Growth factors abound
Chewing gum, taking medication and laying off fast food won’t by themselves reduce America’s waistlines -- obviously. But they may all have a part to play.
As hundreds of medical, scientific and behavioral researchers gathered at the Obesity Society’s annual meeting in New Orleans last week to present their work, they increased the collective understanding of how appetite, metabolism, the environment and our genes may contribute to the nation’s increasing girth.
The smorgasbord of issues illustrates the many-pronged approach health experts are taking in the fight against ever-expanding waistlines, says Eric Ravussin, outgoing president of the Silver Spring, Md.-based organization, which promotes research and education on obesity. Researchers realize that numerous factors are to blame for Americans’ stubborn inability to shed their collective weight. “It goes from genetics to behavior,” he says. “There’s a whole session on gastrointestinal signals to the brain. [Researchers are] really trying to put these things together.”
--
Dine out and pay the price
One vital element is where and how often Americans are eating out. A study by researchers at Temple University in Philadelphia reported that Americans were less likely in 2006 than in 2004 to pay more for healthful foods (40.7% versus 28.5%), knew less about healthful menu items (18.5% versus 12.4%) and were more likely to regard healthful foods as bland (21.4% versus 15.8%).
Gary Foster, the Obesity Society’s new president and a coauthor of the study, doesn’t blame them for their reluctance to part with more money. (Data on 12,000 Americans nationwide was collected by Aramark, a food service and facility management company based in Philadelphia, which did not fund the study.)
“I don’t think that’s an unreasonable position for consumers to be in,” says Foster, director of the Center for Obesity Research and Education at Temple University. “Why pay more for healthy foods? In the end, taste and cost trump everything else, and convenience is in there, too.”
Although there is a segment of the population that doesn’t mind paying extra for fruits, vegetables and more healthful offerings in restaurants, he says, most won’t bust their budget for them.
“The challenge,” adds Foster, “is to make the foods tasty and affordable. This is not about finger-pointing. But it does signal that you have to be in the ballpark in terms of taste, convenience and cost, or people won’t be willing to do it.”
Americans know they should eat at home more but radical changes in their behavior are unlikely, he says. “People are going to continue to eat out,” he says. “The call should be to get people to eat healthier when they’re out. Why make it tougher?”
--
Married couples grow together
Another study found that the early years of marriage can be a catalyst for weight gain. Of 1,200 people 18 to 28 in relationships, married couples’ average weight gain was 6 to 9 pounds more than that of their single, dating peers.
“This is an understudied period,” says Penny Gordon-Larsen, assistant professor of nutrition in the school of public health at the University of North Carolina at Chapel Hill and author of the study. Having studied environmental influences on obesity, she wondered if living together or just being in a romantic relationship was the important component of the weight gain. “The shared household environment seemed to be the key.” Eating out more often and leading a busy lifestyle filled with work and social obligations, she theorizes, might contribute to the problem.
“If the couples support each other in having a healthier house and healthy activities,” Larsen says, “there might be hope for reducing that weight gain.”
Behaviorial changes alone are unlikely to help everyone lose weight, however. For those whose pounds stubbornly remain, studies on two new weight-loss drugs offer some hope. The compounds, still in clinical trials, have shown promise in helping people lose weight and sustain that weight loss for a year.
Both are from San Diego-based pharmaceutical company Orexigen and are combinations of already available medications. Contrave (in phase III trials) uses the antidepressant bupropion (brand name, Wellbutrin), which can suppress appetite and increase calorie burn. It also contains naltrexone, which is usually used to treat addiction to alcohol and opiods but can also affect appetite and rev up the metabolism.
The second drug, Empatic (in phase II trials), also uses bupropion, but in conjunction with zonisamide, an anti-seizure medication that has been shown in other studies to be effective for weight loss.
