Summary by Neva Cochran, MS, RDN, LD
The Texas Academy of Nutrition and Dietetics Annual Conference in Houston April 12 – 14, 2018, featured Craig Johnston, PhD (pictured)as a speaker on “Finding the Answers to Childhood Obesity.” Dr. Johnston, an Associate Professor in the Department of Health and Human Performance at the University of Houston, discussed the childhood obesity problem and the successful behavioral programs he conducts in schools to find solutions to this ever-growing problem.
State of Childhood Obesity
Nationally, obesity has quadrupled over the last 25 years with 18.5% of children aged 2-19 obese. African American, Mexican American and Native American children have the highest prevalence of obesity. Texas currently ranks sixth among states in rates of childhood obesity. Not only are children experiencing health consequences from obesity at younger and younger ages – like a hip replacement in a 5 year old – but also psychological effects including discrimination and bullying related to their weight.
According to Dr. Johnston the Hispanic population is the fastest growing and largest minority group. When compared to non-Hispanic whites, Mexican-American children are more likely to be obese, have Type 2 diabetes and develop cardiovascular disease.
Middle schools were selected for an intervention with children 10 to 14 years old, specifically YES Prep, an open-enrollment public charter school system in Houston, Texas serving students in sixth through twelfth grade student in the city’s most underserved communities. Students were primarily low-income Hispanic and Mexican-American children with 80% receiving reduced or free lunches through the National School Lunch Program.
The study intervention was based on behavioral principles with daily student contact through a weekly nutrition class, four weekly physical activity sessions and a daily snack. The control group received the snack but spent the intervention time in study hall or health class.
The goals of the intervention were to increase health eating, decrease unhealthy eating, increase physical activity and decrease sedentary behaviors. The physical activity component was a modified circuit training in 30 – 45 minute class with 12 stations and one to two minutes at each station for activities enjoyed by children: jumping rope, throwing a Frisbee, and twirling a hula hoop.
The 35 – 40 minute weekly nutrition class taught students to make healthier food choices by reading labels and controlling portion sizes. Commonly eaten foods were grouped as “big bite” (fruits, vegetables) “portion right” (low-fat meats, low-fat dairy) and “little bite” (junk foods). Biweekly quizzes were administered and additional one-on-one education was provided for children with absences, low quiz grades, and/or continued weight gain for 2 weeks.
The study participants were encouraged to use low-calorie sweeteners, like sucralose (brand name Splenda), to increase the palatability of and adherence to the eating plan as well as provide a way for them to enjoy sweet foods with fewer calories. The researchers countered any objections to their use by delving into the research and verifying the support for their use by recognized health organizations like the Academy of Nutrition and Dietetics and the American Diabetes Association. Dr. Johnston also pointed out that only epidemiological studies, which are not designed to show cause and effect, link low calorie sweeteners to weight gain. In contrast, randomized controlled trials demonstrate that participants who consume low-calorie sweeteners lose weight, eat fewer desserts, report feeling less hungry, do not increase appetite and reduce intake of sugar-containing foods.
Registered dietitian/nutritionist Dr. Keith Ayoob (pictured), Associate Professor Emeritus at the Albert Einstein College of Medicine, who has worked with overweight children and families for over 30 years, likes this approach. “When the students learned about the safety and usefulness of low-calorie sweeteners, they were able to see them as valuable tools for supporting their weight-loss efforts.”
The intervention program participants significantly reduced BMI compared with the control group at both 3 months and 6 months and significantly reduced their percent body fat compared with controls at 6 months. (1) The intervention was successful for about two-thirds of the intervention participants. Even more encouraging was the continued progress after the program ended, with the intervention group continuing to decrease BMI at both the 1 year and 2 years while the control group did not. (2)
Dr. Johnston believes this program worked when so many others do not because the relationships built with the children changed the way they were thinking and they chose to live in a different way. In addition to weight changes, inflammation decreased and self-reported happiness and quality of life improved.
Dr. Ayoob agreed, and saw the study’s results as a game-changer the child obesity battle. “It showed that the right tools can help students permanently change their diets, eating behaviors, and lifestyle. But also their attitude about food and how they lived.”
Registered dietitian nutritionists were instrumental in facilitating long-term behavior change in this program, which contributed to its success. When the program was provided to PE teachers to use in a school setting, participants lost weight at 6 months but regained a large part of the weight back at one-year in contrast to the study program where they continued to lose. Therefore, Dr. Johnston empathized the need for trained healthcare professionals, like dietitians, to lead this program.
Incorporating lifestyle management strategies into school-based programs can lead to greater improvements in groups at higher risk for obesity. In this program in middle-school students from populations at risk for obesity:
Neva Cochran, MS, RDN, LD is a registered dietitian nutritionist based in Dallas. She serves as a nutrition communications consultant to a variety of food and nutrition organizations, including the Calorie Control Council. She is passionate about promoting fact-based food and nutrition information to help people enjoy nutritious eating. Follow her on Twitter @NevaRDLD and check out her blog at www.NevaCochranRD.com.