Time restricted eating & weight loss

Executive summary

* This week's note reviews a randomised controlled trial, which assessed whether calorie restriction with time-restricted eating was better than calorie restriction alone.

* The study involved 139 patients with a BMI between 28-45. They were assigned to either calorie restriction alone (approximately 75% of baseline calorie intake) or the same calorie restriction but with the additional restriction of only being able to eat between 8am and 4pm.

* The primary outcome of interest was weight loss. Secondary outcomes were waist circumference, BMI, amount of body fat and measures of metabolic risk factors.

* There were no significant differences between the two groups for any measure of interest. Time-restricted eating made no additional difference beyond the calorie restriction.

* The results disproved the 3,500 calorie theory, which states that one pound of fat will be lost for every 3,500 calorie deficit created.

* The rest of the note reviewed the wider literature on time-restricted eating to see if the right study has been done and what we know generally about this topic of increasing interest.