped in favour of daytime eating, although some research proved that nighttime eating is not linked to weight gain or generated mixed and inconclusive results.
Most importantly, it also noted that research in this topic have yet to come to a definite conclusion when it comes to late night eating, as they are extremely heterogenous when it comes to the groups of people they study, the diets used, and other factors that may involve the respondents' lifestyle habits.
The bottom line is, eating at night most probably will not be the reason why you're gaining weight, as long as you watch what and how much you eat
In light of conflicting research findings as demonstrated above, it's also important to note that the impact of meal timing might be different for different people depending on their individual metabolic rate and lifestyle habits.
What we can say is this - it's all about striking a balance between how much you eat and how much of those calories you've burned off. No matter what and when you eat, your body will store extra calories that have not been burned off as fat. So if you find yourself reaching for a snack before bedtime, think first about how much you've eaten that day.