The study showed that individuals would get better results if they analyzed the kinds of calories they consume because the body processes calories differently based on what food is being eaten.
The study revealed the foods that contributed to the greatest weight gain were French fries, potato chips, sugar-sweetened drinks and red meat.
The foods that resulted in the least amount of weight gain included fruits, vegetables and whole grains.
Nurses, doctors, dentists and veterinarians were all used in the study that was conducted for 12-20 years. Every two years, each individual was required to complete a questionnaire about eating habits and current weight.
The results from the questionnaire examined how a variety of factors influenced weight gain or loss during each four-year period of the study.
The results, which were published in the June issue of The New England Journal of Medicine, showed researchers the kinds of foods people ate had a larger effect on weight gain than how much food they ate.
"What you eat makes quite a difference. Just counting calories won't matter much unless you look at the kinds of calories you're eating," lead author of the study and cardiologist Dr. Dariush Mozaffarian told The New York Times.
Researchers claim individuals should put away the theory that they can eat any type of food while they diet, just as long as they eat it in moderation.
"The notion that it's OK to eat everything in moderation is just an excuse to eat whatever you want," said nutrition expert and co-author in the study, Dr. Frank B. Hu to the New York Times.
Hu continued, "People who are already overweight have to be particularly careful about what they eat."
According to the Center for Disease Control and Prevention, approximately 33.8% of American adults suffer from obesity. The CDC also states around 17% of individuals ages 2-19 are obese as well.
From the July 25, 2011, Prepared Foods' Daily News.