The idea that eating late at night causes weight gain has long been a source of interest and debate. Most nutrition experts have felt that this is not necessarily true. The common teaching is that if people eat more than they expend, then they will gain weight – regardless of whether the calories come from breakfast, dinner, or a late night snack. However, there have been few high quality studies to confirm that calories eaten at night are metabolized the same as calories eaten during the day. In fact, an experimental study last year found that mice who ate the majority of calories during their typical sleeping hours did gain more weight than mice that ate on a more regular schedule, despite consuming the same number of calories and engaging in equal amounts of physical activity. However, as we all know, results from a study in mice cannot be directly extrapolated to humans. Those human studies are still yet to be done.
Of course, another explanation for why late-night eaters may tend to put on more weight than people who rarely eat after a certain time, such as 8pm, may be that people who eat a lot of food late at night consume more calorie-dense foods and thus eat more total calories which can cause weight gain. It’s probably not when you eat that’s the problem, but rather what and how much. If you find yourself mindlessly eating chips at 10:00 at night while watching TV, then it might be helpful to reverse this fat-promoting behavior by making a behavioral plan which may include not eating after 8:00pm. Or, you could try any number of the following tips to help train your mind and body to be mindful of your food intake and eat when you’re hungry and stop before you’re too full.
- Avoid tempting situations. If you struggle to break the habit of nibbling on junk food late at night, make a plan to decrease availability of those foods. For example, keep the junk food out of the pantry and stock up on fruits and vegetables. Eat small, well-planned meals throughout the day to help avoid a starvation binge late at night. To reduce psychological cues to eat (such as boredom, habit, stress, etc) restrict eating to the kitchen or dining room table.
- Self monitor. One of the strongest predictors of successful and maintained lifestyle change is monitoring dietary intake. While it can be tedious to keep a daily food log, this practice is highly effective. For one week maintain a detailed food log listing the type and amount of food eaten complete with calories, time of intake, hunger ratings, emotions, and activities at the time of eating. Also record the types and amounts of physical activity. Choose one representative day and assess your dietary and exercise quality at www.mypyramidtracker.gov. Do you find that most of your calories come after dinnertime? What kinds of cues trigger you to eat, even when you’re not hungry?
- Set SMART goals. SMART (specific, measurable, attainable, relevant, and time-bound) nutrition and physical activity goals help set the stage for weight loss success by transforming vague visions of thinness into a specific plan for a healthier lifestyle. Here’s just one example of a SMART goal: “I would like to lose five pounds in the next two months. I will do this by eliminating post-dinner snacks, avoiding eating while watching TV, and exercising for 30 minutes five days per week.” Post visible reminders of the weight, dietary, or fitness goal to help make achieving the goals a reality.
- Practice behavioral substitution. Many people turn to food when bored or stressed. Before raiding the refrigerator or pantry, ask why you are eating. If it is for any reason other than hunger, vow to substitute alternative behaviors to eating. For example, if you eat when you’re bored, take a 10 minute walk instead.
- Retrain your brain – and taste buds. Commit to eating a healthy, well-balanced diet which includes portion-controlled servings of a few of your favorite foods. This way the deprivation and cravings are minimized, and you might be shocked to find that after a while, the fat- and sugar-filled foods which were once so desirable lose much of their allure.
Natalie Digate Muth, MD, MPH, RD, is a registered dietitian and recent graduate of the UNC School of Medicine. She is an ACE-certified Personal Trainer and Group Fitness Instructor, and holds additional certifications with the American College of Sports Medicine and the National Strength and Conditioning Association. She has made several appearances as a nutrition expert on CW's San Diego 6, been quoted as a fitness expert in the New York Times and other newspapers and is an ACE Master Trainer and award-winning author. She is currently a pediatrics intern at UCLA Mattel Children’s Hospital.