A defined exercise program significantly improved cardiometabolic health and body composition in children with overweight and obesity, but no effect was seen on mental health, based on data from 92 children.
Childhood obesity is associated with negative health outcomes including type 2 diabetes, cardiovascular disease, and mental health disorders, and exercise is considered essential to treatment, wrote Jairo H. Migueles, PhD, of the University of Grenada, Spain, and colleagues. However, the effect on children with obesity and overweight of an exercise program on physical and mental health, including within-individual changes, has not been well studied, they said.
In a study published in JAMA Network Open, the researchers reviewed data from 36 girls and 56 boys with overweight or obesity who were randomized to a 20-week exercise program with aerobic and resistance elements, or waitlisted to serve as controls. The participants ranged in age from 8 to 11 years with a mean age of 10 years. The data were collected between Nov. 1, 2014, and June 30, 2016, as part of a parallel-group randomized clinical trial. The exercise program consisted of three to five 90-minute exercise sessions per week for 20 weeks, and the control children continued their usual routines.
The main cardiometabolic outcomes measured in the study were divided into three categories: body composition, physical fitness, and traditional risk factors (waist circumference, blood lipid levels, glucose levels, insulin levels, and blood pressure).
A cardiometabolic risk score was defined by z score. The researchers also added cardiorespiratory fitness (CRF) to the cardiometabolic risk score. Mental health was assessed using composite standardized scores for psychological well-being and poor mental health.
After 20 weeks, cardiometabolic risk scores decreased by approximately 0.38 standard deviations in the exercise group compared with the control group. In addition, specific measures of cardiometabolic health improved significantly from baseline in the exercise group compared with control children for low-density lipoprotein (change of –7.00 mg/dL), body mass index (–5.9 kg/m2), fat mass index (−0.67), and visceral adipose tissue (31.44 g).
Cardiorespiratory fitness improved by 2.75 laps in the exercise group compared with control children. In addition, significantly more children in the exercise group showed meaningful changes (defined as individual changes of at least 0.2 SDs) compared with control children in measures of fat mass index (37 vs. 17, P < .001) and CRF performance (30 vs. 17, P = .03).
However, no significant effects appeared on mental health outcomes in exercisers, the researchers noted.
The reduction in cardiometabolic score was attributable mainly to improvements in cardiovascular fitness, blood lipid levels, and total and visceral adiposity, the researchers wrote in their discussion. The lack of changes in mental health measures may be a result of the healthy mental state of the children at the study outset, they said. “The null effect on mental health outcomes needs to be further investigated, including, among other things, whether the instruments are sensitive enough to detect changes and whether there is a ceiling effect in young children who might be mentally healthy overall,” they wrote.
The findings were limited by several factors, including the relatively small sample size and lack of blinding for some evaluators. However, the results show the potential of exercise programs to affect meaningful change and improve cardiometabolic health in overweight and obese children, although more research is needed to explore the effects of larger-scale and longer-lasting public health interventions combining exercise and other health behaviors such as diet, the researchers concluded.
Bottom line: Exercise works
The increasing rates of overweight and obesity in children in the United States have “significant downstream consequences that include increased risk of metabolic disease, including diabetes and hypertension, as well as increased rates of anxiety and depression,” Neil Skolnik, MD, professor of family and community medicine at the Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia, said in an interview.
Therefore, the effect of interventions such as exercise training on outcomes is important, he said.
The current study findings are “what you would hope for and expect – improvement in cardiometabolic parameters and fitness,” said Dr. Skolnik. “It was encouraging to see the effect of this relatively short duration of intervention has a clear positive effect on weight, BMI, and cardiometabolic parameters,” he said. “The real benefit, of course, comes from sustaining these habits over a long period of time.”
The lack of improvement in mental health is not surprising given the small study population “who did not have a high rate of mental health problems to begin with,” Dr. Skolnik added.
Barriers to promoting exercise programs for obese and overweight children in primary care are many, Dr. Skolnik said, including “having the motivation and funding to create programs like this so they are readily available to youth.”
However, the key message from the current study is simple and straightforward, according to Dr. Skolnik. “Exercise works! It works to improve fitness, cardiometabolic parameters, and weight control,” he said.
“There is always room for more research,” Dr. Skolnik added. The questions now are not about whether exercise benefits health; they are about figuring out how to implement the known benefits of exercise into daily living for all children, athletes and nonathletes alike, he said. “We need to find nonjudgmental ways to encourage exercise as a part of routine daily healthy living, up there with brushing teeth every day,” he emphasized.
The study was supported by grants from the Spanish Ministry of Economy and Competitiveness and El Fondo Europeo de Desarrollo Regional (FEDER) and by the MCIN (Ministerio de Ciencia e Innovación) / AEI (Agencia Estatal de Investigación. The researchers and Dr. Skolnik had no financial conflicts to disclose. Dr. Skolnik serves on the editorial advisory board of Family Practice News.
This article originally appeared on MDedge.com, part of the Medscape Professional Network.