Why give the WHI diet study credence?(GUEST EDITORIAL)

Counseling and motivating our patients to change their diet and lifestyle are tough enough, but the results from the Women's Health Initiative's examination of low-fat diets are likely to make that job even harder.

The study results, which were reported in three papers published in the Feb. 8 issue of the Journal of the American Medical Association, made headlines around the world. I'm concerned that the way this study was reported may cause many of our patients to throw up their hands and wonder why they are trying so hard to adhere to a way of eating that science says holds no benefit.

Having seen what a powerful difference changes in diet and lifestyle can make, it concerns me that the Women's Health Initiative study may discourage many people from making changes that can be so beneficial to them. That's why it's critically important to understand the limitations of this study and continue to advise our patients about the benefits of low-fat, whole foods nutrition.

The Women's Health Initiative (WHI) study examined the rates of colorectal cancer, heart disease, and stroke in women who followed a low-fat diet, compared with women with normal diets. The researchers reported no statistically significant reductions in any of the diseases.

The study is seriously flawed. If you don't change much, you don't improve much. Given how small the changes in diet were, it's not surprising that there were few effects.

Even if a study of a diet has 49,000 women and spends $450 million, it's not going to show very much if people don't follow the diet. And it's not going to show very much if both groups changed their diet to about the same extent. That's what happened.

The women in the study were asked to reduce their dietary fat to 20% of calories, but they reported reducing it only to 29%. It's unlikely they even did that well, since they reported reducing their caloric intake from 1,700 to 1,500 calories/day, but they didn't lose weight.