The notion that you should eat fruit only on an empty stomach is a persistent myth that has been circulating online for years. Supposedly, if you eat fruit along with other foods, you won’t be able to digest it; instead, it will stay in your stomach and rot. This is nonsense. Fruit may digest more quickly if you eat it on an empty stomach, but it certainly won’t rot if it is sharing space with other food. Rotting represents decomposition by microorganisms, few of which can live on the strongly acidic environment of the stomach.
Related myths are that eating fruit along with other foods will cause gas, bloating, weight gain, gray hair, balding, nervous breakdowns and dark circles under the eyes. I’ve seen claims that eating fruit on an empty stomach will prevent – or cure – cancer as well as detoxify your system and energize you. There is absolutely no scientific basis for any of this.
The nutritional value of fruit is the same regardless of when you eat it. The only people who may have to be careful about which fruits they eat and when and how often to eat them are those with diabetes. If you take a look at the glycemic index (GI), a measure of how fast carbohydrate foods (which include fruits) are converted in the body to blood glucose, you’ll see that there are big differences among fruits. I recommend choosing ones that rank low on the glycemic index (those that score below 55). Generally, temperate fruits like berries and apples score lower than tropical ones like mangos and pineapples. How quickly fruit will raise blood sugar depends on whether you eat the fruit after a high-fat meal or drink it as a glass of fruit juice on an empty stomach. You’ll also want to consider what your blood-sugar level is when you eat the fruit. It is also important to pay attention to the amount of fruit you eat – choose a small or medium-sized apple over a large one (or eat only half of the large one).
Mother Nature clearly intended us to eat fruit to help disperse seeds. Fruit offers quick energy, as well as vitamins, minerals, fiber, antioxidant pigments and other protective compounds that reduce risks of disease. My anti-inflammatory diet calls for 3 to 4 servings per day of fresh, seasonal, or frozen fruit, organic whenever possible. Eat it with meals or between them. Your personal preference is all that matters.
Andrew Weil, M.D.