Vast Majority Of Adults At Risk Of Becoming Overweight Or Obese

Researchers analyzed the short-termand long-term chances of developing overweight and obesity among morethan 4,000 white adults enrolled in the offspring cohort of NHLBI'slandmark Framingham Heart Study, an ongoing longitudinal study inFramingham, Massachusetts. Participants ages 30 to 59 were followed for30 years, from 1971 to 2001. The results appear in the October 4, 2005,issue of the Annals of Internal Medicine.

“National surveys andother studies have told us that the United States has a major weightproblem, but this study suggests that we could have an even moreserious degree of overweight and obesity over the next few decades,”said NHLBI Director Elizabeth G. Nabel, M.D., who also co-chairs theNIH Obesity Research Task Force. “In addition, these results mayunderestimate the risk for some ethnic groups.”

Framinghamparticipants were white, and other studies have shown, for example,that Hispanic and black individuals, especially women, have a greaterprevalence of excess weight compared to their white counterparts.

Accordingto the National Center for Health Statistics, part of the Centers forDisease Control and Prevention, 65 percent of U.S. adults aged 20 yearsand older are either overweight or obese, and approximately 30 percentof adults are obese. These estimates are from the 1999-2002 NationalHealth and Nutrition Examination Survey, a population-based survey.

Framinghamresearchers assessed the participants’ body mass index (BMI) – astandard measure of weight relative to height, which is an indicator oftotal body fat. A BMI of 18.5 to 24.9 kg/m2 is considered a normal, orhealthy, weight for adults. Overweight is a BMI of 25 to 29.9 kg/m2,and obesity is a BMI of 30 kg/m2 or higher.

Making it to middleage without extra pounds was no guarantee for staying at a healthyweight – even in the short term. About one in five women and one infour men who were at a healthy BMI at a routine Framingham studyexamination became overweight after four years. Among those who wereoverweight, 16 to 23 percent of women and 12 to 13 percent of menbecame obese within four years.

“Our results, although notsurprising, are worrisome,” comments Ramachandran Vasan, M.D.,Associate Professor of Medicine at Boston University School of Medicineand lead author of the study. “If the trend continues, our country willcontinue to face substantial health problems related to excess weight.”

“Overweightand obesity increase the risk of poor health. We hope these resultswill serve as a wake-up call to Americans of all ages,” adds Nabel.“Even those who are now at a healthy weight need to be careful aboutmaintaining energy balance to avoid gaining weight. Taking simple stepsto make sure that the overall the number of calories you consume do notexceed the amount you burn can play a major role in lowering your riskfor many chronic conditions.”

Overweight increases the likelihoodof developing diabetes, high blood pressure and heart disease, stroke,breathing problems such as asthma and sleep apnea, some cancers,osteoarthritis, and gall bladder disease. Obesity is associated withthese conditions as well as with early death. Research has shown thateven a small weight loss (just 10 percent of body weight) can helppeople who are overweight or obese lower their risk of developing manyof these conditions.

The Clinical Guidelines on theIdentification, Evaluation, and Treatment of Overweight and Obesity inAdults recommend that both people who are overweight as well as thosewho are at a healthy weight prevent weight gain. The guidelines areavailable online at http://www.nhlbi.nih.gov/guidelines/obesity/ob_home.htm.

Strategiesthat promote a healthy weight beginning in childhood are critical. Forinformation on We Can!, NIH’s national education program to enhancechildren’s activity and nutrition to prevent childhood obesity, visitthe website at http://wecan.nhlbi.nih.gov or call toll-free 866-35-WECAN.

For help assessing obesity risk and advice on how to lose weight, consult your healthcare professional.

Resources:

* Body Mass Index Calculator: http://www.nhlbisupport.com/bmi/bmicalc.htm.
* Aim for a Healthy Weight: http://www.nhlbi.nih.gov/health/public/heart/obesity/lose_wt/patmats.htm
* Portion Distortion: http://hin.nhlbi.nih.gov/portion
* We Can! Families Finding the Balance – A Parent Handbook (in English or Spanish): http://www.nhlbi.nih.gov/health/public/heart/obesity/wecan_mats/parent_hb_en.htm
* Dietary Guidelines for Americans 2005: http://www.usda.gov/cnpp/dietary_guidelines.html