Modest weight loss can have lasting health benefits, research shows
Overweight and obese individuals can achieve a decade's worth of important health benefits by losing just 20 pounds, even if they regain the weight later that decade, according to research presented at the American Psychological Association's 120th Annual Convention. With a focus on psychology's role in overcoming the national obesity epidemic, the session also examined research that indicates foods high in sugar and fat could have addictive properties.
Rena Wing, PhD, professor of psychiatry and human behavior at Brown University's Alpert Medical School and director of the Weight Control and Diabetes Research Center at The Miriam Hospital in Providence, R.I., presented the latest in behavioral treatments for obesity in an address. Kelly Brownell, PhD, director of Yale University's Rudd Center for Food Policy and Obesity, cited some of the latest findings about food addiction in his talk. Brownell and Wing were keynote speakers for the convention's opening session.
"Obesity is the No. 1 health challenge facing our country today," APA President Suzanne Bennett Johnson said in introducing Wing and Brownell. "These psychologists have each contributed greatly in combating the obesity epidemic in different ways, one on the individual patient level and the other on the public policy level."
Johnson presented APA Awards for Outstanding Lifetime Contribution to Psychology to Wing and Brownell for their pioneering work in obesity research.
Wing referred to her work from the Diabetes Prevention Program, a national study of 3,000 overweight people with impaired glucose tolerance who were shown how to change their behavior rather than given drugs. It showed that even modest weight loss, an average of 14 pounds, reduced people's risk of developing Type 2 diabetes by 58 percent, she said. What's more, the health benefits of this weight loss lasted up to 10 years, even if people gained the weight back over this time, she said. Participants in the program practiced basic behavioral strategies to help them lose weight, including tracking everything they ate and reducing the amount of unhealthy foods they kept in their home, she said. They also met with coaches frequently and increased their physical activity over the course of the study.
"Helping people find ways to change their eating and activity behaviors and developing interventions other than medication to reinforce a healthy lifestyle have made a huge difference in preventing one of the major health problems in this country," Wing said in an interview. "Weight losses of just 10 percent of a person's body weight (or about 20 pounds in those who weigh 200 pounds) have also been shown to have a long-term impact on sleep apnea, hypertension and quality of life, and to slow the decline in mobility that occurs as people age."
Wing is leading a 13-year trial of 5,000 people with Type 2 diabetes. This study is testing whether an intensive behavioral intervention can decrease the risk of heart disease and heart attacks. "We are trying to show that behavior changes not only make people healthier in terms of reducing heart disease risk factors but actually can make them live longer," she said.
Changing food policy is another prevention approach where behavioral science is addressing the U.S. obesity epidemic, according to Brownell. "We need to be courageous in establishing policies that address obesity and we need to use science to better inform public policy," he said in an interview.
Brownell focused on the addictive impact of food. "The primary question is whether foods, particularly those high in sugar, act on the brain in ways that create signs of addiction," Brownell said. "Craving and withdrawal signs can be seen in animal and human brain imaging studies conducted by investigators around the world. This could fundamentally change the debate about diet, nutrition and obesity in this country."
If foods have addictive properties, policymakers might be spurred to create laws that would set limits on certain nutrients in food and curtail advertising of these types of foods to children, he said.