"There's never going to be one particular food that's marketed to help you lose weight that's going to do it. No question about it," Kulze said.
Low-calorie frozen meals are a diet food star. They are great for portion control, but buyers should still be on the lookout.
"Avoid the great white hazards -- these refined carbs, white flour, white rice, white potatoes, sugar," Kulze said.
Grab meals with at least 15 grams of protein. A diet food loser is the liquid lunch. It is a short-term fix for some, but the effects do not last.
"Liquid calories simply do not suppress the human appetite to the same degree of solid food calories," Kulze said.
Low-carb diets need modification to make it on the winner's list.
"Just because something is labeled low carb does not mean it's going to be low in calories or even healthy for you," Kulze said.
Instead of low carb, think right carb. These include fruit, beans and whole grains. Even fat-free foods that were once popular have lost steam.
"The only fat-free food I recommend to anyone -- people that want to lose weight or people that are healthy weight -- is fat-free milk," Kulze said.
Fat free food is often loaded with sugar. A cookie with fat is better than one without because fat slows the body's glucose response, Kulze said.
Another loser is sugar-free food.
"It's probably a classic example of labeling schizophrenia at its finest," Kulze said.
The first ingredient in many types of sugar-free cookies is white flour.
"White flour in the human body is handled exactly like if you sat there and ate sugar out of the bowl," Kulze said.
Even sugar-free soda is risky. One study shows your risk of being overweight rises more than 40 percent with every diet soda you drink
Researchers say even though diet soda has no calories, it tastes sweet. The body expects to receive a corresponding number of calories, and this is likely to cause people to over-eat.
Kulze said stick to whole, natural foods like whole grains, beans and lean meats. Get at least 15 grams of protein and seven grams of fiber in every meal. For example, a half cup of cottage cheese or two eggs and 3/4 of a cup of broccoli does the trick.
Web Extra Information
BACKGROUND: In 2005, Americans spent more than $60 billion on diet foods. Whether it's low-carb, low-fat, sugar-free or those convenient diet frozen meals, you can find diet foods in just about every aisle of the grocery store; but if those diet foods work, then what's the deal behind the 60 percent of Americans who are still overweight? Ann Kulze, M.D., a nutrition expert in Charleston, S.C., says, "There really has been an explosive increase in foods that are labeled and marketed to dieters." But she adds, "There's never going to be one particular food that's marketed to help you lose weight that's going to do it -- no question about it." Here's a breakdown of the most popular diet foods:
LOW-FAT AND FAT-FREE FOODS: Of fat-free foods, Dr. Kulze says, "When you take all the fat out, you have to put something else in there to give it taste. What you see with foods that are marked fat-free or low-fat is that they're loaded with sugar or refined carbs." She calls foods like this "a metabolic torture device." One recent study shows people on a low-fat diet actually gained six pounds while those on a moderate-fat diet lost nine pounds over 18 months. Dr. Kulze says if you want an occasional treat, choose a sweet with fat, rather than one without. Fat will help slow the body's glucose response to the sugar in the sweet, which is better for those watching their weight.
FROZEN MEALS: Dr. Kulze says low-calorie frozen entrees are convenient and they force people to practice portion control. Many of these meals can be worked into a very healthy diet, but Dr. Kulze says beware: they are not all created equal. She says, "I would definitely stay away from frozen entrees that feature or that have pasta and white flour products like bread, potatoes, white rice." She calls these "the great white hazards" as they perpetuate the appetite. Instead, look for meals that contain fiber, non-starchy vegetables and/or whole grains. Also, reach for those that have at least 15 grams of protein to fill you up. Dr. Kulze says, "Protein is nature's diet pill. Protein will satisfy the human appetite longer than any of the other macronutrients."
SUGAR-FREE FOODS: Dr. Kulze says sugar-free foods are "a classic example of labeling schizophrenia at its finest." For example, if you look at the ingredients on most sugar-free cookies lining the shelves, you'll find white flour as the first ingredient. "White flour in the human body is handled exactly like if you sat there and ate sugar out of the bowl." In fact, if one serving of sugar-free cookies contains 24 grams of carbohydrates, that's equal to five teaspoons of sugar! So nix those sugar-free traps, and choose healthy whole foods instead.
DRINKING YOUR MEALS: Liquid meal replacements are quickly becoming a "has-been" in the diet world. One reason says Dr. Kulze, "They are so boring. They completely take all of the joy out of eating because you are not eating." They are quick and easy and can help people who may be driving hours at a time -- like truck-drivers -- in the short-term, but the results don't last. Liquid calories don't suppress the appetite the same as solid food calories. Studies show people who drink 500 calories will eat more afterwards than people who eat 500 calories.
LOW-CARB FOODS: Perhaps the most popular diet trend of the last decade is the low-carb craze. This approach can work with some modifications to the strict "no-carb" approach. Dr. Kulze says the likely reason people lose weight on low-carb diets is because they're getting so much more protein -- remember, protein is nature's diet pill. But just because something is labeled low-carb doesn't mean it's good for you. Some foods labeled low-carb (like creamy sauces) actually contain more fat and more calories per serving than the same product that doesn't have the "low-carb" label. Instead of going low- or no-carb, go "right carb" and include fruits whole grains and beans, which are vital to health and metabolism. And for long-term diet success, remember: there are only three macronutrients -- protein, fat and carbohydrates. Dr. Kulze says, "You can't expect long-term success with body weight by just restricting one of the macronutrients. It really does take the right carbs, the right fats and the right proteins. That's the best way to lose weight."