Obesity is a leading health problem in the United States and obesity-related deaths due to diseases such as diabetes type 2 and heart disease are on the rise.  Despite the abundance of weight-loss programs and treatments available, the health, fitness, and medical communities are unable to make a dent in the skyrocketing epidemic.  Many of those afflicted are looking for help, and there is an abundance of research that points to a particular diet and treatment, yet none of them lead to long-lasting weight loss because the urge to eat is just as strong as the instinct to survive.  

One such treatment is fasting.  Fasting or intermittent fasting has long been a part of multiple religious cultures.  It can be as simple as skipping a single meal, skipping whole days, or eating for only certain hours of the day.  Currently, there is an increasing interest in weight-loss methods that use time-restricted feeding such as intermittent fasting.  This method is where the hours or days a dieter is allowed limited food access are alternated with hours or days of normal food intake.  The limitation can be either lower amounts of food or a complete ban on food. 

Recently, a study looked at alternating days of normal versus limited food intake[1].  To determine the benefits of intermittent fasting to treat obesity, researchers used rats that were lean and obese.  The lean rats being more physically active than the obesity-prone rats.  The researchers felt that intermittent fasting would induce loss of fat and lean mass in both rat types with the obesity-prone rats losing more bodyweight.  In the study, rats were allowed free access to food on fed days, alternating with fasting days in which the rats were not allowed to eat.  The rats were weighed daily, and their body composition was analyzed weekly.  All rats lost weight over eight weeks of intermittent fasting.  The obesity-prone rats lost significantly more fat mass and body weight compared to the lean rats.  Compared to standard calorie restriction, intermittent fasting decreased the loss of lean mass while enhancing the loss of fat mass.  This finding is contrary to what most nutrition experts would expect.   

The bottom line:  Intermittent fasting was thus found to be successful in inducing weight loss in obese rats.  Fasting appears to be an effective means to cause fat loss and could be an effective means to produce weight loss.  More research is needed not only because the number tested was low, but the test subjects were rats. I know rats are not humans, but humans are similar and this is one more study to show that fasting can be an effective means to lose weight.  Although similar results are expected in humans, human research is needed to confirm this.