Glycemic Index

The general measure of how much your blood sugar increases after eating specific carbohydrates is called the glycemic index (GI). This is associated with the amount of insulin produced. The GI is a general measure of individual responses to particular carbohydrate foods; however, individual variation is not considered in studies of foods and their glycemic effects.

High-GI foods, which produce the greatest glucose response (and highest insulin), include bagels, breads, potatoes, sweets, and other foods that contain refined flour and sugar. Many processed cereals, especially those containing malt sugars (maple syrup, maltose, maltodextrin, etc.), have a very high GI. Even foods you may think are good for you can trigger high amounts of insulin, including fruit juice and large bananas, especially when unripe. The biggest problems in most diets may be wheat products, potatoes, fruit juice, and sugar or sugar-containing products. Most sports drinks, energy bars, and other carbohydrate-based products are very high glycemic; they can be useful during training or competition when insulin levels are much lower but not as a regular part of an athlete’s diet.

广告：个人专属 VPN，独立 IP，无限流量，多机房切换，还可以屏蔽广告和恶意软件，每月最低仅 5 美元

Carbohydrates with a moderate and low GI include many fruits, such as apples, peaches, pears, grapefruits, and cherries, as well as legumes such as lentils. Non-carbohydrate foods—proteins and fats—usually don’t cause a glycemic problem, although in some people even meals high in protein can trigger an abnormal insulin response.

Eating smaller and more frequent moderate- and low-glycemic meals often reduces high insulin production, as discussed later under healthy snacking. Most vegetables contain only small amounts of carbohydrates—except very starchy ones like potatoes and corn. Carrots were at one time believed to be a high-glycemic food, but studies have shown the glycemic effect of this root vegetable to be much lower than previously thought.

In practical terms, this means that eating refined foods like a large cookie or piece of cake will cause more problems than eating a piece of fruit or whole-grain cracker with the same amount of carbohydrates and calories. Low-fat foods or low-fat meals containing carbohydrates have a relatively higher glycemic index because digestion and absorption of sugar are quicker when less fat is present. Eating carbohydrate foods in combination with some fats, such as olive oil or butter, slows digestion and absorption, thus moderating the insulin response. Moderate protein levels in a meal also can lower the glycemic index of the meal, as can fiber.

By moderating carbohydrate intake to control insulin production, you can increase your ability to burn fat as an optimal and efficient source of almost unlimited energy. Rather than using the glycemic index as a guide, which has become common, it may be best for athletes to learn which foods and food combinations work best for their individual needs.