Can late-night eating make you gain weight? The short answer: It’s complicated.
While the occasional late-night snack won’t necessarily add inches to your waistline, consistently eating later in the day can disrupt your body’s natural rhythms. These disruptions can lead to poor sleep, increased cravings, and changes in metabolism. When combined, these changes can promote weight gain over time.
What the Research Says
“There is strong evidence that eating late at night can increase your risk of weight gain,” says Richele Corrado, DO, a board-certified obesity and internal medicine physician at Revolution Medicine, Health & Fitness, a medical weight loss, fitness, and nutrition practice in Washington, DC.
A systematic review of 10 studies involving 6,401 participants found consistent links between later eating patterns and higher body weight. In addition, a study of more than 3,300 people showed that those in the late-night dinner group had a higher risk of obesity despite similar calorie intake and physical activity levels as earlier dinner eaters.
These findings suggest that the timing of meals and snacks may be of similar importance as overall energy balance, and that eating earlier may be a useful strategy for weight management.
5 Ways Late-Night Eating Can Impact Weight
Meal timing affects multiple systems in the body that are closely connected with metabolism, appetite, and overall energy balance. Eating late can impact these systems in ways that contribute to weight gain.
1. Late-Night Eating Impacts Sleep
Eating close to bedtime may cause gastrointestinal (GI) discomfort, heartburn, and acid reflux, leading to sleep disruption. Indeed, eating a meal within three hours of bedtime may increase nighttime awakenings by up to 60 percent, according to research in young adults.
This sleep disruption can fuel weight gain by interfering with appetite-regulating hormones, leading to increased hunger and cravings the next day.
Late-night eating can also interfere with sleep. “Your body has a natural daily clock, called your circadian rhythm, and eating late goes against this rhythm,” says Dr. Corrado. This can affect the hormones involved in sleep and metabolism. Even if you fall asleep without trouble and don’t notice obvious symptoms, your sleep may be lighter or more fragmented, meaning your body isn’t fully resting or recovering overnight.
2. Late-Night Food Choices Tend to Be Poor
Research shows that people tend to satisfy late-night cravings with foods higher in fat, sugar, salt, and calories, rather than nutrient-dense options like fruits, vegetables, lean protein, and low-fat dairy. This isn’t poor willpower — our circadian rhythm naturally increases hunger and appetite in the evening, making us especially drawn to calorie-dense foods.
This may once have been an evolutionary advantage, as high-calorie, high-fat foods may have helped sustain our ancestors through periods of food scarcity, researchers note. Today, however, regularly consuming these extra calories (whether in the form of a meal or snack) right before sleep can contribute to weight gain over time.
3. Late-Night Eating May Increase Overall Calorie Intake
Research reveals that adults who eat a meal or snack after 8 p.m. consume an average of 300 more calories per day than those who stop eating earlier. Moreover, these extra calories typically come from salty snacks and sweets.
“If late-night eating is in addition to normal levels of food intake during the day, this can lead to a surplus of calories, resulting in weight gain,” says Jeff Stanley, MD, a board-certified internal medicine physician, and the medical director of Virta Health, a virtual clinic specializing in weight loss and metabolic health.
4. Late-Night Eating Affects Blood Sugar Control
Eating close to bedtime can disrupt overnight blood sugar control. One study found that eating dinner at 10 p.m. instead of 6 p.m. caused an 18 percent higher peak blood glucose that persisted for four hours. Late dinner participants also had elevated glucose and insulin (the hormone responsible for regulating blood sugar) levels the following morning after breakfast meals than earlier eaters.
These blood sugar spikes matter because elevated glucose triggers the release of insulin. Higher insulin levels also promote fat storage. Over time, repeated late-night eating with these blood sugar fluctuations may contribute to obesity and metabolic disease.
“Late-night eating, particularly with foods high in sugar or processed carbohydrates, increases insulin levels,” says Dr. Stanley. “One of the functions of insulin is fat storage, so elevated levels can lead to insulin resistance and obesity,” he adds.
5. Late-Night Eating Affects Metabolism
Research shows that eating late at night disrupts multiple metabolic processes in ways that may promote weight gain.
In one study of 16 participants, eating dinner later altered appetite-regulating hormones in ways that increased hunger throughout the day. At the same time, late eaters burned approximately 5 percent fewer calories daily compared with early eaters.
The study also found that late eating changed the expression of genes involved in fat metabolism, shifting the body from fat burning to fat storage mode. Together, these metabolic changes may lead to weight gain.
“Studies show that late-night meals can make you feel hungrier, slow down how many calories your body burns, and throw off your metabolism, or how your body uses food for energy,” Corrado explains. In fact, your body burns fewer calories digesting the same meal late at night than it does earlier in the day, she says.
Should You Worry About Weight Gain From Eating Late at Night?
“Eating late at night once in a while is not likely to cause weight gain,” Corrado says. “It becomes more of a problem when it happens many times per week, especially if the late-night snacks are high-calorie ‘junk’ foods that can raise blood sugar and alter hunger hormones,” she adds.
