The efficacy of intermitting fasting for weight loss by Chris Graham
[Chris Graham is a graduate student at The University of Texas at Tyler and is currently studying Kinesiology. He is currently a sport performance intern at Athletic Lab.] Intermittent fasting (IF) has been popularized in the recent years as a method of weight loss and there are many people who claim to have found success using this method. What exactly is IF, and is it an effective and sustainable method to achieve weight loss? First off, IF is the practice of not consuming food for an extended period of time (typically 12+ hours) which is called your fasting time. This is followed by a fast time where you can eat ad libitum. There are a variety of ways to accomplish this, but one of the most common is to alternate fast and feast days for an extended period (3-8 weeks). In a recent review comparing IF and caloric restriction in overweight and obese individuals, Varaday (2011) found that both diets had similar results on weight loss 4-8% from IF and 5-8% from caloric restriction. However, in the IF studies 10% of the weight loss was from fat free mass compared to 25% in the caloric restriction studies (Varaday, p. e599). This retention of more fat free mass compared to regular caloric restriction proved to be more beneficial in improving body composition, and may be a result of average HGH increases of 1,300% in women, and nearly 2,000% in men during a 24-hour fast (Intermountain Medical Center, 2011). This spike of HGH protects your current muscle mass while also stimulating the breakdown of fat cells. In a separate study examining the effects of IF in resistance trained individuals, one group was assigned a time restricted feeding [...]
