Scientific research supports intermittent fasting as an effective weight-loss tool. One review of literature, published in Obesity Reviews in 2011, found that up to 12 weeks of intermittent calorie restriction – similar to the Eat Stop Eat plan – was as effective in weight loss as reducing calories by a set amount every day; in addition, it helped dieters retain more lean muscle mass. This type of intermittent fasting may produce other health benefits, too. A review published in The American Journal of Clinical Nutrition in 2007 discovered that fasting on alternate days led to lower risk of chronic disease in animals, although more studies on humans are needed. Pilon cites reduced inflammation and cellular “cleansing” as other possible benefits. Finally, Eat Stop Eat may be less confusing and more straightforward than diets in which you have to limit an entire food group, like fat or carbs.

Having to fast every week may not fit your lifestyle. Richard Bloomer, chair of health sport sciences at the University of Memphis in Tennessee, told the journal CMAJ in 2013, “Most people aren’t going to be able to do it.” Pilon admitted to the same reporter that Eat Stop Eat is best done privately because it interferes with regular social interactions, like meals with family or friends. The diet may cause headaches and crankiness in some people, and is not a viable choice for diabetics, pregnant women or those with a history of eating disorders like bingeing. The plan permits artificially sweetened drinks, which may actually make you crave sweets or choose unhealthy foods because you have “saved” calories. Finally, Eat Stop Eat doesn’t make any specific meal-plan recommendations for non-fasting days, leaving you to demonstrate enormous self-control and judge for yourself what to eat – an area in which many people who struggle with their weight need guidance.