How healthy lifestyle research worked

The Bayer participants were 34-70 years old, were 93 percent white, and evenly divided male and female. They were considered eligible if they were overweight with pre-diabetes and/or metabolic syndrome.

The primary outcome measured was the change in weight between the start and six months later. Secondary outcomes were BMI, physical activity, HbA1c (blood glucose levels over a period of time), fasting glucose, serum insulin and lipids, blood pressure and waist circumference.

About 91 percent of the first intervention group on average attended 12 out of 16 sessions. (Combining all of the groups together, they attended a median of 12.5 of the 16 sessions and a median of two of the six later support sessions.)

At six months, 45 percent of the first intervention group lost at least 5 percent of body weight, compared to just 1 percent of the delayed group. Once they were combined, at the 12-month mark, there were improvements in mean weight loss (5 percent), the other health markers and increased physical activity. Similar results for the face-to-face and the DVD participants were reported.

At the 18-month assessment, just weight, waists and physical activity were measured. Of the 62 people who participated at that point, a mean drop of 8.6 pounds (4.2 percent drop in weight), an almost 2-inch reduction at the waist (3.9 percent) and an increase of 25 minutes of activity per week were reported.

The study noted that the results relied on participation by people who were already motivated to improve their health, and they reported on their own how much physical activity they had each week.

Related research

Andrea Kriska, epidemiologist at the University of Pittsburgh Graduate School of Public Health, is also senior author of a recent study analyzing information from the original Diabetes Prevention Program and its 2002 results, which found in addition to weight loss, increased physical activity and reduced risk for diabetes and heart disease, participants in the lifestyle intervention group reduced their combined TV and work sitting time — an average of almost sevenhoursaday—by37minutes a day. That was about a half-hour more than the other two groups in the study, one taking a diabetes drug and the other, a placebo pill.

Ms. Kriska and her Pitt colleagues, including co-investigator Kaye Kramer, recently received a $3 million grant from the National Institutes of Health to test a new version of the Group Lifestyle Balance program. It will focus on encouraging sedentary, overweight adults to sit less, instead of increasing physical activity.