Do sugar-sweetened drinks drive obesity?

Obesity has been linked in media coverage to the drinking of too many sugar-sweetened beverages. Emotions are running high, but is there enough scientific evidence to conclude that consuming fewer sugary drinks will reduce obesity?

The Obesity Society opened its annual meeting, Obesity 2012, this week in San Antonio with a debate on that very subject.

In the debate, David Allison, Ph.D., associate dean for science within the UAB School of Public Health and director of the NIH-funded UAB Nutrition Obesity Research Center, faced off against Frank Hu, M.D., Ph.D., professor of Nutrition and Epidemiology at Harvard School of Public Health.

Allison sat down with The Mix to comment on the debate and on related studies just published in the New England Journal of Medicine.

Show notes on the interview

1:25 Sugar-sweetened beverages have figured centrally in public health discussions about obesity for more than a decade. Some evidence has suggested that such drinks may play a unique role. What’s needed now, says Allison, are rigorous studies to prove (or disprove) that reducing consumption of these beverages actually increases weight loss or slows weight gain.

2:02 Public health as a field changed over the last decade as the obesity epidemic became more evident. Advocacy has wrestled with purely scientific discussion, and emotions are running high.

3:44 Valid, scientific study results are a must when deciding whether or not any one factor contributes to, or reduces, obesity, and the standard for that validity is a randomized clinical trial.

4:38 Up until the meeting, the evidence has not been there to demonstrate that reducing sugar-sweetened beverage intake would reduce obesity, according to Allison. In six of the six randomized clinical trials to date, he argues, the primary analysis of all patients studied showed no statistically significant difference in weight gain, weight loss or BMI between those who kept drinking sugary drinks and those who cut back.

5:26 On top of the six clinical trials mentioned, however, a series of papers were just this minute published in the New England Journal of Medicine. Two of the studies — one in children, one in adolescents — did indeed represent the kind of randomized clinical trials Allison has been calling for. The authors of both studies offer valid evidence, Allison says, that reducing consumption of sugar-sweetened beverages reduced weight gain in specific groups under certain conditions, but more studies are needed to confirm that the patterns apply to everyone.

9:23 While sugar-sweetened beverages remain an important area of inquiry, Allison says he thinks other emerging thrusts in obesity research warrant attention as well. These include the roles of sleep, daily weigh-ins and eating vs. skipping breakfast.

10:32 UAB’s Nutrition Obesity Research Center has joined with six other NORCS and a center in Denmark to organize a randomized clinical trial in 300 patients to generate evidence that having or skipping breakfast in the morning affects body weight.

11:36 UAB meeting highlights beyond the presidential debate included a presentation by Nefertiti Durant, M.D., assistant professor in the UAB School of Medicine's Division of General Pediatrics and Adolescent Medicine, as part of a symposium on adjusting obesity prevention approaches to account for a person’s age. Her talk, titled “Freshman 15 and Beyond,” discussed contributing factors and potential solutions. In addition, James Rimmer, Ph.D., Lakeshore Foundation Endowed Chair in Health Promotion and Rehabilitation Sciences in the UAB School of Health Professions, will be talking about how people with intellectual disabilities have higher rates of obesity than the general public based on several factors, including their living arrangements.

13:10 For good information on obesity, Allison recommends the Weight-control Information Network organized by the National Institute of Diabetes and Digestive and Kidney Diseases. He also points to the U.S. Agriculture Department’s Dietary Health page. For researchers, Allison offers the UAB NORC’s seminar series, which is available to all online, goes back 12 years and discusses a great many aspects of nutrition theory and related scientific evidence.

Also important is a recent editorial in the Journal of the American Medical Association by the director of the National Institutes of Health, Francis Collins, M.D., Ph.D. Of the editorial, which argues that public policy must be founded on valid science, Dr. Allison says he couldn’t agree more.

14:22 End podcast

About the podcaster

Greg Williams @gregscience @themixuab is research editor within Media Relations at the University of Alabama at Birmingham.