In a magazine ad for milk, actress Stockard Channing holds a glass of the white beverage while a printed message below extols milk's ability to "help you burn fat and lose more weight than cutting calories alone."

Milk is one of a slew of foods and beverages that have begun claiming special properties that their marketers say can help us shed pounds. Among them: yogurt, eggs, oranges and a brand of bottled water.

Is it true? Can these foods help make you svelte? In a nation where battling the bulge is an endless occupation, plenty of dieters would like to know.

We asked a Seattle-based nutrition expert with a national reputation to give us her take on these claims. Her conclusion: Some of these foods appear to help, but none is a magic bullet.

Our expert: registered dietitian Kathleen Mahan, co-author of the nation's most widely used college nutrition textbook, "Food, Nutrition, and Diet Therapy," which has been translated into four languages and which she updates every four years. She also lectures on nutrition at the University of Washington and has a nutrition-counseling practice, Nutrition by Design.

Here's a sampling of claims, along with Mahan's comments.

Milk and yogurt

Those "burn fat and lose more weight" ads for milk — sponsored by the milk-processing industry — and similar promotions for some yogurt brands are linked to weight-loss studies involving dairy products and calcium.

One of the most recent was conducted by researchers at the University of Tennessee and published last December in the journal Obesity Research. The National Dairy Council provided funding.

When the researchers tested three reduced-calorie diets on 32 obese adults, they found that those who followed a diet high in dairy foods not only lost the most weight but also lost more of it as abdominal fat. Second in weight loss were those who took calcium supplements, while a third group, on a low-calcium diet, lost the least weight.

Researchers tentatively credited the calcium in milk and/or the vitamin D added to most milk for the better showing by the high-dairy group, though they said further studies are needed to pinpint the precise reasons for the difference. Other research also has pointed to calcium as assisting weight loss.

Mahan said adding dairy foods to a weight-loss diet isn't a bad idea as long as they are low-fat or fat-free dairy products, such as milk, yogurt and cheese. Besides the calcium and vitamin D, you'll get high-quality protein, she said.

Participants in the high-dairy section of the University of Tennessee study consumed about 1,137 milligrams of calcium daily.

As a guide, Mahan said, you'll get 1,200 milligrams of calcium from four 8-ounce cups of milk or from a quart of yogurt (or four pint-size cartons).

Calcium is also found in some plant foods, such as broccoli and spinach and in some tofu (check the nutritional label).

Oranges

"Not only are oranges low in calories, they are high in water and fiber, which research shows can suppress hunger and increase fullness," boasts promotional material from Sunkist Growers, a huge citrus-marketing cooperative.

The claim has validity, said Mahan. Oranges' high water and fiber content can indeed help you feel full at a relatively low cost in calories (about 100 per large orange). Oranges also supply lots of vitamin C, assorted carotonoids and a fair amount of potassium. Whole oranges beat orange juice, in which calories are more concentrated.

Despite oranges' benefits, however, you can't overload on other foods and expect oranges to make you skinny. Their weight-control asset, after all, is supposed to be in helping prevent too much eating overall.

Also: Oranges are far from alone among fruits in supplying water and fiber along with vitamins and minerals and relatively modest calories levels. Among the many: watermelon, cantaloupe, grapefruit, blueberries, raspberries, blackberries, peaches, nectarines, apricots, apples, pears. Experts advocate variety, for a wider range of nutrients.

Bottled water

The Fiji brand of bottled water is a relatively expensive brand. Its producers say it is extracted from an aquifer on the main island of Fiji, and they claim it to be "the ultimate weight-loss tool."

"The key to long-term, permanent weight loss is very simple — drink eight glasses of water a day — Fiji Water," Fiji spokeswoman Desiree Gallas has written.

"If you do nothing more than drink eight glass of Fiji Water a day, you'll be able to shed pounds and keep them off without sacrificing all your favorite foods," said a promotional e-mail from Gallas.

Fiji also says that "because the brain cannot differentiate between hunger and thirst, more often than not, perceived hunger pains can be staved off by one of the recommended eight glasses of water."

True? Mahan said studies indicate that the body can indeed confuse thirst with hunger and that drinking a glass of water may help you feel full and stop you from indulging in an unneeded snack. But she said tap water would do this as well as any brand of bottled water.

Eggs

Seattle times file photo

"Eggs may help in weight loss!" declares a headline on an egg-promoting Web site maintained by the Canadian Egg Marketing Agency.

The site says new research at the University of Illinois indicates "quality protein, such as the protein found in eggs, can aid weight loss. This research shows that the essential amino acid leucine (found in eggs) helps to reduce loss of muscle tissue, promote loss of body fat and stabilize blood glucose (sugar) levels."

The research, published in the Journal of the American College of Nutrition, was supported by the Illinois Council on Food and Agriculture Research, Kraft Foods, the Cattlemen's Beef Board and the National Cattlemen's Beef Association.

The research does suggest this, said Mahan, but eggs are far from the only protein food containing the amino acid leucine, a component of protein. In fact, nutritional data from the U.S. Department of Agriculture indicates that 3 ounces of tuna, beef, salmon or chicken, for example, all contain more leucine than that found in a single egg. Even a cup of nonfat milk or a half-cup of tofu contains more leucine than an egg.

Protein sources used in the UI weight-loss study were not limited to eggs but also included meat and dairy products. The research was part of a growing array of studies looking at higher-protein, lower-carbohydrate diets and weight loss.

In the 10-week study, women on the higher-protein diet generally lost more weight, more body fat and less lean mass than women in the higher-carbohydrate group, researchers found. Increased leucine was detected in the blood of the higher-protein group, suggesting a connection to the greater weight-loss success.

The scientists also said their research suggested that high-quality protein at breakfast, in particular, may promote more weight loss when part of a higher-protein diet.

Mahan said this fits with her own experience with weight-loss dieters.

"A higher-protein breakfast does appear to be helpful," she said. "But it doesn't have to be eggs, which contain (potentially artery-clogging) saturated fat. It could be other, lower-fat protein sources." And limited carbohydrates are fine, too.

She suggested these low-fat sources for breakfast protein: three or four links of very lean turkey sausage, or "lots of lox" on half a bagel. Low-fat cottage cheese, fruit and a small piece of toast are another breakfast possibility.

Eggs are OK, too, Mahan said, but in moderation because of their saturated fat.

Judith Blake: jblake@seattletimes.com