Have you heard of intermittent fasting? Basically, it's a diet that involves a period of regular eating followed by one of fasting. The fast can last as long as 24 hours and involve only drinking water, black coffee or tea, or it can last for just eight hours. In other iterations, the fast period involves a restriction of calories – such as consuming only 600 calories on the fast day – which is much more feasible for many people. After all, who can get any work done on a hungry, empty stomach?
Fasting has been around for ages and is often part of religious practice. In general, fasting is healthy if not taken to extremes and dieters get sufficient nutrients and enough calories to function. So, moderate fasting is fine for most people, but is it effective for weight loss?
A recent study from the University of Illinois at Chicago found that intermittent fasting in combination with calorie restriction and liquid meals helped obese women both lose weight and lower their risk of coronary heart disease. A 2007 clinical review found that intermittent fasting could likely protect against Type 2 diabetes, cancer and heart disease. A controlled trial in 2007 found that fasting for normal weight subjects was not effective without calorie restriction. However, more research is required to determine which patterns of fasting and calorie restriction are most effective, and in turn, if intermittent fasting is more effective than other weight loss strategies.
Other research has shown that fasting could be positive for brain aging and function. Still, until there's better research, for adults of regular weight who are trying to get in shape, it's probably better to stick to healthy eating and exercise for weight loss.