The Grapefruit Diet (a.k.a. the Hollywood Diet), introduced during the 1930s, is one of the oldest fad diets. It's one of those fad diets (like all of them!) that are just too good to be true. Through a combination of fatty meat, grapefruits and grapefruit juice, the Grapefruit Diet allegedly burns fat at high rate. The diet also includes limiting grains, fruit and vegetables. Sound risky? It is... Advocates of the diet claim that it's a "10 day, 10 pounds off diet," but studies have shown it's not only unhealthy, it's also dangerous. Also, can you really picture yourself eating grapefruit all the time, every day of your life? It's just not a realistic regimen for most people.
At least we were able to retrieve a grain of truth from the hysteria. Research by the Scripps team found that obese people who added grapefruit to their diets were able to lose more weight than those who didn't. It was discovered that grapefruit helped people manage their insulin levels, which is good news for diabetics looking for healthy food options. However, it is very important to note that the test group was on a well-balanced diet when they added grapefruit to their meals. They were not on the highly dubious no-vegetable, no-carb diet described above. Which goes to show you that adding fruit to your diet can sometimes lead to pleasant, unexpected results, and that fad diets can never equal a healthy, balanced diet.
 Scott, Jennifer R. (2008-11-10). "What You Need to Know About The Mayo Clinic Diet". About.com: Weight Loss. About.com. Retrieved 2009-03-25.