Intermittent fasting isn't a "magic bullet" for weight loss, according to a new study

Jun, 2021 - By WMR

Many people feel that abstaining diets are mostly helpful for weight loss or that it offer definite metabolic health benefits even if they don't help it to lose weight.

The prevalent idea that intermittent fasting diets like alternate day fasting or the '5:2' are the most efficient ways to reduce weight has been debunked by new research published this week. Diets that require people to fast for a few days each week have grown in popularity in recent years, bolstered by photos of people's miraculous weight loss and celebrity endorsements.

However, there is limited information comparing the effectiveness of fasting to more standard diets that try to cut calorie intake over the course of a week. The current study from a team of physiologists at the University of Bath, which was published in the prominent journal Science Translational Medicine, adds to this evidence and suggests that fasting is "nothing remarkable."

Even though their overall calorie consumption was the same, participants in this randomised control experiment lost less weight after fasting compared to those who followed a regular diet.

Participants were divided into three groups in the experiment. Therefore, Group 1 fasted on alternating days, with one day of fasting followed by a day of eating 50% more than usual, Group 2 cut their daily calorie intake by 25% across all meals and Group 3 abstained on alternative days (as did Group 1), but monitored their fast day with a day when they ate 100% more than standard.

At the outset of the trial, participants in all three groups were eating a conventional diet of roughly 2000-2500 kcal per day on average. The two energy restricted groups lowered this to between 1500 and 2000 kcal on average over the three-week monitoring period.

A randomised controlled experiment was conducted in lean adults to determine the effects of fasting and energy restriction on weight loss and metabolic health.