Part II

Little Things Mean a Lot

People don't become overweight overnight.

Rather, the pounds creep up slowly, often unnoticed, until one day nothing in the closet fits

the way it used to.

Even more important than it's effect on looks and wardrobe, this gradual weight gain harms health.

At least six prior studies have found that rising weight increases the risk in women of heart disease,

diabetes, stroke, and breast cancer, and the risk in men of heart disease, diabetes and colon cancer.

The beauty of the new study is it's ability to show, based on real-life experience, how small changes

in eating, exercise, and other habits can result in large changes in body weight over the years.

On average, study participants gained a pound a year, which added up to 20 pounds in 20 years.

Some gained much more, about four pounds a year, while few managed to stay the same or even lose weight.

Participants who were overweight at the study's start tended to gain the most weight, which seriously

raised their risk of obesity related diseases, Dr. Hu said. "People who are already overweight have to be particularly careful about what they eat," he said.

The foods that contributed to the greatest weight gain were not surprising. French fries led the list: and 

increased consumption of this food alone was linked to an average weight gain of 3.4 pounds in each four year period. Other important contributors were potato chips (1.7 pounds), sugar sweetened drinks 

(1pound), red meats and processed meats (0.95 and 0.93 pound, respectively), other forms of potatoes

(0.57 pound), sweets and desserts (0.41 pound), refined grains (0.39 pound), other fried foods

(0.32 pound), 100-percent fruit juice (0.31 pound), and butter (0.30 pound).

Also not too surprising were most of the foods that resulted in weight loss or no gain when consumed

in greater amounts during the study: fruits, vegetables, and whole grains. Compared to those who gained the most weight, participants's in the Nurses Health Study who lost weight consumed 3.1 servings of vegetables each day.

But contrary to what many people believe, an increased intake of dairy products, whether low-fat 

(milk) or full-fat (milk and cheese), had a neutral effect on weight.

And despite conventional advice to eat less fat, weight loss was greatest among people who ate more yogurt and nuts, including peanut butter, over each four year period.

Nuts are high in vegetable fat, and previously small studies have shown eating peanut butter can help people lose weight and keep it off, probably because it slows the return of hunger.

That yogurt, among all foods, was most strongly linked to weight loss was the study's most surprising dietary finding, the researchers said. Participants who ate more yogurt lost an average of 0.82 pound per year.

Yogurt contains healthful bacteria that in animal studies increase the production of intestinal hormones that enhance satiety and decrease hunger, Dr. Hu said. The bacteria may also raise the body's metabolic rate, making weight control easier.

But, consistent with the study's findings, metabolism takes a hit from refined carbohydrates-suagrs and starches stripped of their fiber, like white flour. When Dr. david Ludwig of Children's Hospital Boston

compared the effects of whole grains in both animals and people, he found that metabolism, which determines how many calories are used at rest, slowed with the consumption of refined grains but stayed the same after consumption of whole grains.

(stay tuned)