Most people know that eating less and choosing healthy foods are important for weight loss, but recent research shows that the timing of your meals and snacks matters, too. Earlier is better—think a hearty breakfast and lunch and a light dinner.
“We are metabolically more efficient in the morning,” says UNC Health registered dietitian Elizabeth Watt. “Your body is better equipped to burn calories earlier in the day.”
The problem is, about half of Americans consume most of their calories in the evening, says UNC Health endocrinologist and metabolism specialist Andrea Coviello, MD.
Watt and Dr. Coviello explain why meal timing matters and how to shift your eating habits to give you a metabolic boost.
The Case for Eating Early
Eating earlier in the day works better with your body’s circadian rhythm, its internal clock.
Your body releases two hormones that make you hungry in the morning: ghrelin, known as the “hunger hormone,” and cortisol. These hormones prompt you to eat while your body is ready to burn the calories.
“That’s why some people say that eating breakfast makes them feel hungrier during the day,” Watt says. “It’s supposed to.”
It’s how our bodies were created to function.
“If you think about cavemen, they would get up, eat, gather food and work, and go to bed when it got dark,” Watt says. “Their lifestyle was tied to the sun going up and down.”
Now, long workdays, harrowing commutes, kids’ activities and the lure of streaming shows have many people staying up later and eating later. In the evening, however, the body clock winds down, and most of what people eat then is stored as fat.
“When you eat late at night, your body can’t break it down,” Watt says. “Your body doesn’t want to digest and prepare for sleep at the same time.”
Research shows that eating late can raise ghrelin levels and suppress levels of leptin, the hormone that causes you to feel full. Eating late also throws blood sugar levels for a loop, which can contribute to weight gain over time.
“When you eat, your blood sugar goes up,” Watt says. “At night, the body is not able to bring those levels down as well as it can in the morning or during the day.”
Having high blood sugar levels at night can also interfere with a good night’s sleep.
“Adequate sleep is important for weight loss,” Dr. Coviello says. “People with disordered sleep tend to gain more weight in general.”
Quality and Quantity of Food Are Still Most Important
While eating earlier in the day is beneficial for weight loss, experts say the most effective way to lose weight is to reduce your caloric intake.
“Research is starting to show positive metabolic shifts that relate to the timing of eating, as well as improved cholesterol and insulin levels,” Dr. Coviello says. “But changing meal timing has not shown to be more effective for weight loss than limiting the total amount of calories you consume.”
For effective weight loss, on average, women should reduce their calorie intake by 500 per day, and men should cut back by 750 per day, Dr. Coviello says.
And it’s still best to focus on eating healthy foods in appropriate proportions. Go for whole grains, lean meats, and fresh fruits and vegetables. Stay away from processed foods that have a lot of added sugar and salt to extend their shelf life.
“Avoid highly processed foods. Simply, avoid foods that come in a can, a box or a bag—except frozen fruits and veggies,” Dr. Coviello says.
Tips for Shifting Your Eating Habits
If you want to shift your meals to be earlier in the day, here are some tips to get started:
- Don’t skip breakfast. Eat a hearty breakfast with protein in the morning, such as overnight oats, eggs or a smoothie.
- Prep your meals. Spend time over the weekend cooking meals or prepping items you might need to cook throughout the week. Having meals prepared will save time, help you eat earlier and keep you from swinging by a drive-thru.
- Have a bigger breakfast and lunch and a lighter dinner. Don’t get caught up in having to eat a meat, carbohydrate and vegetable for dinner, Watt says. You can mix it up and eat your carbohydrates earlier in the day, then have a lean meat and vegetable for dinner. It’s best to have already eaten most of your calories for the day by dinnertime, she says.
- Eat snacks. If you don’t like to eat large meals, break things up by eating smaller meals and snacks throughout the day. You’ll want to incorporate protein, carbohydrates and fiber. Fruit, crunchy vegetables, low-sugar Greek yogurt and nuts are all great options, Dr. Coviello says.
- Don’t eat past 8 p.m. Most of what you consume after 8 p.m. will be stored as fat. Instead, reach for a low-calorie, decaffeinated tea or coffee, which can help to curb your appetite.
Finally, know that it’s OK to not eat perfectly every day.
“You don’t have to be an A student,” Dr. Coviello says. “Set goals that are achievable. If you follow healthy eating principles most days in a week, your long-term health will benefit.”
Talk to your doctor if you’re interested in having a dietitian help you develop healthy eating habits. Need a doctor? Find one near you.