In Contrave trials, different formulations of the drug resulted in a mean weight loss ranging from 7.1% to 7.6%, compared with 1.1% for a placebo after 24 weeks. The highest dose group in Empatic trials showed a 10.3% weight loss, compared with 1.2% for the placebo group after 24 weeks. Approximately 3,000 men and women have taken part in the randomized, placebo-controlled studies.
“With conventional weight-loss approaches using diet or drugs, you see a common problem of a weight-loss plateau,” says Dr. Gary Tollefson, Orexigen’s president and chief executive and coauthor of some of the studies. “After about 12 to 18 weeks, people stop losing weight, and that causes them to get frustrated.”
These new drugs, he adds, target the neural pathways responsible for cravings and appetite surges. “For some people there is an addictive-like component to some foods. I think these medications . . . can help control some of those impulses in the brain. It’s a tool -- there are no pharmaceutical cures for the problem, but this can help.”
--
Gum may dull hunger
Something less drastic -- chewing gum -- might also help curb appetites between meals, according to a study out of Scotland that had 60 people (almost all women) chewing gum (mostly sugar-free) at various intervals after eating lunch (the participants also served as their own control group). About three hours after the meal, the subjects were offered salty and sweet snacks. Chewing gym reduced calorie intake by about 25 calories on average. The study was funded by the Wrigley Science Institute.
“Clearly, chewing is very satisfying,” enough to take a slight edge off an appetite, says Marion Hetherington, professor of biopsychology at Glasgow Caledonian University in Glasgow. Although the gum added no calorie punch, “you’re getting the pleasure of the intense flavors,” which may act as an hunger suppressant. “It’s a useful tool and one of many.”
--
--
(BEGIN TEXT OF INFOBOX)
New studies on why we gain and how we lose
Here are other studies presented at the obesity conference:
* Women who had misperceptions about their weight before pregnancy were more likely to gain excess weight during pregnancy than women who had accurately estimated their weight, according to a study out of Harvard Medical School. The study included 1,536 normal weight and overweight women who were asked to estimate their weight; those who over- or underestimated their weight were more likely to gain excess weight during pregnancy, with overweight women who had underestimated their weight gaining the most.
* At least one community-based program can help lower body mass index in children -- but not very much. In this study from the Friedman School of Nutrition Science and Policy at Tufts University, three culturally diverse cities in Massachusetts were involved; one, Somerville, served as the intervention, two as the control. About 300 kids in Somerville had access to physical activity programs and healthful foods for two years. Very little difference was shown in BMI scores among the three groups.
* Functional MRI studies reveal differences in brain activity among nine restrained eaters and 10 unrestrained eaters while looking at pictures of both highly and moderately palatable foods after both fasting and eating. Researchers at the University of Rochester Medical Center found that while viewing pictures of highly palatable foods after fasting, unrestrained eaters showed bilateral brain activity in areas associated with hunger, memory and motivation. Restrained eaters showed activity just in the right cerebellum, which is involved with low-level processing of appetite stimuli. Differing brain patterns could suggest restrained eaters are less hungry after fasting than unrestrained ones.
* “Super losers,” people who are able to lose a significant amount of weight (in this instance, 23% among 29 men and women), share some behavioral traits, according to a study from Duke University. They do cardiovascular exercise four to six times a week; avoid risky food situations; eat three meals a day, often repeating foods; track their weight and diet; want to lose more weight; enjoy their improved appearance and health; and maintain a positive attitude despite worrying about how to sustain their motivation and handle stress.
* The transition from adolescence to young adulthood is a risky one when it comes to gaining weight. Researchers from the University of North Carolina at Chapel Hill analyzed data from about 14,000 participants in the National Longitudinal Study of Adolescent Health in two periods: one when participants were aged 12 to 22, another when they were aged 18 to 28. Between the two test periods, heavy fast-food consumption increased from 36% to 41%, moderate and vigorous physical activity dropped from 32% to 13% and high screen time went from 52% to 58%. Obesity rates almost doubled, from 12% to 22%.
-- Jeannine Stein