If you do eat late at night, choosing nutritious options can make a difference. Foods like chicken, nuts, fish, whole grains, fruits, vegetables, and dairy provide important nutrients like protein, vitamins, minerals, and fiber while keeping calories and fat in check. This may reduce the likelihood of late-night meals and snacks leading to weight gain.
Timing matters, too. Having your last meal or snack two to three hours before bed may help minimize the metabolic effects of late-night eating, Corrado says. If you’re trying to lose weight specifically, shifting meals and snacks to an earlier timeframe may further support better appetite regulation, metabolism, and overall weight management.
As a general rule, avoiding late-night eating — especially unhealthy, calorically dense processed foods and sweets — helps weight loss efforts, Stanley says.
5 Tips to Avoid Weight Gain if You Eat Later
Sometimes, late-night eating is unavoidable due to busy schedules or other commitments. Experts share their top tips for reducing the risk of weight gain when eating late is necessary. But be sure to consult a registered dietitian for personalized guidance.
Here are a few ways to avoid weight gain from late-night eating.
Eat two to three hours before bed. There isn’t one ideal time to have your last meal. But Corrado says it’s best to finish eating at least two to three hours before your planned bedtime. This allows your body time to start the digestion process, reducing the risk of heartburn and other digestive upset that may impact your sleep, she explains.
Be mindful of portion sizes. Eating large portions of food late at night may lead to weight gain since this is when our metabolism naturally slows to prepare for sleep. Corrado suggests eating a bigger breakfast and lunch, and making dinner your smallest meal of the day.
Choose nutrient-dense foods. Late-night eats shouldn’t be a free-for-all. “Choose nutrient-dense foods that are higher in protein and fiber and lower in simple carbs that can spike blood sugar,” says Corrado. Nutrient-dense options include whole foods like fruits, veggies, whole grains, lean or plant-based proteins, and dairy. These options provide protein, fiber, and complex carbohydrates to keep you full without overdoing calories late at night.
Practice mindful eating. Sometimes, we eat for emotional reasons (such as stress, loneliness, or boredom) rather than physical hunger. Other times, we rush through meals without tasting them. Both can lead to overeating and weight gain. Before eating, ask yourself: Am I actually hungry? “If the urge to eat comes from emotions, it’s important to notice that and start thinking about other things you might do in the future to handle those feelings without turning to food,” Corrado says. If you are truly hungry, eat mindfully: Slow down, savor each bite, and pay attention to flavors and textures.
Eat balanced meals throughout the day. “One of the best ways to reduce late-night eating is to make sure you eat enough earlier in the day so your hunger hormones stay balanced,” Corrado says. So, don’t skip meals, and be sure to include protein and fiber to keep you satisfied.
The Takeaway
Late-night eating can lead to weight gain by affecting sleep, blood sugar control, and metabolism, and increasing overall daily caloric intake.
Experts recommend eating your last meal or snack at least two to three hours before bed.
Choosing nutrient-dense foods in reasonable portions when eating late at night can help reduce the likelihood of weight gain.
EDITORIAL SOURCES
Everyday Health follows strict sourcing guidelines to ensure the accuracy of its content, outlined in our editorial policy. We use only trustworthy sources, including peer-reviewed studies, board-certified medical experts, patients with lived experience, and information from top institutions.
Resources
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Iao S et al. Late Meals, Sleep Duration, and Sleep Fragmentation: Findings From the American Time Use Survey. Sleep. April 2020.
Baron KG et al. Role of Sleep Timing in Caloric Intake and BMI. Obesity. September 10, 2012.
Scheer FA et al. The Internal Circadian Clock Increases Hunger and Appetite in the Evening Independent of Food Intake and Other Behaviors. Obesity. March 2013.
Sebastian RS et al. Late Evening Food and Beverage Consumption by Adults in the U.S. What We Eat in America, NHANES 2013-2016. United States Department of Agriculture. 2010.
Insulin and Weight Gain: Keep the Pounds Off. Mayo Clinic. September 1, 2022.
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Sean Hashmi, MD, is an experienced nephrologist and obesity medicine specialist based in Southern California. As the regional director for clinical nutrition and weight management at a prominent healthcare organization in Southern California, Dr. Hashmi oversees the development and implementation of cutting-edge nutritional programs and weight management strategies. With his innovative approach and unwavering commitment to providing evidence-based solutions, he is a highly sought-after speaker and a leader in his field.
Hashmi founded the nonprofit organization SelfPrinciple.org to provide accessible and accurate health, nutrition, and wellness information to the public. Through this platform, he shares the latest research findings, empowering individuals to make informed decisions about their well-being. Self Principle also supports children's education by providing scholarships, books, and supplies, so that students have the resources necessary to succeed academically and build a brighter future.
Katie Drakeford, MA, RD, LD, is registered dietitian with over 14 years of experience working with people of all ages to improve their health through nutrition. She also holds a board certification in pediatric nutrition and is a certified lactation counselor. She also serves as a subject matter expert in pediatric nutrition for the Academy of Nutrition and Dietetics.
Katie enjoys sharing health and wellness content that is evidence-based, actionable, and helps people reach their health goals. She writes for multiple outlets including Parents, Yahoo, Parade, and more. She has also been featured in dozens of media outlets as an expert contributor in the nutrition space.
