Our supermarkets are stocked full of non-fat and low-fat food products: one percent milk; non-fat milk; "light" ice cream; non-fat salad dressings, lean meats, diet sodas, low-fat soups.

Yet every year, Americans grow more and more overweight. According to the Institute for Nutritional Health in New York, 55 percent of all adults in this country are overweight. More than 300,000 Americans die every year from obesity-related diseases. If the trend continues, experts predict, within a few generations, virtually every American adult will be medically overweight.

What''s going on? If we''re eating more low-fat and non-fat foods, why are we still getting fatter?

It may be, local nutritionists suggest, that people are focusing too heavily on fats alone. Judi Brooks, Ph.D, a clinical dietician at Community Hospital of the Monterey Peninsula who also teaches at Monterey Peninsula College, says that while the percentage of fat in people''s diets is on the decline, people''s overall calorie consumption is actually increasing. "We''re actually eating more," she points out.

That''s partly because, she explains, eating fat makes you feel full. And when you don''t get enough fat in your diet, you feel hungry, so you eat more. "Fat is satisfying in the mouth and pleasant to the taste," she says. "It gives you a feeling of fullness for a longer time. If people would put fat back in their diets, they''d feel satiated sooner."

When people deny themselves a satisfying food, like a candy bar, and replace it with a non-fat food that doesn''t satisfy their craving, they usually end up eating other foods to compensate. As Brooks tells her weight reduction classes; "You tell yourself, I can''t have this candy bar. So you eat the non-fat item, and it''s not enough. So you eat more, and more and more. You ''eat around'' the candy bar, and then you end up eating the candy bar later, anyway."

And there''s a deceptive aspect to eating, say, low-fat ice cream. "If I choose a low-fat food, it gives me license to eat more," Brooks says, mimicking how dieters rationalize their "cheating." Why not have two servings of ice cream instead of one--it''s low-fat, right?

"Look at some of those foods carefully," cautions Sandy Silva, a registered dietician at Natividad Medical Center. "They may be lower in fat, but not lower in calories.

"A calorie is a calorie," Brooks says. Fat gives food its flavor, she explains. In order to replace that flavor, manufacturers of low-fat foods often add salt and sugar. The cookie is still low-fat, but it may be loaded down with sugar calories. "People may think, I can eat that, it''s fat-free," she says. "A bagel is fat-free. But it can weigh five ounces, which is equal to five slices of bread. People are not paying attention to the fact that they''re eating 400 calories of starch in that bagel, plus whatever they put on it."

Limiting fat intake is important for more than just weight control. It''s a health issue, as well. Leading health organizations including the American Heart Association, the American Cancer Society, and the American Dietetic Association all urge people to decrease their fat intake as a key step toward good health.

But saying no to fat is hard, probably the hardest kind of food foible to control, says Silva. "It''s a big part of the American diet," she says. "When you''re driving along, there''s always a McDonald''s. They''re not really promoting carrot sticks."

It''s now recommended, Silva says, that 30 percent of our daily calories come from fat. No more than 10 percent of that should come from saturated fats. In the attempt to keep fat consumption down, shoppers eagerly seize upon every new product with the catchy "fat free" label.

One of those new products is Olestra, a fat substitute that first appeared on the market last summer in certain "savory snacks," such as potato chips. Dieters cheered its debut, convinced they could munch away happily on bag after bag of salty chips with nary a fat care in the world.

On the one hand, the American Dietetic Association has given the green light to Olestra, writing, "Fat replacers like Olestra are one of the many acceptable ways to help reduce the amount of fat and calories in one''s diet." The American Medical Association notes that 150 studies, including 43 clinical trials, have been conducted on Olestra, making it "one of the most thoroughly tested foodstuffs to come to market in America."

Procter & Gamble, which markets Olestra under the brand name Olean, and uses it mainly in potato chips, notes that a one-ounce serving of its potato chips contains no fat and just 75 calories, compared to 10 grams of fat and 150 calories in regular chips. "If everything in the average snacker''s diet stays the same, except that Olean snacks are substituted for full-fat snacks, the individual will avoid eating eight pounds of fat in just one year," Procter & Gamble states on its Olestra Website.

On the other hand, Silva and Brooks caution, Olestra is not without its side effects. Olestra products carry an FDA warning, Silva says, noting that consumption can cause abdominal cramping and diarrhea. "Olestra is still out there," Brooks says. "Still, there''s a lot of debate over whether it''s safe or not."

It might also lead to vitamin depletion. Fat in the diet serves an important function, transporting vitamins A, D, E and K into the body and then allowing the body to absorb them. Olestra, on the other hand, binds those vitamins together and causes them to be excreted by the body, instead of being absorbed and utilized. Companies using Olestra in their snack foods have had to fortify their products with extra fat-soluble vitamins in order to be allowed to sell them, Brooks notes.

The long-term effects of ingesting fat replacers are still unknown, she adds. "It''s the same thing with artificial sweeteners," she says. "We''re a generation that''s doing ''research'' on ourselves. And if we''re feeding these substitutes to our children, what''s the effect over a lifetime?

Products like Olean, which promise guilt-free indulging, "give us license to continue habits, instead of changing behavior," Brooks warns.

In fact, Silva says, the initial burst of interest in Olestra snacks seems to have tapered off. "It seems like it''s kind of dropped," she says. "Maybe people didn''t like the products, I don''t know. I wouldn''t recommend Olestra products. But if someone wanted to eat them, I wouldn''t say, ''They''re poison.''"

So what''s the answer? "Moderation is the key," says Silva. "Get a variety of foods." Monitoring fat content is certainly important, she says. Choose low-fat or non-fat milk over whole milk, for yourself and all children over the age of two. "A lot of times, you can substitute in recipes," she notes. "Use non-fat sour cream instead of regular."

Don''t go overboard, Brooks cautions. If choosing low-fat foods rather than the less satisfying non-fat varieties means you''ll stick to healthier eating habits, then that''s what you should do. "If we eat what we want and stop when we''re satisfied, no one would have weight problems."

Ain''t that the truth?

Pass the potato chips. cw