Carbohydrate counting is an extension of the use of exchange lists in which individuals keep track of the amount of carbohydrate they consume and adjust their insulin dosages accordingly. A new and much more effective approach began with research studies in the early 1980s that eliminated exchange lists and focused on selecting foods to make postprandial sugar absorption more gradual and improve insulin function. Fat promotes insulin resistance. Sugar builds up in the blood, and insulin cannot do much about it. Reducing dietary fat is a very powerful step, and one that the exchange lists do not take full advantage of, because they traditionally call for a relatively liberal fat intake, including butter, meat, oils, and other fatty foods.
Complex carbohydrates release their sugars gradually .
The starchy part of beans, vegetables, and grains is complex carbohydrate , natural sugars that are chemically linked together in a chain. During digestion, these sugars gradually come apart and pass into the blood a bit at a time, rather than all at once. The body can then use these natural sugars for energy. On the other hand, table sugar, candy bars, and sodas release sugar that is absorbed into the bloodstream abruptly. The same is true for some fruits.