If you have any interest in dieting, health, and wellness, you’ve probably heard of the various intermittent fasting diets that have been all the rage over the past few years. There are many different fasting diets, but they all share the same idea: the person avoids eating for a portion of his or her day or week. But do fasting diets work, or will they eventually be designated to the rubble pile of history?
Here’s what the science says.
One study, conducted by the National Institute on Aging in 2003, found that after 20 weeks, mice who were allowed to eat as much as they wanted on one day but not fed the next day, lived longer and had lower levels of glucose and insulin and improved insulin sensitivity compared to mice that were allowed to eat freely all of the time. But more importantly, these levels matched or were even better than those of mice who ate 40 percent fewer calories than normal every day. The scientists involved in the study concluded that alternate day fasting was just as likely to improve health and life expectancy as a daily calorie restriction.
Another study, published in the American Journal of Clinical Nutrition in 2005, took 16 normal weight adults that followed an alternate day fasting regime for three weeks. On fasting days they had nothing but calorie-free drinks whilst on feasting days they were allowed to eat whatever they wanted. At the end of the study, the adults had lost an average of 2.5 percent of their initial body weight and 4% of their fat mass. However, most participants felt extremely hungry throughout the study and said they couldn’t sustain this type of eating pattern for long.
But the benefits of intermittent fasting may go beyond weight loss and diabetes control. One study conducted in 2014 suggests that intermittent fasting can help humans fight diseases, stating, “Emerging findings from studies of animal models and human subjects suggest that intermittent energy restriction periods of as little as 16 hours can improve health indicators and counteract disease processes. The mechanisms involve a metabolic shift to fat metabolism and ketone production, and stimulation of adaptive cellular stress responses that prevent and repair molecular damage.”
So, while more studies are being done and scientists are (wisely) hesitant to make any definitive claims, research does support that there may be something to intermittent fasting. Those who are curious to try it should gradually ease into it, as with any other diet, and should discontinue the diet and consult their doctor if they notice any negative side effects.
