LOW-FAT DIETS: A FAILED EXPERIMENTMost of you know that for the last few decades, the government agencies concerned with health care have beamed forth a strong and unwavering message: reduce your total fat, saturated fat, and cholesterol intake to achieve a healthy weight and decrease your risk of heart disease. The message has been so unrelenting that the terms “healthy” and “low fat” seem inextricably linked, but the rationale for a low-fat diet is based on two overly simplistic ideas that we now understand to be incorrect.
Wrong Idea #1
Because fat contains 9 calories per gram, more than twice the 4 calories per gram of both protein and carbohydrate, the assumption has been that reducing its intake should be the easiest way to promote weight loss. And, so goes the logic, eating less fat should also allow you to eat a greater total volume of food and therefore feel more satisfied. This logic is expressed in the axiom “You are what you eat.” In other words, if you eat fat, you must get fat. The corollary is that if you eat less fat, then you’ll easily lose body fat. Many Americans have embraced this seemingly intuitive strategy hook, line, and sinker, only to fail to lose weight or to maintain weight loss.
Cutting Fat Doesn’t Make Us Thinner
As a nation, our consumption of total fat and saturated fat intake has remained relatively steady and even trended slightly downward over the last two decades. So why are about two-third of adults overweight or obese? And why are we experiencing an epidemic of diabetes? And why has metabolic syndrome become a significant health threat to tens of millions of Americans? Not because we failed to pay attention to dietary recommendations focused on lowering fat. Rather, we replaced fat calories with an abundance of carbohydrate calories, without understanding that many people have a metabolism that cannot process the additional carbs. Basically, the low-fat approach has backfired.
Wrong Idea #2
A second reason for the major emphasis on reducing dietary fat, saturated fat and cholesterol is based on the belief that consuming fatty foods will lead to increased blood cholesterol levels, which, in turn, will increase the incidence of heart disease. This belief system, often called the “diet-heart hypothesis,” has shaped nutrition policy in this country for the last 40 years. But despite decades of research and billions of taxpayer dollars earmarked to prove this hypothesis, there’s little evidence to support its basic premise.
The largest and most expensive study on the role of fat in the diet was the Women’s Health Initiative, in which almost 50,000 women aged 50 to 79 were tracked for an average of eight years. Researchers assigned participants either to a low-fat diet that reduced total fat intake and increased the intake of vegetables, fruits and grains, or to a control group of people who could eat whatever they wanted. Multiple research papers reported on the results of this colossal experiment. A low-fat eating pattern revealed no significant effect on weight loss or the incidence of heart disease, diabetes or cancer. You can see why the low-fat dietary approach to weight control gets a failing grade. Atkins Web Site July 2010