Fasting Diets May Lead to Muscle Loss

Protecting your overall health with a nutritious diet, regular exercise, stress management, and proper sleep are important to help keep the body strong and immune system robust.  A recent study of intermittent fasting may have you reconsidering this recent weight-loss eating trend. 

According to a New York Times report, a recent study, published in the JAMA Internal Medicine, tracked overweight participants who followed a 16:8 diet that called for 16 hours of fasting and 8 hours of eating between noon and 8 p.m.   The restricted eating plan resulted in minimal weight loss – between 2 and 3.5 pounds, which was only slightly more than the control group who ate three structured meals each day.  Researchers were surprised to find that the fasting group lost most of their weight in lean mass, including muscle, rather than body fat. 

The findings of the study are concerning, especially for older adults who naturally lose muscles as they age.  Muscle mass is important for seniors to protect against falls and disability in older age and is associated with a lower mortality rate.  Researchers suggest that muscle loss may have occurred because of a decrease in protein consumption by the fasting group.  Prior research has also found that people are better able to metabolize food earlier in the day, rather than in the afternoon and evening. 

Critics of the research say it is too short a study to be definitive but it does question the benefits of time-restricted eating.  Other studies have found that people can maintain their muscle mass while fasting by eating more protein and doing resistance training.  The evidence of the University of California, San Francisco study was, however, enough to cause lead author Dr. Ethan Weiss who had been practicing intermittent fasting since 2014 to stop the habit and begin eating breakfast again. 

Fasting participants in the study lost just half a pound more than the control group, but 65 percent of the weight lost by the fasting group was from lean mass, which is double what is considered normal when losing weight.  Learn more about what foods will help build lean muscle by following this link to Healthline Nutrition. Don’t forget the importance of staying active and participating in a combination of aerobic and strength-training exercises. 

As with any change in diet or exercise program, it’s important to talk first with your doctor and start out slowly, remembering it will take time; between 6 to 8 weeks, to see improvements.