Eight is Too Late: Nighttime Calories May Pile on Pounds

Night Owl Image A recent study published in the medical journal, Obesity, revealed that night owls eat a higher percentage of their daily calories in the evening and are more likely to be overweight compared to adults who eat more of their calories before 8 p.m.

The study has been covered extensively on TV,  in newspapers and online, but most of the coverage focused on the findings that night owls eat more fast food, drink more soda and eat less fruits and veggies than those who go to bed and get up earlier.

What most reports failed to reveal, however, was the researchers’ finding that eating past 8:00 p.m. was an INDEPENDENT predictor of  body weight and was correlated with total daily energy consumption, regardless of what time subjects went to bed or how many hours they slept.

Don’t Fuel Up to Sleep

Our bodies don’t need fuel to sleep. We’re not vampires! Or bats! We’re humans and our circadian clock is set to eat during the day when we’re awake and most active.  Our p.m. noshing is driven more by habit than hunger.

Researchers at Northwestern University followed 52 adults who wore wrist monitors that tracked sleep and activity. Subjects also recorded all of their food intake and timing of meals and snacks over the 7-day study. Roughly half of the adults had normal sleep patterns while the other half stayed up late and woke up later.

The results found that night owls ate some 754 calories after 8 p.m. while the normal sleepers ate 376 calories during the same time. Unless you’re an endurance athlete, shift worker or plan to go out dancing all night, eating that many calories (376+) after 8 p.m. is too much for 99.9% of us.

Many obesity experts believe that a calorie is a calorie, regardless of when it’s eaten.  However, while this is a new area of research, this study and others suggest that daytime and nighttime calories are not metabolically the same.

Research shows that humans’ circadian rhythms that control sleep, eating and activity levels are normally synchronized so we don’t eat nocturnally. Eating at night may cause disruptions in hormones that regulate appetite and hunger, making it harder to lose and maintain a healthy weight.  In fact, studies show that rodents get fatter when they’re fed at times when they’d normally be at rest and even feeding animals at different light-dark cycles results in weight gain. Night eaters may also be distracted when munching and crunching and this too may cause overeating, and the foods readily available (and most appealing) may not be the healthiest.

Beat the Diet Bewitching HourBlue Moon Photo

I’m not a night person and I’m even less of a nighttime eater. After dinner  I’ll have water and/or tea while watching SportsCenter or Top Gear, but I rarely eat.  It took some time to develop this healthier habit, but once I did, I never even think about my old favorite moon-time munchies.

If you’re struggling to lose or maintain a healthy weight, try not eating after dinner and see if it helps. If you’re extremely hungry, plan a light p.m. snack of up to 200 calories but make it something that’s nutritious and filling like handful of nuts with a cup of  tea; half of a PB& J on whole wheat; whole grain crackers with some low-fat cheese; half a cup of yogurt or cottage cheese with dried fruit or a piece of fresh fruit.




  1. Logan says

    I don’t know if I’m considered an “endurance athlete,” but I swim for about 90 minutes at 11am and cycle 60 minutes in the evening before dinner. I eat 3 meals a day, breakfast is ususally oats, nuts, protein, milk, fruits, and a veggie. Lunch is usually brown rice, some lean protein, olive oil, veggies, and fruit. Both those meals are about 800 calories. I need around 3000 cals a day, and my dinner is usually 1500 calories. I eat it late at night at about 930pm, and go to bed at 1030pm. I have the same thing for dinner usually too. 4 or 5 Pancakes with 6-7 tablespoons of peanut butter and syrup. The batter is 3/4 cup flour, 1/4 cup whey protein, 1 greek yogurt, 1/2 cup milk, 2 eggs, and baking powder. This has always worked for me, and my weight and sleep haven’t been affected by it. I’m also young, so I don’t know how much that has to do with it. But do you think I should change my habits?

  2. says


    You’re clearly really active and this study looked at middle-aged primarily sedentary Americans so I don’t think we can apply these findings to
    your habits. As dietitians, we’d like to see a higher percentage of your daily calories earlier in the day just because it helps to provide more energy when
    we’re most active.

    If you don’t have weight issues and you have good energy during the day, probably no need to change the way you eat. BTW, you might want to consider some other dinners that include veggies, salad, cooked fish/poultry/lean meats…instead of pancakes….Just a thought


  3. says

    The main question here is: Are people who are eating that many calories after 8:00 PM eating more overall calories in a day’s time than their body needs? If so, it’s a no-brainer that they will be gaining weight. Granted, after 8:00 PM, many of those eaten calories are going to be stored rather than immediately used. But, if the next day the amount of calories eaten before 8:00 PM added to those eaten after 8:00 PM equal what your body uses and you burn off with activity or exercise, then becoming overweight shouldn’t be an issue. This study seems to be pointing to the body not being able to retrieve stored calories efficiently the next day. That I’d like to see further research on to corroborate the study’s results.

    The other question I would have is when are these people who are eating so many calories after 8:00 PM eating their dinner? If at 6:00 or 7:00 PM, why so many calories after 8:00 PM if the dinner was healthy and adequate in calories? Now we’re back to habits rather than hunger. How many people only eat when they’re truly hungry versus how many people eat because of the time of day, who they’re with, what they’re doing, etc.?

    Bottom line: Listen to your body talk and stop listening to your head talking.

  4. says

    I remember a supplement years ago called Calorad (just looked it up and it’s still out there – people still buy this stuff?!). It’s a collagen/aloe vera magic potion that will miraculously help people lose weight. Directions are to consume a serving 3 hours before going to bed and – EAT NOTHING AFTER TAKING IT. Helloooo…is it no wonder weight loss results? Consider a night snacker consuming hundreds of calories between dinner and bedtime and then stops. Of course weight loss will occur. Nothing to do with the supp but of course that gets the credit – by the people gullible enough to believe it. Oye!

  5. says

    Thanks for the response J,

    I agree that I should be getting more cals in the beginning of the day, but the reason I choose to have such a large and late dinner is because I like the tank to be completely full for my 6am swim.

    Also, I still get in my fruits, veggies, and meats haha! I have fruits and veggies in every meals, and for lunch I always have some kind of lean meat such as fish, chicken, or tofu with my pasta or rice. I just moved into an apartment a couple months ago from the dorms, so I have made 60 new pancake recipes in the last 60 days. I’am hooked.

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