With all the recent emphasis on the importance of watching fat in our diet, it didn't take long for food manufacturers to catch on that we are suckers for anything -- as long as it has no fat. We got fat-free ice cream, baked tortilla chips, muffins, reduced-fat cookies and more. But in 1986 the average weight of Americans ages 25 to 30 was 161 pounds, and in 1996 it was 171. One-third of Americans are considered overweight, and extra calories from nonfat sources is undoubtedly a factor.

So perhaps the message that eating less fat automatically leads to weight control was only a partial truth. Fat has more calories per gram than protein or carbohydrates, so eating less of it will trim calories, but a large bowl of nonfat frozen yogurt may have the same number of calories as a full-fat chocolate brownie. And total calories is what ultimately matters.

The latest National Health and Nutrition Examination Survey showed that adults increased their caloric intake from 1,969 calories in 1978 to 2,200 in 1990. Simultaneously, a survey conducted by the U.S. Department of Agriculture showed that fat consumption dropped from 40 percent of calories in 1978 to 33 percent in 1995. You may choose 90 calories of fat-free honey over a 50-calorie pat of butter on your toast, but extra calories will still end up plumping up your fat cells. Foods that are naturally low in fat, such as fruits, vegetables and grains, also tend to be low in calories. But that's not always true for foods manufactured to be low-fat. To make up for lost taste and texture, manufacturers often compensate by adding extra sugar or protein -- calories that might not be there in a higher-fat counterpart.