With recent trends in obesity and expanding body size, nutrition and weight loss have become popular topics in everyday conversations. The ever-expanding diet industry has spawned numerous wacky nutrition products and tips to cash in on our growing obsession. Many of these “fad diets” make pseudoscientific claims that appeal to people eager to lose a few pounds. The focus around a particular food group or secret health food gives many of these diets the mystique to become popular. In recent history, one of the most popular fad diets has centered around consuming only grapefruit.

The grapefruit diet, also known as the Hollywood diet, originated in the United States in the 1930s. The diet centers around the claim that grapefruit has extraordinary weight-loss properties, such as a fat-burning enzyme . The grapefruit diet is considered unhealthy by most nutritionists due to the lack of essential vitamins and minerals and the low number of calories (less than 1,200 calories per day). On the other hand, incorporating a grapefruit into every meal can be beneficial to a healthy person’s diet, as long as the dieter is not allergic to grapefruit or taking medications that interact with citrus.

The grapefruit diet is a low-carb diet that usually occurs in a two-week cycle (12 days on the diet with 2 days off) repeated until the desired body weight is achieved. Proponents of the diet suggest that grapefruit helps burn body fat when eaten with foods high in dietary fat. Consequently, the diet includes the consumption of meat, eggs, and fish, while restricting the consumption of sugars, sweet fruits, grains, and other carbohydrate sources. For best results, the diet calls for three high-fat, high-protein meals, supplemented with a grapefruit, and with a daily caloric intake of less than 1,200 calories.

The diet gained popularity in the 1970s after being mislabeled “the Mayo Clinic diet.” Although the Clinic had no connection to the diet, the brand helped make the diet popular. In the 1980s, the diet was reduced to just 10 days on 2 days off, earning it the nickname “10-day, 10-pound diet.” A 2004 study by the Florida Department of Citrus looked at whether grapefruit could help with weight loss. The participants were encouraged to eat half a grapefruit with each meal and exercise regularly. The results were encouraging: Several participants lost more than 10 pounds over 12 weeks. Note that the study focused on adding grapefruit to a healthy diet, not adopting a normal grapefruit diet. However, several people report short-term success with the diet, but maintaining long-term weight loss still requires adopting a healthy lifestyle.