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Will Your Late Night Snacks Keep You From Losing Fat?

Avatar Nutrition Staff

March 28, 2018


Are you crazy? You can’t eat before bed if you want to get lean!

Many gym goers proudly boast they don’t eat carbs at night. And, if you listen to most “fitness gurus,” you’ll probably think that all calories eaten after 6 pm (that magical number) will turn directly into fat. It’s as if your body can somehow tell time and that once the clock strikes six it is time to dispose of food differently than it did at 5:59.

But is this true? Does your body treat food differently after a certain time, or while you sleep?


Where Does This Idea Come From?

If you read those questions and started passionately nodding “yes!” it’s probably because you’ve heard that your metabolism cranks to a halt while you sleep. If shutting your eyes instantly shuts down your calorie burn, then it would make sense that late-night snacks would be more likely to store as fat.

However, research has challenged this assumption by showing that, while energy expenditure decreases during the first half of sleep, it increases again with REM sleep [1,2]. It makes sense: during REM sleep, your breathing becomes more rapid and irregular, your heart beats faster, and your blood pressure increases. Almost like you’re performing light exercise!

Due to the rises and falls in sleeping metabolic rate there doesn’t seem to be much difference between your sleeping energy expenditure and your basal metabolic rate during the day [3,4]. This is good news, because it means there’s no logical reason that your body’s normal metabolism of food will change either! Additionally, exercising (like prolonged cardio) increases sleeping metabolic rate, which can lead to more fat burn [5]. So, if you’re even a little worried that hitting the pillow will hit your metabolism, getting out there and exercising will help!


Carbs Before Bed

Eating before bed isn’t going to wreck your goals. But, when it comes to choosing which foods to eat before going to sleep, are all calories created equal? Are some macros better than others?

Nothing gets demonized as a sleepy-time fat-builder more than carbs. In fact, most of the warnings against eating before bed are directed at avoiding carbohydrates, usually with the cut-off somewhere around 6 pm.

But the science just doesn’t agree. In fact, some weight-loss studies have shown that eating the majority of your carbs later in the day can result in losing more weight and body fat, as well as feeling less hunger while dieting [6]. Another study found that eating the largest meal of the day in the evening may not accelerate weight loss, but it can help maintain muscle mass [7].

While it probably doesn’t matter that much whether you eat most of your carbs early or late in the day, it certainly isn’t true that you can’t eat them right before bed. In fact, you could make a case (based on the studies above) that it’s beneficial to save your carbs for later! That said, if you care enough to focus on carb-timing, it’s probably best to eat most of them around your workouts [10].

(And you should also check out our pre-workout and post-workout nutrition guides!)


Protein Before Bed

Now that we’ve covered why you shouldn’t worry too much about carbs, let’s talk about protein. If you, like many people, struggle to hit your protein target by the end of the day, it would be extra hard to restrict yourself from eating it late at night. Luckily, pre-bed protein is another example of how “back-loading” your food could be a great move.

For example, many sports nutritionists suggest that eating casein protein (one of the two proteins found in dairy products) can be beneficial for muscle growth and maintenance. Casein—as opposed to whey, the more popular protein choice—is special because it digests very slowly, creating a “sustained release” of amino acids over several hours. By taking advantage of casein’s prolonged effects in the gut, you could be spending your sleeping hours effectively building muscle [8].

Taking casein before bed could also help keep you feeling full the morning after [9]. If you’re deep in a diet, you’re probably used to waking up feeling hungry. Not only could taking some casein the night before help you hit your protein target—you could also feel less hungry when you wake up. This can help some dieters stick to their macros and make more progress in the long run.


What Does It All Mean?

In terms of improving body composition, what and when you eat is insignificant compared to how much you’re eating. Instead of focusing on the timing of your meals, focus on hitting your overall macros each day. Having a meal late at night isn’t any worse than eating at any other point during the day, and as we’ve seen, may even have some important benefits!

The takeaway here is: eat how you want, and control how much you eat. If you feel that eating late at night helps you reach your goals, there’s no science that would hold you back! If you don’t like eating before bed, that’s fine too. Once again, science tells us we’re free to be flexible and attack our goals as we choose!




1. Katayose Y, Tasaki M, Ogata H, et al. Metabolic rate and fuel utilization during sleep assessed by whole-body indirect calorimetry. Metabolism. 2009 Jul;58(7):920-6.
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