(6 of 7)
If we were to start from scratch, how would we design a diet to keep our weight under control? For starters, we could concentrate on diets geared for life rather than quick and easy weight loss. "The people I see are great dieters, beautiful dieters," says Dr. Cheryle Hart, founder and medical director of the Wellness Workshop in Spokane, Wash. "They can deny themselves, but only for so long. Then they snap. We all would." Second, we could stop paying such close attention to every jot and tittle in the diet debate. It will take decades for researchers to unravel all the reasons we eat what we do, and why we like to eat so much of it. But a few insights are emerging that should point us in the right direction, as long as we don't turn them into inviolable dietary laws.
Not all carbohydrates seem to have been created equal. So-called simple carbohydrates, those found in white bread and cake, are so quickly digested by the body that they trigger a very rapid rise in the levels of glucose in the blood. The pancreas releases a massive amount of insulin to mop up the excess. Soon enough, however, blood glucose levels plummet to the point where our brains may feel woozy, we become excessively hungry and are driven to eat again. Complex carbohydrates, on the other hand, particularly those rich in fiber, do not elicit the same kind of spike-and-crash response.
Researchers refer to the amount of glucose a single serving of a particular food releases in the bloodstream as its glycemic load. And there is growing evidence that we can manipulate it somewhat to control our hunger. Broccoli and peanuts, for example, have a low glycemic load, while instant rice and baked potatoes have an extremely high one. Avoiding sugar-laden processed foods and increasing the consumption of fruits and vegetables is a first step toward sensible eating, says Dr. David Ludwig, director of the Optimal Weight for Life Program at Children's Hospital Boston. Choosing small portions of pasta and bread made from coarsely ground wheat is a good second step.
Dairy products and milk--which has been increasingly replaced by soft drinks in the diets of both children and adults--are also fast emerging as dietary "goods," despite the fact that a 12-oz. glass of skim milk has almost as many calories as a 12-oz. can of Coke. The reason may have to do with calcium, says Michael Zemel, professor of nutrition at the University of Tennessee. In the absence of calcium, levels of the hormone calcitriol increase. Among other things, calcitriol shuts off the mechanisms that break down fat and activates those that make it.
Fats too are gaining new respect. Olives, nuts, avocados and other foods that are rich in mono- and polyunsaturated fat belong in our diets, many nutritionists believe. Not only do these good fats help lower the level of LDL, or bad, cholesterol, but they are also essential for the absorption of fat-soluble vitamins like E.