Eating at night has long been associated with weight gain. Years ago, nutrition pioneer Adele Davis gave her well-known advice to “eat breakfast like a king, lunch like a prince and dinner like a pauper.”
Yet the conventional wisdom today is that a calorie is a calorie, regardless of when you eat it, and that what causes weight gain is simply eating more calories than you burn. Nutrition experts call this the calorie in/calorie out theory of weight control.
According to the U.S. Department of Agriculture’s Weight Control Information Network web site, “it does not matter what time of day you eat. It is what and how much you eat and how much physical activity you do during the whole day that determines whether you gain, lose, or maintain your weight.”
A study in the journal Obesity added to the confusion by suggesting that there may be more to nighttime eating than just overeating calories. Northwestern University researchers found that eating at night led to twice as much weight gain -- even when total calories consumed were the same. But this research was done on mice, not humans, and the reason for the weight gain is unknown. And a single mouse study should not cause us to toss out the wealth of evidence supporting the calorie in/calorie out theory.
Still, there are good reasons to be cautious about eating at night. Diet books, dietitians, and even Oprah recommend not eating after dinner (other than a small, calorie controlled snack) because it’s just so easy to overdo it.
People eat at night for a variety of reasons that often have little to do with hunger, from satisfying cravings to coping with boredom or stress. And after-dinner snacks tend not to be controlled. They often consist of large portions of high-calorie foods (like chips, cookies, candy), eaten while sitting in front of the television or computer. In this situation, it’s all too easy to consume the entire bag, carton, or container before you realize it. Besides those unnecessary extra calories, eating too close to bedtime can cause indigestion and sleeping problems.
(This type of nighttime eating is not to be confused with the medical condition “night eating syndrome,” which requires professional medical attention.)
There’s nothing wrong with eating a light, healthy snack after dinner as long as you plan for it as part of your daily calories. To keep from overeating, pay attention to your food while eating, avoid eating in front of the TV, and choose a portion-controlled snack. Some good options are packaged 100 calorie snacks, small servings of popcorn, ice cream bars, low-fat yogurt or fruit.
When you’re trying to lose weight, eat regular meals and consume 90% of your calories before 8 p.m. The benefit of eating meals every three to four hours is it helps regulate your blood sugar, and thus control hunger and cravings.
The bottom line: More research is needed on humans to determine whether calories eaten at night are more likely to cause weight gain than those eaten early in the day.
Kathleen Zelman, MPH, RD, is director of nutrition for WebMD. Her opinions and conclusions are her own.