or many years the nutritional buzzword was "low-fat." Now it seems that all we hear about is "low-carb" and "high-protein." Low-fat and fat-free grocery items that were once revered are now shunned, along with the whole concept of a diet that is low in fat overall. So what ever happened to the principles of low-fat eating, and just how much fat should we consume as part of our ever-changing diets?

Low-fat is a simple response to a complicated issue. We know so much more about fats today than we did in the 1980s when fat first became widely vilified. There are many different types of fats found in food (see A Chat About Fat). Some fats, like monounsaturated and omega-3 fats, help to promote health. Other types of fats--specifically saturated, hydrogenated, partially hydrogenated, and trans fats - can increase the risk of several diseases. People who emphasize healthy fats and keep unhealthy fats to a minimum in their diets tend to have lower rates of atherosclerosis, heart attacks, diabetes, and strokes. New research indicates that this practice may have anti-cancer effects, too.

This means that the way we used to understand "low-fat" has shifted to mean that only certain fats should be avoided and that we actually need to seek out foods that contain other types of fats. For instance, take a look at the fat-free cookies and reduced-fat crackers that we used to live on. While research does not support the idea that eating reduced-fat and fat-free versions of products will help lower calorie consumption or body weight, there is plenty of evidence that a diet that is low in total fat does aid in weight loss. These items can be part of your overall low-fat diet, but every food you eat should not be low in fat. Another important point about these foods is that both the regular and reduced-fat versions are often made with hydrogenated, partially hydrogenated, or tropical oils (palm and coconut oils). These are some of the most dangerous fats in our diet. The ideal thing to do is to choose cookies, whole-grain crackers, and other snack foods that do not use these unhealthy fats and just limit your portion sizes. Another strategy that researchers have found useful is to concentrate on eating more vegetables, fruits, and whole grains while eating less meat and junk food and to replace fats used for cooking, like butter, and other added fats with olive oil. Check out the fat charts on the facing page to see what you should be adding and subtracting from your current diet.

As always, moderation is the key. Very low-fat and virtually fat-free diets are potentially dangerous since they can increase the risk of essential fatty acid deficiency (some fat is required for normal bodily function). Also, when fat is removed it could be replaced by carbohydrates in the diet. A diet that derives 70 or 80% of calories from carbohydrates may increase blood triglyceride levels, a risk factor for heart disease. On the opposite end of the spectrum, a high-fat diet is very high in calories since fat contains 9 calories per gram (carbohydrates and protein each have 4 calories per gram). The calories can add up quickly and lead to obesity; a huge risk factor for heart disease, diabetes, and cancer (otherwise you'd have to exercise a lot to compensate for the extra calories). Furthermore, eating lots of fat leaves little room for all the vegetables, fruits, whole grains, and protein that our bodies require to prevent deficiencies and diseases.

A moderate, healthy amount of fat is considered 30% of calories from fat, or 60 grams for a 2000-calorie diet. No more than 10% of calories should come from saturated and trans fats combined. Most men require between 2000 and 2500 calories per day, and most women require between 1500 and 2000 calories a day, depending on their age, size, and activity level. It is currently estimated that men are eating between 35 and 44% of their calories from fat and women are eating between 31 and 40% of their calories from fat, and much of it is saturated and trans fat. Not only do most of us need to adjust the total amount of fat we eat, but also the ratios of healthy and unhealthy fats. Use the information in A Chat About Fat and the fat source tables to help yourself make these necessary changes in your healthy "low-fat" diet.