Body image affects weight gain in teen girls, University of Minnesota study finds

Self-perception among overweight girls can affect their weight gain over time, according to a new University of Minnesota study — but not necessarily in the way some scientists thought.

While one school of thought surmised that overweight girls with positive body images would gain more weight — feeling less motivated to adopt healthy habits — university researchers found the exact opposite.

"Some people believe if young people feel bad about their bodies, this might provide them … the necessary motivation to engage in weight-loss efforts," said Katie Loth, a study author and assistant professor at the U. "The results of this study suggest otherwise."

The finding is the latest to emerge from the U's Project EAT, an influential research program that has tracked 2,500 Twin Cities adolescents and teens on their attitudes about eating, physical activity and weight for nearly two decades. Previous Project EAT studies have validated the importance of family dinners, the influence of glamour images in the media and other factors that shape perspectives on what it means to be healthy.

In the latest study, the researchers found that overweight girls with negative body images, on average, gained three more points to their body mass indexes over a 10-year period. That may be because they try riskier diets and less successful weight-loss fads, Loth said.

The new study adds significantly to researchers' understanding of teen attitudes, she said, in that it shows that parents are wrong if they think shame will motivate their children to eat better and exercise. It also shows that adolescent attitudes about weight and body image can have long-lasting effects.

"It's often talked about as something they will grow out of and that won't impact young adulthood," she said. "This study shows that the way people feel about themselves in adolescence, and the behaviors they engage in during adolescence, really do seem to last."

The study, published in the latest edition of the Journal of Adolescent Health, focused on nearly 500 of the teens who were in the 85th percentile for body weight when they first started in Project EAT in 1998 and 1999. An earlier study checked on these participants after five years, when many were in college. Now the study assessed them as they started to approach their thirties and have children of their own.

Body image as a teen had an impact only on overweight females.

Those with a positive image recorded, on average, a 2.9-point increase in BMI, or body mass index, a decade later. (BMI is derived by dividing weight in kilograms by height in meters.)

But those with a negative body image recorded a 6.4-point increase in BMI for females in the study.

Males in the study apparently weren't swayed by their personal body images in the type and frequency of their fitness activities, the study found.

The findings match realities for pediatricians and youth workers. Even though the findings were based on teens from the '90s, the same idealism of the perfect body exists today. Only now, the pressure can come out in the edited pictures that teens post on social media to get attention, said Evan Barnett, a youth development specialist with the Minneapolis Youth Coordinating Board. "All they have to do is get the right Photoshopped image on Instagram so they can get their 25 likes."

Dr. Nimi Singh tries one-on-one interviews with adolescents at the Fairview Children's Clinic in Minneapolis to discuss how they feel about their body images and their strengths and weaknesses when it comes to adopting long-term healthy habits and seeing themselves positively.

She tries to avoid having parents express concerns about weight in front of their children, which can unwittingly perpetuate that sense of shame.

"If a young person is struggling with a negative self-concept, and they don't learn the skills to rewrite that story, then that can lead to low moods and unhealthy coping strategies," said the adolescent health specialist. "And those coping strategies can be overeating, but they can be many other things. Young people who feel badly about themselves will do anything to shut off that negative story."

Loth said she was pleased that the study debunked the notion that negative reinforcement triggers healthy behaviors.

Parents and teachers should discourage teasing or unhealthy talk about weight, and encourage a focus on fitness and feeling healthy rather than weight and image, she said.

"The messages we put out for people need to be focused on healthy behaviors and not on shaming people for the weights that they are at."

Jeremy Olson • 612-673-7744