Just because you're losing weight on a low-carb diet doesn't mean it's a healthy diet.
A study being published Tuesday in the Annals of Internal Medicine says a low-carb diet based on animal protein increases the risk for cancer and death.
However, a vegetable-based low-carb diet may contribute to lower heart disease and death rates, the research indicates.
CBS News Medical Correspondent Dr. Jennifer Ashton noted on "The Early Show" the study didn't look specifically at popular diets, such as the Atkins Diet. Instead, it generalized between animal-based and vegetable-based low-carb diets.
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The research, she explained, looked at about 130,000 people, and found that low-carb diets based on animal proteins were associated with a higher death rate compared to vegetable-based low carb diets. Meat-based low carb diets were specifically linked to higher lung and colorectal cancer deaths -- other studies have also confirmed that red-meats and processed meats carry cancer risks. Meat-based diets often are high in saturated fats and cholesterol.
A veggie protein-based low-carb diet, Ashton points out, includes healthy fats, such as olive oil and avocado, no-starch gluten products, soy foods, nuts, beans, fruits and vegetables.
The study found that a benefit of this type of diet is that it can have a lower risk for heart disease. Other studies have found that low-calorie, low-carb diets have improved BAD cholesterol levels and other heart disease risk factors. With a vegetable-based low-carb diet, you're consuming more unsaturated fats, dietary fiber and micronutrients, such as magnesium and potassium.
Ashton added that, while these diets are low-carb, that doesn't mean you completely eliminate carbohydrates. You need them, and there are healthy ones.
Americans consume unhealthy amounts of bad carbohydrates and starches, such as sugar, and products that contained white flour, such as bread. But the Institute of Medicine recommends that adults get 45-65 percent of their calories from carbohydrates to provide enough energy and fuel for physical activity and good health. These low-carb diets generally advise people to consume about half of that recommended amount.
Healthy carb substitutes include whole grains, such as high-fiber oat-bran cereal and brown rice, beans for protein and fiber, and fruits and vegetables, such as okra and eggplant. These boost your health by incorporating minerals, vitamins and fiber into your diet.
Another study out Tuesday finds that consumers often misinterpret low-carb claims on the front of food packages.
The study, in the Journal of Nutrition Education and Behavior, observed a 516 percent increase in sales of low-carb foods from 2001 to 2005.
What consumers and dieters need to know, says Ashton, is that you need to check out the claims from these products. Check the nutrition facts panel on the back of the package to see if the contents fit into the type of diet you're aiming for -- this packaged food is supposed to be part of an overall diet -- and just because it's low in carbs doesn't mean it's low in calories. A good rule of thumb is to always look for that Nutrition Facts panel on the package.
Ashton stressed that you should consult your doctor before starting any diet, especially if you have health issues. For example, people with a history of heart disease should probably avoid a low-carb diet that focuses on meats, because of its saturated fats.
You want to remember that to lose weight, you will probably have to decrease the number of calories you consume. These diets -- whether they're low-carb or low-fat -- usually reduce the numbers of calories you take in. You also want to look for diets that are flexible in a healthy way -- instead of completely restricting one type of food, look for a diet that incorporates a lot of food groups. That way, you'll be more likely to stick with it. since it gives you more choices.
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