The Never-Ending Diet Wars

We know this is true because instead of just measuring risk factors like HDL, we measured what actually happens to the progression of coronary heart disease in people who went on diets that were very low in "garbage"—i.e., very low in cholesterol, saturated fat, total fat and refined carbohydrates and high in fruits, vegetables, whole grains, legumes and soy products.

Their HDL levels came down by 9 percent after one year, but their LDL ("bad") cholesterol levels came down even more, by an average of 40 percent.  None of these patients was taking cholesterol-lowering drugs. As mentioned above, even though their HDL levels decreased, these patients showed reversal of their heart disease using state-of-the-art measures.

A low HDL in the context of a healthy low-fat diet has a very different prognostic significance than a low HDL in someone eating a high-fat, high-cholesterol diet. People living in countries such as Asia that consume a low-fat diet have low HDL levels yet among the lowest rates of heart disease in the world.

It's time to call a truce in the diet wars. Although many people feel more bewildered than ever when they hear seemingly contradictory advice about different diets, there is actually a convergence of recommendations that is evolving. While some significant differences remain, a greater consensus is emerging among nutrition experts than most people realize.

An optimal diet is one that is low in fat (because fat, whatever the type, has 9 calories per gram versus only 4 calories per gram for protein and carbohydrates). When you eat less fat, you consume fewer calories without having to eat less food, because the food is less dense in calories, as well as low in refined carbohydrates.

Also, an optimal diet is low in refined carbohydrates. When you remove fiber and bran, you turn an unrefined carbohydrate into a refined one. The fiber and bran fill you up before you consume too many calories—you can only eat so many apples without getting full—but you can consume virtually unlimited amounts of refined carbohydrates such as sugar without getting full. And because refined carbohydrates are absorbed quickly, they cause blood glucose levels to spike which, in turn, leads to repeated insulin surges and, over time, may lead to insulin resistance diabetes.

Whole grains are rich in fiber which slows the absorption of food, causing blood glucose levels to be more stable and actually reducing the incidence of diabetes. Unfortunately, many studies of "low-fat diets" are often very high in refined carbohydrates.  It's low in trans fatty acids and saturated fats and with enough fish oil to provide the good fats of omega-3 fatty acids.

People have a spectrum of choices. To the degree that you eat a diet higher in fruits, vegetables, whole (unrefined) grains, legumes, soy products, some fatty fish like salmon, low in fat, low in refined carbohydrates and served with love, you're likely to look better, feel better, lose weight and gain health.

Disclaimer: I lecture and write books on the benefits of healthy low-fat diets, including my newest book, "The Spectrum," (Ballantine) but I do not endorse or receive royalties from any products other than books.

© 2008