Food combining

Food combining is the term for an unproven nutritional approach that focuses less upon the quantity and kind of food consumed, and more upon the timing of their consumption. For example, advocates sometimes recommend that carbohydrates and citrus fruits should not be consumed at the same meal, claiming that the enzyme that digests carbohydrates (amylase) can only function in an alkaline environment.

Many of the assumptions used to justify food combining are not supported by biological and medical science, and there is currently little evidence supporting real-world success for these theories. One randomized controlled trial has been reported in the peer-reviewed medical literature, which found no evidence that food-combining principles were effective in promoting weight loss.

History
William Howard Hay introduced food combining to United States in 1911. His approach was based upon the ideas current at the time regarding the alkalinity required to digest the food in the stomach and the pH of food itself. Herbert M. Shelton also contributed a food classification based on the type of nutrients in products. Shelton categorized foods into three groups&mdash;protein products, carbohydrate products and "neutral" products&mdash;and recommended eating proteins and carbohydrates at separate meals.