Obesity is a worldwide problem and is getting worse. Losing weight is difficult for most people. A study in the New England Journal of Medicine reports fewer than 25 percent of Americans who try diets actually lose weight and a majority who do lose weight have difficulty maintaining the loss. Billions of dollars are spent on weight loss programs. VOA's Melinda Smith has more on recent findings that may put to rest the argument about which diet works the best.

The World Health Organization estimates there are more than one billion adults who are overweight, and 400 million others considered obese.  

Another 20 million children under the age of five are overweight. So why can't we lose weight?

Fad diets often run their course and disappear from popularity as people lose, then regain. But three diets seem to be the most generally accepted: The low fat diet promotes whole grains, fruit and vegetables.  

A diet low in carbohydrates is based primarily on protein such as eggs, red meat, chicken and fish and some vegetables.

And lastly -- [is] a diet based on the Mediterranean style of cooking. That includes smaller portions of meat and fish, and larger portions of fruit, vegetables, grains, along with nuts, seeds as well as olive oil.

In the studies published recently, several hundred overweight and obese patients were asked to follow one of these three diets. After a period of two years, patients on the low carb diet lost the most.

Dr. Eric Westman

"It's not surprising that the low carbohydrate diet led to greater weight loss, because when you're eating protein and fat it makes you feel full so you don't want to eat as much,"
Dr. Eric Westman said. He is one of the researchers with the Duke University Medical School.
Being overweight or obese often leads to serious health problems.  

Fat laden foods lead to high cholesterol and insulin levels, which often lead to heart disease, stroke and diabetes. Researchers found the diet low in carbohydrates helped to lower those levels.

"A low carb diet -- one that foregoes rice and pasta and bread and potatoes -- works by lowering insulin levels in the body," Dr. Westman said. "And then with this lower insulin level, the body makes less of harmful cholesterol."

In previous clinical trials, it has been difficult to measure the effectiveness of weight loss diets over the long term. These recent studies in Israel and the United States have been the longest controlled trials to date.