A new study suggests that alternate-day fasting may be more effective for weight loss than other forms of intermittent fasting and traditional calorie restriction.
While further research is encouraged to confirm these findings, a recent review indicates that this “feast and famine” approach to dieting might offer superior weight-loss benefits.
Alternate-day fasting, which involves fasting for 24 hours every other day, has gained popularity in recent years.
Other popular intermittent fasting methods include time-restricted eating (e.g., the 16:8 diet, with a 16-hour fasting period followed by an 8-hour eating window) and whole-day fasting (e.g., the 5:2 diet, with five days of regular eating and two days of fasting).
Researchers from Scotland, the US, Canada, and Germany sought to compare different fasting methods with continuous calorie restriction diets by analyzing existing evidence.
They examined data from 99 studies encompassing over 6,500 participants.
Participants in these studies had an average body mass index (BMI) of 31, with nearly 90% (89%) having pre-existing health conditions.
The research team found that both intermittent fasting diets and calorie-restricted diets resulted in weight loss.
However, compared to continuous calorie restriction, alternate-day fasting was the only strategy that demonstrated a significant benefit in body weight reduction, with participants losing an average of 1.29kg more on this diet, according to the study published in The BMJ.
The authors noted that alternate-day fasting showed a “trivial” benefit compared to both time-restricted eating and whole-day fasting in terms of weight loss.
“Minor differences were noted between some intermittent fasting diets and continuous energy restriction, with some benefit for an alternate day fasting strategy with weight loss in shorter duration trials,” the authors wrote.
“All intermittent fasting strategies and continuous energy restriction diets showed a reduction in body weight when compared with an ad-libitum diet.”
“Of three intermittent fasting diets (ie, alternate day fasting, time restricted eating, and whole day fasting), alternate day fasting showed benefit in body weight reduction compared with continuous energy restriction.”