Restricting Eating to Certain Hours Bolsters Weight Loss

A randomized trial showed that eating within eight hours, in addition to diet and exercise, helped obese people lose weight.

Those who reduced all calorie intake to 8 hours (7am to 3pm) lost an additional 2.3 kg (5.1 pounds) in a 14-week study compared to those who ate for 12 hours or more. , reports Courtney Peterson, Ph.D. University of Alabama at Birmingham, and her colleagues.

They note that this weight loss is equivalent to eating 214 fewer calories per day. JAMA Internal Medicine.

An average of 6.3 kg (13.9 lb) was lost when the restricted meal time group received weight loss treatment (energy restriction).;P<0.001), 4.0 kg (8.8 lb; P.<0.001).

The 8-hour diet specifically did not help much in losing body fat. Similarly, there was no significant difference in the ratio of fat loss to weight loss (-4.2%).

However, a secondary analysis of 59 participants who completed the 14-week trial demonstrated that the 8-hour eating window was more effective in excreting body fat (-1.8 kg). [-4.0 lb]95% CI -3.6 to 0.0 kg, P.=0.047) and trunk fat (-1.2 kg) [-2.6 lb]95% confidence interval -2.2 to -0.1 kg, P.=0.03).

Adding a meal time restriction window to the diet also reduced diastolic blood pressure (-4 mm Hg, 95% CI -8 to 0 mm Hg, P.= 0.04), although this was the only cardiometabolic risk factor that appeared to improve with time limit. and improved sleep parameters.

“Our data suggest that early timed eating is possible, as participants adhered to an average of 6.0 days per week and most participants adhered to at least 5 days per week. .

In an accompanying commentary, Schalender Basin (MB, BS) of Brigham and Women’s Hospital in Boston quickly compared the trial to another recent time-limited trial published earlier this year. New England Journal of Medicine.

Following a similar methodology, the study found that following a time-restricted diet in addition to caloric restriction did not lead to a significantly greater amount of weight loss compared to a calorie-restricted diet alone (-1.8 kg). . [-4.0 lb] difference; P.=0.11).

One of the main differences between the two trials is that the current study had an earlier 8-hour window (7am-3pm and 8am-4pm). Another difference, Bhasin notes, is that previous trials did not set a specific window for the control group, whereas Peterson’s group instructed the other groups to eat over a 12-hour window each day. I pointed out that Also, the current trial lasted only 14 weeks for him, compared to a year in the previous trial.

Regardless of these differences, Bhasin said both trials confirmed “a high level of adherence to the dietary regimen.”

“The scientific assumptions and preclinical data regarding the effects of time-restricted diets are encouraging, but inter-study inconsistencies make it difficult to draw strong inferences from these well-conducted, relatively small trials.” said Bhasin.

For this study, Peterson and team randomly assigned 90 adults with a BMI of 30 to 60 (mean age 43 years, 80% female) into each of two groups. All participants received weight loss counseling, including energy restriction, at the UAB Weight Loss Medicine Clinic, followed a calorie-restricted diet of 500 calories per day below resting energy expenditure, and followed weekly I exercised for 75-150 minutes. activity.