November 23, 2004, Tuesday


LAS VEGAS - Obesity researchers from around the world went home last weekend with some new data to chew on.

Several studies, released last week at the annual meeting of the North American Association for the Study of Obesity, offered practical suggestions on how to lose weight and keep it off.

One researcher found that adding fiber-rich vegetables to pizza, pasta and other dishes and cutting back on portions a little can help dieters trim up to 800 calories a day without even noticing.

This means, for example, adding foods such as tomatoes, green peppers and onions to pizza, and baking with applesauce instead of oil.

Nutrition professor Barbara Rolls and colleagues at Pennsylvania State University had 24 young women eat all their meals at the university laboratory two days a week for four weeks. The same foods were served, but some were prepared differently so that they weren't quite as laden with calories.

Other research has shown that over the course of a day or two, a person eats the same weight of food each day. So experts believe that increasing the fruits and vegetables in dishes so they are higher in fiber and water will help people lower their calories without feeling deprived.


  • Participants consumed 544 calories a day less by eating the produce-rich recipes instead of the high-calorie ones. They cut 256 calories a day by trimming portions by 25%.
  • Those who ate the lower-calorie, slightly smaller dishes were not any hungrier than those who ate the other dishes.
  • Emphasizes that the only proven way to lose weight is to eat fewer calories than your body uses as fuel for your activities.
  • Dieters liked the taste of the lower-calorie dishes just as much as the others.
  • "Whenever you talk to people about how they successfully manage their weight, this is how they do it," says Rolls, author of The Volumetrics Weight-Control Plan.

    "They don't worry about everything they're eating. They have found foods they enjoy that keep them full and satisfied," Rolls says. "Food companies need to make it easier for people to eat like this."

    Another study looked at how to keep many Americans from continuing to gain a pound or more a year.

    To figure out what exercise prescriptions will help, University of Pittsburgh researchers followed 114 overweight men and women who exercised regularly for 12 months.

    Participants were divided into three groups: a moderate-exercise group that worked out 20 to 30 minutes five days a week; a high-dose exercise group that worked out 20 to 60 minutes five days a week; and an information-only group that had an initial session of exercise instruction and received a book and monthly newsletter on how to increase physical activity.

    All three groups were told to eat healthfully without cutting calories.

    Most people in the first two groups took walks on their own for four days a week, went into an exercise facility at least once a week, and used a treadmill or other equipment.

    On average, people in all three groups lost a modest amount of weight. And the more people exercised, the greater improvements they made in their cardiovascular fitness. That is, it became easier for them to do things such as climbing up steps or walking longer distances.

    "Considering that the average American adult gains a few pounds a year, these findings are encouraging and provide a first step in preventing weight gain that may lead to obesity," says lead author John Jakicic, director of the Physical Activity and Weight Management Research Center at the University of Pittsburgh.

    "We need to help people make small lifestyle changes to prevent that weight gain," says James Hill, director of the Center for Human Nutrition at the University of Colorado Health Sciences Center and co-founder of America on the Move, which encourages people to take 2,000 more steps a day and eat 100 fewer calories.



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