Well, depends on what you eat

Will Eating Late at Night Make You Fat?

By SHAPE magazine | Healthy Living – Mon, Aug 5, 2013 9:19 PM PHT
by Keri Gans, R.D.N., for SHAPE.com 

Can your late-night snacking habit pack on the pounds?Last week, I co-hosted a twitter chat for Shape.com. There were so many great questions, but one particularly stood out because more than one participant asked it: "How bad is it to eat after 6 p.m. (or 8 p.m.) for weight loss?" 

I love this question. Truthfully, my patients ask it all the time. And my answer is almost always the same: "Eating late at night doesn't cause you to gain weight, but eating too much late at night will." 

Let's review: If your body needs 1,800 calories to maintain a healthy body weight and you ate only 900 calories by the time it was 9 p.m., you could in reality eat another 900 before bedtime. The problem is the longer it gets until dinnertime, the hungrier you get, and for most people the chances they will overeat increases. So what ends up happening is excess calories are consumed. I sometime explain this as the "domino effect." You've waited so long to eat that by the time you do, you can't stop. 

RELATED: 11 Nutrition Myths That Cause Weight Gain 
But what should you do if you eat a well-balanced dinner at a reasonable hour and you are still hungry before bedtime? First off I usually recommend trying to figure out if you are really hungry. I like to use the acronym HALT. Ask yourself, "Am I hungry? Am I angry? Am I lonely? Or Am I tired?" So many of the times we eat at night have nothing to do with actual hunger. Once you identify what is really going on, you might be able to prevent late-night munchies. 

Now if you really are hungry, I usually suggest a late-night snack of around 100 calories or less. For example: a piece of fruit or cup of berries, three cups of air-popped popcorn, a sugar-free Popsicle, a single serving of low-fat pudding, a glass of nonfat milk, raw veggies, or a six-ounce container of nonfat fruit-flavored yogurt. 

One of the main reasons to eat earlier in my opinion is because you will sleep better. Going to bed on a full stomach for many people is a detriment and interferes with their beauty rest. And unfortunately if you don't sleep well, there is an increased chance that in the morning when you are exhausted you will make poor breakfast decisions. But the best solution of all is to go to bed earlier-you can't eat when you are sleeping. 
source: http://ph.she.yahoo.com/blogs/healthy-living/eating-night-fat-131900849.html