Dietitian Catherine Saxelby shares the latest findings on time-restricted-eating.
A lot of people ask me about losing weight using intermittent fasting such as the 5:2 Diet (where you ‘fast’ or eat sparingly for 2 days out of the 7) or time-restricted-eating such as the 16:8 Diet (where you limit your eating to only 8 hours). I can see why this form of dieting is attractive – there are few rules around the foods you eat and no calorie or carb/fat counting. Plus, you don’t have to be ‘on a diet’ for long periods.
New research shows that time-restricted-eating (using an eating window of 8 hours from 12 noon to 8pm) doesn’t produce any more weight loss than eating the standard three meals a day. Although there are some criticisms of this study such as the fact that the subjects didn’t restrict the overall amount they took in.
A 12-week study of 116 overweight or obese people found no statistically significant difference in weight loss between people who restricted their eating and those who didn’t.
Specifically, there were no differences in fat mass, fasting insulin, glucose, HbA1C (a measure of long-term blood glucose) or blood lipids between the two groups.
Scientific evidence in humans is still thin. If time-restricted eating works for you, it may well be that you eat less during your window of eating time – and that produces the weight loss or weight maintenance.
However, don’t write off intermittent fasting entirely — there may be benefits from fasting, such as reduction of inflammation, that are unrelated to body weight.