Newswise — In today's low-carb craze, weight loss plans that once promoted low-fat, high-carbohydrate foods like potatoes and breads as the keys to a healthy diet have been pushed aside in favor of a menu of meats, eggs, and cheeses. Even the Burger King Whopper has gone bunless.

But are carbohydrates really the culprit behind America's troubling obesity epidemic? University of Michigan Health System registered dietitian Cathy Fitzgerald weighs in with the truth about these low-carbohydrate diets and how to achieve healthy and lasting weight loss.

According to Fitzgerald, the low-carb craze — which brought us weight-loss plans like the Atkins diet, The South Beach diet, The Zone, and Sugar Busters — is not the cure-all for America's weight problem. "As Americans, we're always looking for an easy answer to solve our weight problems," she says. But stop and think: common sense tells you that cutting out all carbs and turning to supposedly "healthy" deep fried chicken and low-carb beer is not the path towards a healthier lifestyle.

"These foods are not healthy for you," she stresses. Fitzgerald also recommends adhering to the old adage: "if it sounds too good to be true, it probably is. "

What do carbohydrates do?The recent boom of low-carbohydrate and even carbohydrate-free diets and foods has left many wondering if carbohydrates are necessary at all? The answer is a resounding yes, according to Fitzgerald.

"We need them because they are our primary source of energy," she explains. "They are the fuel that makes us go and keep the processes in our bodies going."

Of course, reducing some less-healthy carbohydrates, like added sugars from multiple cans of soda pop a day, can be a healthy choice for your body. "But there are too many things that carbohydrates bring to our bodies that we really need to have, like certain vitamins and minerals that we only get from carbohydrates," Fitzgerald explains.

But don't carbohydrates cause weight gain?Fitzgerald stresses that it's not the carbs. It's the calories. You can overeat carbohydrates, just like you can overeat protein or fat. And too much of any of them will cause weight gain. "When we take in more calories than what the body needs in a day, we're going to store that excess as added weight. A balanced diet requires that your food intake matches what your body uses energy-wise," she says.

Increased portion sizes are closely related to obesity. Not only have fast-food joints super-sized our burgers, fries, and soft drinks, but also our eating habits at home have changed. "Our plates have gotten bigger and we just put more food on them," Fitzgerald says. More food coupled with less physical activity can only result in one thing: gaining weight. So, why do low-carb diets cause weight loss?

Carbohydrate-reduced or carbohydrate-free diets appear to work on the surface. Rapid weight loss during the first week as you stop eating carbohydrates is attributed mostly to the loss of water weight. When you stop eating carbohydrates, your body searches for other sources of energy. It locates carbohydrates that it has previously stored as glycogen for energy. When glycogen is used as energy, water is released and leaves the body, resulting in weight loss. Another "secret" behind carbohydrate-reduced diets is that people generally don't lose weight because they are eating low-carbohydrate, high-protein foods — but rather because they are taking in fewer calories day after day than what their bodies use up. Fitzgerald also notes that eating the same kind of high-protein foods for days becomes boring, so dieters eat less overall.

And despite impressive short-term results, low-carb dieters have low success rates in the long term. When individuals stop dieting and return to their former eating habits, they gain the weight back. "That's why making healthy lifestyle changes, something you can live with forever, is a lot better idea than a fad diet," recommends Fitzgerald. Low-carb diet downfalls

Low-carb dieters should beware of the potential dangers of low-carb or reduced-carbohydrate diets. According to Fitzgerald, low-carb dieters may not get enough fiber, which keeps us regular and reduces the risk for heart disease, some cancers, and diabetes. Without eating carbohydrates from plant sources like fruits, vegetables, whole grains, and beans — foods limited or banned on low-carbohydrate diet plans — we cannot get enough fiber into our diets to meet today's increased fiber recommendations. As sources of complex carbohydrates, these foods take longer to be digested than simple carbohydrates like sugars, leaving you feeling full longer. Research is also now underway to examine whether the total fat, saturated fat, and cholesterol that low-carb dieters ingest at excessive levels can lead to potentially-deadly diseases like heart disease and an array of cancers. Low-cab dieters should also be aware that low-carbohydrate and low-calorie are not the same thing, just as low-fat and low-calorie are not the same thing. When something, like carbohydrates, is taken out of a product, like chips, ice-cream, or chocolate bars, other things are added in to replace what has been taken out. But many dieters look no further than the front of the product, neglecting the nutrition facts label, before making food choices, a crucial diet mistake. "Sometimes the calories may have even increased, even if the carbohydrates have decreased," Fitzgerald says. Low-carbohydrate foods also seduce and mislead hungry dieters. "We think we're fine, as long as we choose low-carb products. But it all boils down to how much of it we eat," she cautions. New low-carbohydrate products are also probably going to cost more than the original. "Maybe it's a better idea to reduce your portion size of that regular carbohydrate that you would have bought, but enjoy it in moderation" she suggests. Making better choices

When looking to lose weight, people should turn to complex, unrefined carbohydrates, full of fiber and nutrients. Eating a slice of whole grain bread, rather than a couple of crackers made from processed flour with a lower-fiber content, is a better diet choice because foods made from white flour like white bread, white rice, and pasta lose much of their nutrient value as they are processed. Fitzgerald also recommends replacing refined sugary cereals with whole grain cereal.

Snack foods, like chips, and sweets, like cakes, cookies and pie, made from processed flours are also a place to limit carbohydrates because they also have added fat. These foods contain a lot of calories and we tend to eat large amounts because they taste good. "It's really a double trap for us." Fitzgerald warns.

Dietitians also advise choosing lean meats, poultry, and fish, low-fat dairy products, and drinking water every day. Avoid saturated and trans fats found in processed foods like crackers, bakery foods and fried foods, and processed and fatty meats. Getting physical

Physical activity not only makes you healthier, but also burns calories. Physical activity has been shown to be an important component of weight management. Increased physical activity can simply mean adding daily walking to your routine for just five, ten, or fifteen minutes a day. Regular physical activity may also benefit your mood, lower your pulse, blood pressure, cholesterol, and blood sugar, and increase your energy level. "Plus, it's just so much fun to do," says Fitzgerald. "Once you get into it, you'll miss it if you don't do it." Healthy weight loss

The bottom line is that to lose weight you must take in fewer calories than your body uses in a day. If you take in just 100 calories less a day, over the course of one year you're going to see dramatic results. Healthy weight loss is considered one to two pounds per week. "After all, you didn't gain the weight overnight, why should you expect to lose it overnight?" she says.

People who have committed themselves to losing weight and are ready to make a change need to evaluate their lifestyles. Can you take some snack foods out of your diet? Can you eat a piece of fruit instead of a bag of chips or enjoy one can of pop rather than having two in a day? By starting small and making changes that you can live with, you will be successful at weight loss and keep the weight off in the long-term. "Unfortunately, there is no silver bullet to losing weight," says Fitzgerald. "Just go back to healthy eating and eat a little less."

For more information, visit the following Web sites:

UMHS Health Topics A-Z: Obesity and diet

UMHS Health Topics A-Z: Healthy diet

MEDLINEplus Health Information - Carbohydrates

Dietary Guidelines for Americans

American Heart Association: Diet and Nutrition

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