The key to weight loss

A study shows that it may be sleep duration and quality

| THE INDEPENDENT | A new study has shown that short-term low calorie diets can increase sleep quality in adults with obesity.

The study also demonstrates that lack of sleep may prevent weight loss maintenance in adults with obesity and that regular exercise may promote the maintenance of good sleep.

Adults ages 18 to 60 should aim for at least 7 hours of sleep each night to promote health and well-being, the American Academy of Sleep Medicine recommends. However, data from the (CDC) shows that more than 30% of American adults regularly fail to get enough sleep.

Studies have shown poor quality, and limited sleep may increase the risk of metabolic disorders, weight gain, and obesity. Lack of quality sleep has also been shown to increase the desire for high calorie and high carbohydrate-containing foods associated with weight gain.

New research has found that lack of quality sleep can also undermine people’s attempts to maintain weight loss after dieting.

Researchers with the University of Copenhagen presented their findings at the 2022 European Congress on Obesity held in Maastricht, Netherlands.

Dr. Signe Torekov, the study lead and a professor of clinical translation metabolism, spoke with Medical News Today.

“Adults who aren’t sleeping enough or getting poor quality sleep after weight loss appear less successful at maintaining weight loss than those with sufficient sleep.” Dr. Torekov explained.

The study

Using data from the S-LiTE randomised placebo-controlled trial, the researchers studied the quality and duration of sleep in 195 adults with obesity. The participants followed a low calorie-restricted diet for 8 weeks and lost an average of 12 percent body weight.

For the following 12 months, participants committed to receiving either a: daily placebo Injection, daily placebo injection and exercise, daily 3 mg injection of the weight loss drug liraglutide, daily liraglutide injection and exercise.

Sleep quality was measured by a questionnaire using the Pittsburgh Sleep Quality Index (PSQI), where a score of 5 or more indicates poor sleep and below 5 good sleep. The participants wore accelerometers to measure sleep duration before and after the 8-week low calorie diet and at weeks 26 and 52 of the weight maintenance study.

Low calorie diet increases sleep duration

Researchers found that sleep quality increased by 0.8 global PSQI score points and sleep duration increased by 17 minutes per night after the initial 8-week restricted-calorie diet.

MNT spoke with Dr. Jane Odgen, a professor of health psychology who was not involved in the study, she highlighted that “Weight and sleep are linked – we don’t know which way round i.e. poor sleep causes weight gain or weight causes poor sleep.”

Giving her take on the study, Odgen explained: “The first part of the study shows weight loss is associated with improved sleep.” However, she added a note of caution: “But for this part, there was no control group and no randomisation. So it might not have been the weight loss and could have been something else, such as time, being in a study, or eating more fruits and vegetables regardless of weight loss.”

The longer-term study showed that adults with obesity who slept less than 6 hours a night or had poor sleep quality increased their BMI by 1.1 kg/m2. In comparison, obese adults who achieved over 6 hours of quality sleep each night reduced their BMI by 0.16 kg/m2.

“The second part shows less sleep and poor quality sleep at baseline predicted weight gain,” says Dr. Odgen. “This was not the randomised bit. So an association but not causal, such as poor sleep, might lead to eating more in the night, which leads to weight gain, and it’s not the sleep,” she added.

Can exercise aid sleep quality?

Researchers found that the more active participants maintained the diet-related sleep quality improvement compared to the less active participants.

“Weight loss maintained with exercise seems promising in improving sleep,” said Dr. Torekov. “Adults who aren’t sleeping enough or getting poor quality sleep may benefit from sleep pattern support as well as weight loss maintenance support.”

She added that “before initiating weight loss maintenance, it may be helpful to identify sleep patterns.”

When asked about the research findings, Dr. Ogden said that “[..] the take-home message is that sleep and weight are associated but we still don’t know whether this is causal. But it does indicate that exercise promotes the maintenance of good sleep.”

“The best intervention would therefore be to do more exercise, improve your sleep, and then maybe also show weight loss,” Dr. Odgen explained.

Sleep statistics worldwide

• 62% of adults around the world say they don’t sleep as well as they’d like (Philips Global Sleep Survey, 2019).
• As many as 67% of adults report sleep disturbances at least once every night (Philips Global Sleep Survey, 2019).
• 8 in 10 adults around the world want to improve their sleep but 60% have not sought help from a medical professional (Philips Global Sleep Survey, 2019).
• 44% of adults around the world say that the quality of their sleep has gotten worse over the past five years (Philips Global Sleep Survey, 2019).

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