There is a diet that encourages eating only fruit before noon. Based on the philosophy of food-combining, "Fit for Life, Not Fat for Life" and was first introduced in the mid-1980s by Harvey and Marilyn Diamond. The book was on the New York Times best-seller list for 40 weeks and had sold 12 million copies back in the '80s.
The plan suggests that from the moment you get up, you can eat as many fruits and drink as much fruit juice as you want. After lunch you can still eat fruit, but are also allowed to eat vegetables combined with either a starch or a protein, both which are considered "dead" foods. Do not eat vegetables with both starch and protein, as the book claims that combining the two is toxic and will make you fat.
The Diamonds says it is important to eat fresh fruit, and choose fruits with a high water content. You can occasionally eat dried fruit, but only naturally dried fruit. Start the day with a glass of water to rinse the digestive tract.
The rules on eating fruit after lunch are more complex. For example, "Once you have eaten something other than fruit, you should wait at least three hours before eating fruit or drinking juice again," Mr. Diamond says on the website eNotAlone.com. After drinking juice, you can eat other foods 10 to 15 minutes later. Wait 30 to 40 minutes after eating a whole fruit or smoothie before eating anything else. Bananas and dried fruits need 40 minutes of digestion. If you want to eat fruit before going to bed, make sure three hours have passed since your last cooked meal, and one and a half to two hours have passed after eating a salads.
Susan Male Smith, a registered dietitian and the editor of Environmental Nutrition, a newsletter for laypeople, is one expert who believes this diet is unhealthy. She said in an New York Times article, "It is potentially dangerous because it tells you to ignore side effects. It tells you not to worry about dehydration.''
Health.com states no clinical studies or anecdotal evidence show this method is effective in either taking off or keeping off the pounds. Furthermore, this site and Smith state that people engaging in this diet are likely to suffer from a calcium deficit, as the plan discourages eating dairy products.