Let’s face it. We see “low-fat” on a label and throw the product into our shopping cart, thinking we have found the healthier option. Walter Willett, author of EAT, DRINK, AND BE HEALTHY, tells us why low-fat products are not the best choice.
A common though absolutely false thread that runs through many diets is the idea that fat in food makes fat in the body. Limit “fat calories,” so the thinking goes, and you’ll be able to control your weight. Although there’s a pleasant symmetry to that logic, there’s no good evidence linking dietary fat with excess weight. In fact, there’s plenty of evidence showing that a higher percentage of calories from fat doesn’t lead to gaining weight or being overweight and the evidence is tending in the opposite direction.
That’s why the Harvard Healthy Eating Pyramid and Healthy Eating Plate don’t ban fats. Instead, they treat fats as important nutritional factors in your diet. I cover what fats to choose and how much to eat in chapter five.
To be sure, some countries with high fat intake have many overweight people. In the United States, for example, the average person gets about one-third of his or her daily calories from fat (a relatively high percentage), and almost two-thirds of the population is overweight or obese. But not long ago in parts of South Africa, where 60 percent of people were overweight, fat contributed barely one-quarter of calories. In other words, factors other than dietary fat influence overweight and obesity.
I am not trying to absolve dietary fat or downplay its potential contributions to weight or weight gain. Dietary fat affects energy, fat stores, and weight. But there is no evidence that calories from fat contribute more to weight gain than calories from carbohydrates or other sources.
But if you balance the number of calories you eat with the number of calories you burn, especially if part of the burn comes from exercise, then you won’t gain weight on a diet that has 35 percent, 40 percent, or more calories from fat. And if you are eating the right kinds of fat, you will help protect your- self from heart disease and other chronic conditions.
Check out a common myth of low-fat diets.