Study compares the weight loss effect of alternate-day fasting and a daily calorie restricted diet

As some patients find it difficult to maintain a daily calorie-restricted diet, the popularity to fast on alternate-days has increased.

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JAMA Internal Medicine has published a new article reporting the effects of weight loss, weight maintenance, and indicators of cardiovascular disease risk in an alternate-day fasting schedule in comparison with a daily calorie restricted diet.

During the period between October 2011 and January 2015, Krista A. Varady, Ph.D., University of Illinois at Chicago, and coauthors conducted a single-center randomized trial study comprising 100 overweight adults. The participants were assigned randomly to one of three groups  for one year.

In the first group, participants were instructed to fast on alternate days, where fasting was defined as 25% of their calorie needs. On the non-fasting days, or so called “feast” days, participants were allowed 125% of their calorie needs.

Participants in the second group had a daily calorie restriction of 75% of their calorie needs, and the third group had received no diet intervention.  The study was also split into phases: a weight-loss phase (6 months) and a weight maintenance phase (6 months).

The results of the 1-year trial study  revealed  a weight loss of 6.0% in group 1 (alternate day fasting group) and 5.3% in group 2 (daily calorie restricted group). The findings were not significantly different.

The article mentioned several limitations in the research, citing that the 6-month weight-maintenance phase was short and concluded that the consequences of the randomized study proved that the alternate-day fasting schedule did not produce significant weight loss, weight maintenance, or improvement in indicating risk factors for cardiovascular disease compared with the daily calorie restriction diet.