health guides

What makes us fat?

A few studies have pointed to poor sleep, increased screen time, depression, and stress as possible contributors to overeating and weight gain. Chronic stress, in particular, seems to increase calorie-dense food consumption and can lead to abdominal fat gain.

The LIFE study aimed to determine how sleep, amount of time spent in front of computer and TV screens, depression, and stress affect weight loss success. Sponsored by the National Center for Complementary and Alternative Medicine, the study was a two-part trial investigating alternative strategies for weight loss management. Phase I of the study was the weight loss portion; Phase II dealt with ways to keep the weight off and is discussed elsewhere.

During the six-month trial, 472 overweight and obese adults (average age 55) underwent an intensive behavioural weight-loss intervention that included the following:

• Eating 500 fewer calories per day.
• Eating a low-fat diet rich in fruits and vegetables (consistent with the Dietary Approaches to Stop Hypertension, or “DASH,” diet).
• Getting some moderate intensity physical exercise every day, gradually increasing up to one hour per day and at least 180 minutes per week.
• Recording everything they ate and drank.
• Setting weight loss and exercise goals and creating action plans to meet those goals.
• Attending 22, 90-minute weekly group sessions led by nutrition and behavioural counsellors.

De-stress to shed pounds

At the end of Phase I, the participants lost an average of almost 14 pounds (6.3 kg), and 60% of them lost at least 10 pounds (4.5 kg) and went on to Phase II.

Longer sleep times and lower stress at the beginning of the study predicted greater weight loss during Phase I. Those participants who slept less than six hours per night and had the highest levels of stress were only half as likely to lose enough weight to go on to Phase II as were those who slept between six and eight hours per night and had a low stress score.

Weight loss, in turn, was associated with declines in stress and depression among the participants. Screen time didn’t appear to predict weight loss success in the study, but the amount of exercise did.

“These results suggest that early evaluation of sleep and stress levels in long-term weight management studies could potentially identify which participants might benefit from additional counselling and resources,” said the study’s lead author, Dr. Charles Elder of Kaiser Permanente Center for Health Research in Portland, Oregon.

(Int J Obes 2011;doi:10.1038/ijo.2022.60)