There's an old saying about healthy eating: "Breakfast like a king, lunch like a prince and supper like a pauper." In other words, front-load your calories in the early part of the day. But does that mean you should be skipping dinner if you want to lose weight?
The short answer: Not necessarily.
In fact, recent research actually suggests the exact opposite: skipping dinner might encourage weight gain.
In a January 2021 Nutrients study, researchers found that college-aged students who regularly skipped dinner gained more weight than their counterparts who — for the most part — ate dinner daily. Dinner-skippers gained about 10 percent of their body weight over the six-year study period and were also more likely to be in the overweight/obese body mass index (BMI) category. These findings were consistent in both people assigned male at birth and people assigned female at birth.
Why Skipping Dinner Might Cause Weight Gain
"People who skip dinner still eat throughout the evening, they just tend to eat more snack-like foods and nibble, which is what would lead to weight gain," says Amanda Nighbert, RD, who specializes in weight loss nutrition. "From my experience, [dinner-skippers] most likely load up on snacks that tend to lack nutrition, are low in fiber and protein, and high in sugar and carbs. These types of food rarely fill you up and can lead to eating more."
In the Nutrients study, researchers also looked at people who initially were dinner-skippers and "reformed" themselves into regular dinner-eaters and compared them to people who stuck to their habit of skipping dinner more often. Turns out, people assigned male at birth who were perpetual dinner-skippers weighed the most (as in, more than the "reformed" dinner-skippers and more than the regular dinner-eaters). The findings among people assigned female at birth weren't significant enough to say either way.
"Those who sit down to dinner typically consume healthier foods and a more balanced meal," says Nighbert. "[Dinner-eaters] tend to eat more vegetables and protein at meal times — and they tend to fill up on healthy foods, therefore reducing the need for late-night snacking."
Still, there's other research that indicates skipping dinner could encourage weight loss. For instance, a study of about 50,000 people in the September 2017 issue of The Journal of Nutrition found that people who ate fewer than three meals a day and took the longest overnight break between meals lowered their BMI significantly over the course of a year.
Even skimping on dinner made a difference: In the same study, people who made lunch or breakfast their largest meal of the day lowered their BMI more so than people who had their biggest meal at dinner.
The Best Way to Skip Dinner to Lose Weight
Skipping dinner seems to work in the above study because participants were essentially intermittent fasting versus forgoing dinner and then having a snackfest later in the evening.
"When people implement intermittent fasting, skipping dinner can be a powerful weight-loss tool," says Nighbert. She says this type of fasting is called circadian rhythm fasting and mimics our traditional eating patterns.
"The goal is to eat when the sun comes up and finish eating when the sun goes down. Eating in line with your circadian rhythms can make for better weight management, as well as improved sleep, healthier blood sugar levels and more," Nighbert says.
Researchers think eating at the wrong times of day, and specifically too late at night, hinders our health because of higher levels of glucose and insulin late at night.
"When we eat a large meal late, this triggers digestion and a large amount of glucose in the bloodstream. Our bodies actually prefer to burn stored fat at night versus breaking down glucose," says Nighbert.
This imbalance affects sleep quality and energy levels, and ultimately throws off your circadian rhythm. That's why Nighbert recommends wrapping up your last meal at least three hours before bedtime.
4 Tips for Healthy Intermittent Fasting
When you narrow your eating window during the day, you need to make sure the meals you are eating are meeting your nutritional needs.
- Don't let your overall calories drop too low — that means fewer than 1,200 daily calories for those assigned female at birth and 1,500 for those assigned male at birth. Any lower than that, and you could easily end up with nutritional deficiencies.
- Choose healthy foods. Load up on good-for-you options like whole grains, lean proteins and fruits and veggies to make sure you meet your nutritional needs and help keep your blood sugar levels steady during your fasting period.
- Talk to your doctor to make sure fasting is OK for you, especially if you have any underlying medical conditions.
- Consider working with a registered dietitian, who can ensure you're meeting your body's needs while you work toward weight loss.
Why you're skipping dinner might prove to be the best indicator of whether you'll gain or lose weight. If it's not done mindfully or as a part of an intermittent fasting regimen, you're less likely to lose weight, and more likely to compensate for the missed meal — and probably with unhealthy choices.
In fact, a December 2020 study in Public Health Nutrition found that when people skipped any meal, their so-called "healthy eating score" was lower compared to when they didn't skip a meal.
- Nutrients: "Associations of Skipping Breakfast, Lunch, and Dinner with Weight Gain and Overweight/Obesity in University Students: A Retrospective Cohort Study"
- The Journal of Nutrition: "Meal Frequency and Timing Are Associated with Changes in Body Mass Index in Adventist Health Study 2"
- Public Health Nutrition: "The effects of skipping a meal on daily energy intake and diet quality"