Poor Body-Size Judgment Can Lead to Increased Tolerance of Obesity

Seven in every 10 obese adults underestimate how much someone weighs, researchers at Columbia University Medical Center have found, while people of normal weight make this mistake much less often. Mothers of overweight or obese children also tend to misjudge their children’s size, as youngsters misjudge their obese mothers’ size, says lead author Tracy Paul, MD, a 2011 graduate of Columbia University College of Physicians & Surgeons, in a study published online by the Journal of General Internal Medicine. Dr. Paul, who is now a cardiology fellow at Weill-Cornell Medical College, conducted the research during her years as a medical student at Columbia and her internal medicine residency at NewYork-Presbyterian Hospital/Columbia.

If abnormal weight among children is not addressed in a timely way, it can set in motion lifelong distorted perceptions of what is acceptable and healthy and contribute to adolescent and adult obesity, say the authors. However, prevention efforts are often challenging because many parents of obese children do not try to prevent their children from becoming obese. The research team tested the assumption that this happens because parents often do not perceive weight as a problem or do not see the link between obesity and health problems. The researchers queried 253 mothers and their children at an outpatient pediatric dental clinic at Columbia about their perceptions of what healthy and ideal body sizes are. Most participants were Hispanic (82.2 percent).

The researchers found that 71.4 percent of obese adults and 35.1 percent of overweight adults underestimated size, compared with 8.6 percent of people of normal weight. Among overweight and obese children, 86.3 percent and 62.3 percent, respectively, thought they weighed less than they did, vs. 14.9 percent of children of normal weight. Eighty percent of mothers of overweight children underestimated their child’s weight compared with 7.1 percent of mothers of children of normal weight and 23.1 percent of mothers with obese offspring. Children with obese mothers, too, found weight difficult to judge, with the vast majority of them incorrectly classifying an adult’s size.

People who design and implement programs aimed at reversing obesity trends should note that family members often struggle to make an accurate call on weight matters, says Dr. Paul. She underscores the importance of recognizing high-risk and understudied subgroups because age, ethnicity, and socioeconomic status all influence childhood obesity.

“The failure to recognize abnormal weight occurs more often among overweight or obese mothers and children. Children of obese mothers often also underestimate adult size, suggesting that tolerance of being overweight is common among children exposed to obese parents,” says Dr. Paul. “This is worrying, as flawed weight perception impedes one’s ability to recognize obesity and its risks as a personal health issue.”

The study was published in the September 2014 issue of the Journal of General Internal Medicine, the official journal of the Society of General Internal Medicine. Other authors of the paper, all from the Center for Women’s Health in the Department of Medicine’s cardiology division, are Robert R. Sciacca, EngScD; Michael Bier; Juviza Rodriguez; Sharon Song; and Elsa-Grace V. Giardina, MD.


This article is based on a press release prepared by the Society of General Internal Medicine.