High times for low-carb: can you really eat yourself thin? How does the latest diet craze affect your health—and the pleasure of mealtime? - Healthy Appetites

Natural Health, March, 2004 by Janis Jibrin

Move over, low fat! From ice cream (Breyers) to ketchup (Heinz) to bread (Arnold's) to beer (Michelob), low-carb products are raring to take your place. There are even entire stores specializing in low-carb fare. For example, Castus, a self-described "Low-carb Superstore," sells about 1,600 products. The company has six West Coast locations, but expects to eventually have 5,000 outlets open over the next five years.

Unlike "low fat," which has earned a carefully hammered-out legal definition by the Food and Drug Administration, there is no such standard for "low carbohydrate." And the FDA is taking notice.

"We are taking legal action against one manufacturer because of a misleading label," says Lester Crawford, D.V.M, Ph.D., deputy director of the FDA. The product in question claims to be low-carbohydrate, but it contains mostly carbs.

Most low-carb products, however, are indeed lower in carbohydrates than their regular counterparts. How do they do it? Instead of sugar and wheat flour, low-carb muffins, pancakes, cookies, pastas and other starch substitutes are made from high-protein ingredients such as soy or wheat gluten. If they contain a carbohydrate, it's usually oat bran, wheat bran or inulin. (The latter, a fiber-like substance, is a prebiotic, meaning it encourages the formation of healthy, beneficial bacteria in the intestine.) The body can't break down these carbs, so they pass through the digestive system and contribute far fewer calories than digestible carbs.

a question of taste

Chucking out ingredients that have stood the test of time and developing tasty products in their stead is tricky business. That's because flour and sugar contribute not only taste but "mouthfeel," which refers to the moistness, tenderness, texture and structure we've come to expect in food, especially baked goods.

"It's hit or miss with many of these foods," admits Diane Schwartz, marketing director of Castus. Of the low-carb options, Schwartz loves the chocolates and likes many of the chips and the pancake and muffin mixes, but she finds the pastas and ready-to-eat muffins can be disappointing.

Others are less impressed overall. "The low-carb products I've tasted don't do anything for me, which might be a good thing if you're trying to lose weight," quips Julie Jones, Ph.D., professor of food and nutrition at the College of St. Catherine in St. Paul, Minn.

nutritional give and take

Some low-carb ingredients are vast improvements nutritionally over the sugar-heavy, fiber- and nutrient-poor makeup of the low-fat foods that became so popular in the last decade. For instance, 25 grams of soy protein can help lower cholesterol in the context of a low-fat diet, and one serving of low-carb pasta can provide about a quarter of that amount. Also, oat, wheat and rice brans are excellent sources of fiber, which is linked to a lowered risk for heart disease, certain types of cancer, diabetes and obesity.

Because low-carb foods are usually sweetened with calorie-free artificial sweeteners, they don't contain empty sugar calories. Even those sweetened with sugar alcohols, such as lactitol (a derivative from the milk sugar lactose) and maltitol (from malt), deliver only about half the calories of sugar. In moderation, sugar alcohols are fine. "But watch it; eat too much and you'll wind up with diarrhea," warns Jones.

While there are many healthful low-carb foods, loads of low-carb junk food is also available. Just as sugar replaced fat in the old low-fat snacks, fat is replacing carbs in many low-carb products. Some are alarmingly high in artery-clogging saturated fat. For example, an Atkins Advantage Chocolate Coconut energy bar racks up 8 grams of saturated fat, about half a day's recommended limit for saturated fat.

the proof isn't in the pudding

Publicity aside, the scientific evidence that low-carb diets work is sparse and mixed. One study published in the New England Journal of Medicine found that after six months, low-carb dieters lost more weight than those on low-fat diets. But another study in the same journal found no significant difference in weight loss between low-carb and high-carb dieters after one year.

"The low-carb group was eating, on average, 460 fewer calories per day than when they came into the study compared to just 270 calories less for the high-carb group," explains Frederick Samaha, M.D., assistant professor of medicine and chief of cardiology at the Philadelphia Veterans Administration Hospital, who led the year-long investigation.

The restrictive nature of the low-carb diet may explain the calorie disparity. It's not known whether dieters trying to add more variety to their menu by taking advantage of the rapidly expanding number of low-carb foods will be encouraged to eat greater amounts of food, thereby consuming more calories.

"Low-carb products are valuable if they help people drop calories, because that's what it takes to lose weight," says Samaha. "But if people substitute low-carb beer and candy for broccoli, it's not going to get them anywhere."