"Many of these weight loss myths are completely harmless, although they're often ineffective, not to mention inconvenient," says Molly Kimball, MS, RD, a nutritionist at the Ochsner Clinic Foundation in New Orleans. "Other myths may pose danger, such as strict fasts or semi-starvation diets. As a general rule, when evaluating a promise or claim, keep in mind that if it seems too good to be true, it probably is."
But what about the "tried and true" methods of losing weight, such as eating grapefruit, spicy foods or lots of fiber? Do these so-called miracle foods really work?
FAT BURNING FOODS: There's one food that comes to mind when I think of "fat burning" and that's grapefruit. The Grapefruit Diet claims that the acid in the fruit helps the body burn fat. Sorry to disappoint you, but it's just not so. Any weight loss on this diet would be due to decreased caloric intake. "This myth is as old as the orchard hills. Grapefruits don't burn fat. If they did, Floridians would be as fit as a fiddle. There isn't any food that burns body fat," says Joan Salge Blake, MS, RD, LDN, a Nutrition Professor at Boston University.
FIBER: Yes, fiber really does help you lose weight. Fiber is the indigestible portion of plant foods. Water-soluble fiber helps people lose weight in two ways. First, it provides bulk, which makes you feel full. Additionally, fiber slows digestion, which makes you feel satisfied longer. "If you've ever put oat bran in water or milk, you will see that it absorbs the liquid and expands in volume. Since we lack the enzymes to digest fiber, we can't absorb it — so it gives us a full feeling," says Shari Lieberman, PhD, Professor at the University of Bridgeport, School of Human Nutrition and author of Dare To Lose (Avery/Penguin Putnam, 2002).
KEEP IT SPICY: If you've heard that spicy food raises your metabolism and will help you drop pounds faster — sorry again! Spicy foods may boost your metabolism slightly, but unfortunately, it's too small to be significant. Even so, spicy foods can help in other ways. "By eating spicier, tastier foods, it may help us feel satisfied sooner from a sensory standpoint, giving us more of an eating experience," says Melanie R. Polk, MMSc, RD, FADA, Director of Nutrition Education of the American Institute for Cancer Research.
ICE COLD WATER: Your body temperature is incredibly hot at approximately 98.6 degrees Fahrenheit and ice water is about 40 degrees Fahrenheit. So in order to maintain homeostasis, your body has to bring that ice water temperature up by about 60 degrees Fahrenheit — does your body burn calories in the process?
By definition, it takes 1 calorie to raise the temperature of 1 liter of water by approximately 2 degrees Fahrenheit. That means that to raise the temperature of 1 liter of ice water by 60 degrees Fahrenheit, to normal body temperature, your body would burn about 30 calories. 2 liters would burn 60 calories — which is about 8 glasses of water per day. "Believe it or not, this is actually true — your body needs to warm up cold liquids because it needs to maintain a constant internal temperature," says Jay T. Kearney, PhD, former Director of the Sports Science and Technology Division at the U.S. Olympic Training Center, and Vice President of HealtheTech. "Therefore calories are burned to warm liquid up to your body temperature."
An additional benefit of drinking water — it makes you feel full.
A CUP OF JAVA: Can caffeine help you lose weight? I assumed it would — it's a natural stimulant, and it seems that if your body is stimulated it will burn more calories. Unfortunately it doesn't work that way. Although it may have a very minor role in increasing metabolic rates in first-time caffeine users, "with chronic caffeine consumption most of these effects become muted — the individual develops tolerance to most of [the effects]," says Herbert Muncie, MD, Chairman of the Department of Family Medicine at the University of Maryland.