Does sleep affect weight loss?

By K Diet, Exercise, FAQs, FAQs body fat, lose weight, obesity, sleep Comments Off

Sleep and Weight Loss

When it comes to weight loss, the emphasis is typically placed on diet and exercise at the expense of other guidelines. While many dieters follow nutrition and physical activity recommendations, sufficient sleep is often missing. Though the Centers for Disease Control and Prevention (CDC) recommends at least seven hours of sleep for most adults¹, a Gallup poll found 40% of Americans fail to meet this recommendation².

As we increase our understanding of obesity, we are learning it’s a much more complex issue than a simple calorie equation. Research is now showing lack of sleep increases the risk of unwanted weight gain and obesity.

What does research say about sleep and weight loss/obesity?

Study 1: Effects of Experimental Sleep Restriction on Weight Gain, Caloric Intake, and Meal Timing in Healthy Adults

This study examined the effects of sleep restriction on weight gain, daily calorie intake, and meal timing in 225 healthy adults. The participants were divided into two groups. The sleep restricted group was allowed four hours in bed each night while the second group was allowed 10 hours³.

Researchers found the sleep restricted group consumed 130 more calories, ate more meals, and gained 2.1 more pounds than the other group. Researchers concluded that sleep restriction promotes weight gain³.

Study 2: Impact of insufficient sleep on total daily energy expenditure, food intake, and weight gain

This study examined the effects of insufficient sleep on energy expenditure, food intake, and weight gain. Researchers looked at the effects of insufficient sleep over the course of five days. They found insufficient sleep increased energy expenditure by 5%, however, calorie intake increased beyond what was needed to maintain body weight. This led to an increase in body weight of 1.8 pounds⁴.

Study 3: Insufficient Sleep Undermines Dietary Efforts to Reduce Adiposity

This study examined whether insufficient sleep affected a calorie restricted diet. The study included 10 overweight adults and split them into a group that had either 8.5 or 5.5 hours of sleep per night. Researchers found insufficient sleep drastically decreased the proportion of weight lost as fat. The 8.5 hour sleep group lost 3.1 pounds of body fat while the 5.5 hour group lost only 1.3 pounds of body fat⁵.

Researchers also found the amount of fat free mass lost was greater in the 5.5 hour group (5.3 pounds) than the 8.5 hour group (3.3 pounds). Researchers concluded sufficient sleep leads to better maintenance of fat-free body mass during periods of energy restriction⁵.

What does this research mean?

Current research indicates sleep quality has a significant effect on weight loss. The common theme across all three studies was insufficient sleep led to an increased calorie intake and weight gain. In the third study, less sleep negatively affected the results of a diet.

On the other hand, sufficient sleep preserved lean body mass (muscle) during weight loss. Sleep is a risk factor in obesity. Quality sleep enhances the results of diet and exercise and should therefore be included in a comprehensive weight loss strategy.

Good Sleep Habits

Increasing sleep quality is an often overlooked way to improve weight loss results. The CDC recommends a few habits to improve sleep hygiene including¹:

go to sleep and wake up at the same time every day, including weekends
ensure your bedroom is quiet, dark, and temperature is set comfortably
remove electronic devices from your bedroom
avoid large meals, caffeine, and alcohol before bed
physical activity during the day helps you fall asleep more easily

The Bottom Line

Focusing solely on diet and exercise misses an important piece of weight loss. Getting the recommended amount of sleep increases body fat losses, preserves lean body mass, and decreases calorie intake.