The theory behind the low-carb diet is that insulin prevents the breakdown of fat by allowing sugar in the form of blood glucose to be used for energy. Proponents of this approach believe that because limiting carbs generally lowers insulin levels, it would cause the body to burn stored fat instead. They believe this method brings about weight loss and reduces the risk factors for several conditions. However, some studies have shown that people who followed certain low-carb diet plans for two years lost an average of nearly 9 pounds, which is similar to the amount of weight lost on higher carbohydrate diets.

This kind of diet benefits includes an emphasis on whole, unprocessed foods and a de-emphasis of refined carbohydrates, such as white flour, white bread, and white sugar. However, there are several downsides. Typically, the first two weeks allow for only 20 grams of carbs per day, which can be dangerously low. Dieters using the low-carb approach consume twice as many saturated fats as people on a diet high in healthy carbohydrates. Low-carb diets are also associated with higher energy intake. The notion that “calories don’t count,” which is prevalent in this kind of diet, is not supported by scientific evidence.