How Meal and Sleep Schedules May Help You Lose Weight


Photo by: nicolamargaret


For years, the medical community has disregarded the notion of late night eating impacting body weight when total daily calories stay the same. However, the latest research reveals how meal timing can affect your weight and blood sugar levels, which may impact your diabetes risk. It’s your body’s natural clock calling the shots.

For more insight, I caught up with Frank A.J.L. Scheer, Ph.D., Associate Professor of Medicine at Harvard Medical School and the director of Medical Chronobiology (how the sun and moon affect our bodies’ rhythms) at Brigham & Women’s Hospital.

Scheers’ key finding is, “It is not just important what we eat, but also when we eat, and this can be traced back mostly to the tight reciprocal connection between the circadian clock and metabolism.” Here are the details you need to know.

Eating a bigger breakfast may help you lose more weight

Breakfast is still the most important meal of the day. One study found that early eaters lost four more pounds than people who ate big dinners, despite both groups having the same calorie levels, physical activity, appetite hormones, and hours of sleep. In another study, big-breakfast eaters lost about 13 more pounds. This could be due to how the body burns the most calories while digesting breakfast and fewer during dinner, as was found in a study on shift workers.

As for lunch, the earlier the better, as supported by a study following bariatric patients for six years finding that those who ate lunch before 3 p.m. lost significantly more weight than late-lunch eaters.

Many people handle carbs best in the morning

“The most convincing effects of circadian misalignment are on glucose control and have been shown by independent studies and laboratories,” Scheer highlights. Circadian misalignment occurs when your sleep and wake routine changes drastically against your body’s 24-hour clock, as in jet lag and shift workers’ schedules.

Even for someone who clocks a regular schedule, the body appears to handle morning carbs the best and evening carbs the worst, since glucose tolerance (how your body handles the carbs you eat) is impaired in the evening, resulting in blood sugars staying at healthy levels, rather than sky high. Long-term, healthy blood sugar levels reduce diabetes risk.

What is the best time to eat dinner?

One study suggests that eating four hours before bedtime is better for your blood sugars than an hour before bedtime.

Scheer notes, however, “Like most short-term behavioral interventions, this is not going to immediately cure one’s diabetes.” He adds, “The effects of eating at night for glucose control are unexpectedly large, especially considering that these effects are observed on such a short time scale.” But since blood sugars change more rapidly than body weight, it’s easier to test the former in a lab. Scheer is quick to point out that people who already have diabetes, surprisingly, have the best glucose tolerance in the morning, due to a variety of possible causes.

The sleep diet

Another study found that people who slept only four hours had half the leptin levels as people who slept nine hours. Leptin, a hormone that regulates appetite, prevents us from wanting to eat constantly, therefore, when you get enough sleep you’re better equipped to control your appetite.

How melatonin affects sleep and blood sugars

Melatonin, a hormone that rises in the body at night and helps you fall sleep, inhibits insulin release, according to studies, putting your blood sugars out of whack. This effect on blood sugars is believed to affect about 50% of people due to a type of DNA they carry, according to Scheer. Then, what is one to do when crossing time zones?

Scheer advises, “The most obvious way that melatonin can help the average healthy person is against jet lag when traveling eastward.” Scheer explains that supplementing with 0.3 milligrams of melatonin right before bedtime can help your body move your body’s circadian system from wake to sleep. However, Scheer points out that while this may shift your body clock by a half hour, properly timed light has stronger effects on sleep. Therefore, dim those lights and turn off your cell phone, the TV, and other glaring electronics earlier in the evening.

Your sleep schedule can also affect blood pressure and inflammation

Scheer’s findings also concluded that people whose wake and sleep schedules were not aligned with their body clocks (i.e. shift workers) had higher blood pressure and inflammatory markers.

How to tweak your sleep and meal schedule to lose weight and reduce diabetes risk

1: Make breakfast your biggest meal of the day. Make lunch mid-size and dinner the smallest.

2: Eat dinner four hours before bedtime, rather than right before bedtime.

3: Eat lunch earlier, and always before 3 p.m.

4: Switch off the lights earlier when crossing time zones Eastward. Melatonin supplementation may also help.

5: Get the recommended 7 to 9 hours of sleep per night.

Note: If you take a medication for diabetes, always talk with your doctor or registered dietitian before making changes to your carbohydrate intake.

Michelle Dudash is a registered dietitian nutritionist, Cordon Bleu-certified chef consultant, and the author of Clean Eating for Busy Families.

Related Links:

8 Foods to Avoid Before Bedtime

Next Up

Can Tapping Help You Lose Weight?

Some claim this psychological practice can help you drop pounds quickly. A dietitian weighs in.

Can Avocado Toast Help You Lose Weight?

Maybe the Millennials are on to somthing...

Do Diet Drinks Actually Help With Weight Loss?

A new study shows that no- or low-calorie sweetened drinks can be just as, if not more, effective as swapping in water in place of sweetened drinks.

The Best Vegetables to Eat When You're Trying to Lose Weight

Here are seven especially super veggies when you're slimming down.

Unexpectedly Helpful Foods for Weight Loss

Focusing on these foods may help you peel off the pounds more quickly.

Do Sleep Foods and Drinks Really Work?

From tart cherry juice to sleep cereals, a nutritionist weighs in on whether these foods are worth having before bed.

The Spanish Meal

Dining in and out in Spain

5 Signs You've Gotten a Good Night's Sleep

How to tell when you've actually slept well.

What Experts Want You to Know About Sleep

We asked sleep gurus to share their top tips for optimizing those zzz's. Their suggestions may surprise you.

Here Are the Best Fats for Weight Loss

Good-for-you fats exist, and you need to start eating them.

More from: