Our Longevity Diet

A recent study supports the idea that intermittent fasting can be a useful technique for weight loss, even among obese subjects. Long-term results, of course, would require a commitment to lifestyle that incorporates a fasting regime, but this short-term study is suggestive of the potential.

The Study

Doctoral students Surabhi Bhutani and Monica Klempel, and clinical coordinator in physical therapy Emily Church, conducted a 10 week study on 16 clinically obese people. The subjects all weighed in excess of 210 pounds and had body mass indexes (BMI) between 30 and 39.9. There were 12 women and 4 men in the study, aged 35 to 65. None was diabetic, and none were taking weight-loss medication, nor lipid or glucose lowering medicines.

The weights of the study subjects had been stable for the three months preceding the study. For the first two weeks of the trial they ate normally and maintained their normal activity levels, during which time their weight, blood pressure, heart rate and blood chemistry were measured.

For four weeks the subjects were allowed to eat normally one day, then on the fasting days they were fed a single meal at lunch time with about 20 to 25 percent of their normal daily energy needs. For the last four weeks of the study subjects were allowed to set their own meal size and composition, as well as schedule.

Subjects lost from 10 to 30 pounds each, and their blood pressure and heart rate were lowered. Total cholesterol and circulating fat levels were also reduced.

Source

University of Illinois at Chicago; reported at http://www.medicalnewstoday.com/articles/169885.php on 5 Nov 2009

Comments

It is surprising that the results were so good for such a poorly designed study. There appears to have been no control group, and it is not exactly clear how much weight loss came during the semi-supervised ‘fast’ days, and how much from the self-monitored weeks that followed. The researchers took the ‘alternate day’ part of alternate day fasting too literally, and designed a diet that effectively had two short fasts interrupted by a meal on ‘fasting’ days, alternating with normal eating days. If they had used 24 hour fasting periods alternating with 24 hour eating periods, it would have been much more comfortable (and sustainable) for the subjects. This study does suggest that intermittent fasting is an effective weight-loss technique, however, and deserves closer attention from researchers and nutritionists.