‘Throw away the scale’ to improve mental health: study

TORONTO – When you hear the words ‘successful exercise program,’ you may be inclined to think of scales, measuring tape and the seemingly unreachable goal of wearing a smaller size of pants.

But a new study suggests that even light to moderate exercise that yields no weight loss or change in body fat has a positive mental health effect on overweight and obese teens.

The lead researcher is Dr. Gary Goldfield, a registered psychologist, clinical researcher at the Children’s Hospital of Eastern Ontario (CHEO) Research Institute, and associate professor in the Department of Pediatrics at the University of Ottawa. Goldfield has conducted many treatment studies for overweight teens, including nutrition and web-based interventions.

In this study, Goldfield wanted to know how exercise impacts psychosocial factors like body dissatisfaction, social alienation and low self-esteem in overweight teens, since these teens are often at higher risk for these factors. He says previous research tended to show that people who lost the most weight in exercise interventions reaped the greatest psychosocial benefits.

“But this didn’t show that,” Goldfield said. “It showed that psychosocial benefits can be derived from exercise in the absence of weight loss or changes in body composition – BMI.”

The study, published Monday in the Journal of Pediatric Psychology, looked at 26 overweight and obese teens, most of whom were obese. The teens visited the CHEO lab twice a week for ten weeks, where they completed 60 minute sessions of cycling. The teens cycled on a stationary PlayStation 2 GameBike, and could pedal at any intensity they wanted, taking breaks and stopping whenever they chose.

One group cycled with the GameBike video game console turned on (and played the game), while the other group had the console off and listened to music of their choosing. They cycled independently from other participants, but with an exercise physiologist present to monitor their activity.

The participants had their height, BMI and body composition measured. They also completed a body image survey and a self-perception profile for adolescents.

Results

Physiologically speaking, the results were not dramatic: an increase in aerobic fitness, along with small but statistically significant reductions in body fat and cholesterol after the ten weeks; with no differences between the two groups.

But, there were measurable improvements in psychosocial functioning, “particularly body image, perceived social competence, and perceived academic performance,” says Goldfield.

While there was no improvement shown in terms of self-esteem, Goldfield says improved body image is important for a number of reasons.

The improvement in perceived academic performance was not verified by report cards or teacher interviews, but prior research has shown that activity does promote better thinking, cognition and memory, according to Goldfield.

Limitations

As with any study, the CHEO research has limitations. It was lab-based so may not generalize to the ‘real world,’ there was no follow up to see if the positive mental health boost lasted beyond the study, and the exercise physiologist working with participants may have played a part in the improved social confidence.

In addition, there could be what Goldfield calls ‘social desirability responding’ which refers to how these teens became comfortable in the lab, were paid $10 per visit for their time, and thus wanted to give the answers they thought researchers wanted. However, he adds this is unlikely given that people who give fake positives tend to give them across the board, and these teens did not fill out their surveys in a way that would suggest they were doing so.

Goldfield says that there are lot of biological and genetic factors that influence weight and shape, and that this study’s empowering message is that fitness is a better predictor of psychosocial benefits than weight loss or change in body fat.

“Throw away the scale, don’t worry about losing weight,” he says. “This study is showing that if you do get modest amounts of physical activity-a couple hours a week-you can improve mental health even if you don’t lose weight.”