JAMA Study: Two specific methods prevented weight gain in young adults for three years

May 2, 2016

A new study co-authored by a University of North Carolina Chapel Hill researcher found two specific diet and exercise strategies prevented weight gain and obesity among young adults over a sustained three-year period.

The multi-site study, published online May 2 in JAMA Internal Medicine, focused on young adults between the 18 and 34 years of age, a range where the potential for weight gain is highest. The study is titled “Innovative Self-Regulation Strategies Reduce Weight Gain in Young Adults: The Study of Novel Approaches to Weight Gain Prevention (SNAP) Randomized Controlled Trial.”

Dr. Deborah Tate

According to Deborah Tate, PhD, a professor in UNC’s Gillings School of Global Public Health’s Department of Health Behavior and Department of Nutrition and P.I. of the UNC study site, the two methods studied – the “daily Small Changes approach” and the
“periodic Large Changes approach” both resulted in prevention of weight gain over the three year study period and some weight loss. Tate collaborated on the study with Drs. Rena Wing and Mark Espeland and colleagues from Miriam Hospital in Providence, Rhode Island, and Wake Forest University School of Medicine.

Tate says that they also found one of the methods used in the study was demonstrably more effective than the other.

“Both the large changes and small changes methods were effective for preventing weight gain and obesity in young adults, though one was a bit more effective than the other,” Tate says. “The Large Changes approach, which as the name implies, involves making some significant changes to diet and exercise at the program’s outset, resulted in participants losing some weight initially and then maintaining that, which helped to buffer against weight gain for the full three years of the study. The Small Changes approach, also was beneficial but the amount of weight lost and subsequently kept off was less.”

As for the particulars of the methods and how the study was conducted, Tate said the participants were split into three groups: 200 making daily Small Changes; 197 doing initial Large Changes; and 202 a self-guided group who served as controls.

At the outset of the study, researchers met with both the Small Changes and Large Changes groups 10 times over a four-month period to develop the skills and an approach to diet and exercise to prevent weight gain during this high risk period.   One of the key elements of both approaches was daily weighing, to keep tabs on their weight and to guide diet and activity changes over time.

The Large Changes approach encouraged an initial weight loss to serve as a buffer against small gains that typically occur over young adulthood. It targeted a five pound weight loss for those in a normalhealthy BMI range and a 10 pound weight loss buffer for those above normalwho were overweight at study outset. The Large Change group reduced calories by 500 to 1,000 calories a day less than baseline levels for eight weeks while gradually increasing activity levels until they reached a goal of 250 minutes per week. They then were instructed to maintain exercise at this level for the course of the study.

The Small Change participants were given plans that reduced their diet by 100 calories per day from baseline and were encouraged to increase their activity by about 100 calories per day. They were given pedometers and instructed to add 2,000 steps of activity – or about one addition mile of walking – each day above their baseline levels, and to maintain those levels for the length of the study.

Assessments of all the participants’ weight, BMI and body composition occurred at the study’s outset, at the four-month point, and again at the one-, two- and three-year anniversary dates of the study’s inception.

What the researchers found was that both the Small and Large Change groups were able to prevent weight gain over three years.

“These findings are very important for public health, until now, we didn’t have clear guidance on what the message and recommendations should be for preventing weight gain.” Tate says. “This study showed that frequent weighing and either initial weight loss or daily small changes to both diet and activity resulted in successful weight gain prevention during a high risk period of adulthood. More importantly, due to the success of these programs, we received funding to continue them and to follow them to see the effects at six years.”

Gillings School of Global Public Health contact: David Pesci, director of communications, (919) 962-2600 or dpesci@unc.edu