Will I Get Fat if I Eat at Night?

How many times have you asked this question? How many times have I been asked this question? Too many times to count.

So let’s straighten this out for you once and for all.

You will NOT gain weight if you eat after 8 pm unless you have eaten more calories than you body has used (or unless you have a medical condition that has been diagnosed by your doctor).

Let me explain the concept of energy balance – energy, in this case, meaning calories. Weight is a balance of intake and expenditure. Intake means the number of calories you consume; expenditure is the number of calories your body uses. When intake is greater than expenditure, you gain weight. When intake is less than expenditure, you lose weight. When intake equals expenditure, your weight should stay the same.

Of course there are a number of factors that can affect this somewhat simple view of weight control, but for the average person, the math is simple. Calories in versus calories out.

But let's look at what ELSE happens when you eat after 8pm (or 7pm, or 6 pm – depending on which diet book you have recently read). If you are eating later in the evening, chances are you won't be hungry when you get up the next morning. What happens then? You probably skip breakfast. And thus begins a downward spiral leading to overeating, feeling lousy, and gaining weight.

Included in that spiral are events that affect you physically and mentally. Physically, your metabolism, the rate at which your body burns calories, slows down. As I have said before, when you skip a meal, you body doesn't know if this “fast” is voluntary or involuntary. It will act to conserve every calorie it gets by slowing down the rate at which you burn calories. So in effect, your attempt to skip the meal to “make up” for the extra calories you may have eaten last night only serves to sabotage you.

Psychologically, you set yourself up to overeat later. If you skip breakfast, you will eventually get hungry. Chances are that you will, on a subconscious level, say “well, I didn't eat breakfast, so it's all right to potato chips with my sandwich,” or “I haven't eaten all day so I really don't have to worry about how much I eat for dinner.” In the end, you wind up consuming more calories than if you had simply had a small breakfast of, say, a piece of toast and peanut butter, or a small bowl of cereal.

Yes, there are a few risks associated with eating later at night, especially if you go to bed shortly after eating. But they aren't related to weight gain. One is developing reflux, more commonly known as heartburn. See, your digestive system (starting with your mouth, down your throat, through the stomach and so one until…the end) works better WITH gravity. If you eat a big meal and then lie down, you're still digesting food, but now your body is lying flat, making if more difficult for food to move down the digestive tract. Oh, it will get where it needs to go, but in the mean time, it may wear down some of the tissue of your upper digestive tract and cause you to develop heartburn.

When I was growing up, we always had dinner at 6 pm (just don't ask my children about regular eating times, OK?). Right after dinner, Dad would lie down on the couch, watch the news and take a short nap. Years later, he developed a strong case of reflux, and it wasn’t because he ate late and went to bed early; it was because he would lie down right after a meal. The recommendation is to wait at LEAST two hours after a meal before lying down to reduce your risk of developing reflux.

So, will you gain weight from eating after 8 pm? While I can't make you any promises, (and barring any unusual medical conditions), I can tell you that as long as you eat the same or fewer calories than your body uses, you won't gain weight. Just remember, if you do eat later in the day, don't lie down for a few hours.

Hey, maybe this would be a good time for a short walk?

Become At Peace with Food: Stop Dieting and Lose Weight

NOTE: Information in this site should not replace any medical advice you have
received from your primary care doctor or other medical professionals.