Unlike its name suggests, the grapefruit diet is not a 10-day diet of eating nothing but grapefruit. Variations of this diet have existed since the 1930s and have circulated consistently through word of mouth, various books, internet forums and personal testimonials. Strictly speaking, the grapefruit diet is a crash diet and cannot be attributed definitively to any one person.
The gist of the grapefruit diet states that a key ingredient in grapefruit, when eaten in quantity with modest amounts of protein and low-carbohydrate vegetables promotes fat loss. Some variations of this diet allow for grapefruit juice to be substituted for the actual fruit, but the emphasis is that it must not be sweetened. Other acceptable fluids in the diet include black coffee and at least 64 ounces (half a gallon) of water per day. Starchy vegetables such as beans, potatoes, corn and peas are not permitted. When all the permissible foods and liquids are added up it tallies up to between 600 to 1000 calories per day on average. Grapefruit or no, people will lose weight on such calorie restriction.
Beyond its mythical and yet undiscovered fat burning compound, science does have some positive things to say about the grapefruit. First, it is low on the glycemic index and is high in fiber. The combination may help reduce the total number of calories consumed in a meal as a person feels more sated, and when eaten in conjunction with other foods low in the index prevents a spike in insulin production. Lower insulin levels are associated with less fat production. Therefore, periodically eating grapefruit as a way to increase fiber and decrease calories in meals may yield a weight-loss benefit.
Most if not all dietitians recognize the grapefruit diet as a fad diet, and have long since proven its long-term sustainability for several reasons. First, the severe calorie restriction lends itself to binge eating when the diet is terminated. Second, the list of acceptable foods is so limited that a bored palate will tempt the dieter with more succulent foods and undo the diet. Third, the majority of weight loss experienced by dieters on this plan is fluid loss, which returns with regular eating. Lastly, this diet provides no transition to a sensible eating plan when optimum weight is achieved, leading to the eventual unraveling of any results achieved on the grapefruit diet. This diet is effectively known as the Hollywood Diet, and is useful for losing a few extra pounds that won’t be shed for long. If searching for lasting weight loss, incorporate grapefruit into your diet but leave the grapefruit diet alone.