By Kathleen Struck
A review of published studies investigating a possible link between sugar-sweetened beverages and obesity found that studies funded by the beverage industry were likely to find little evidence that sodas and juices fuel obesity.
Among 17 reviews analyzed, four industry-funded studies concluded that the causal relationship between sugary drinks and body weight was weak versus 13 independent studies that concluded the link between sweetened beverages and obesity was well founded.
Philippe De Wals, M.D., Ph.D., of Laval University, Quebec City, Quebec, and colleagues, reported the results of their review at “European Congress on Obesity,” which is meeting this week in Liverpool, England.
“Results support the hypothesis of a master plan, based on subtle intervention, that has been developed by the food industry to instill doubt regarding the adverse effects of [sugar-sweetened beverages] and to prevent the implementation of public health interventions and policies aiming to reduce their consumption,” De Wals said in a press release.
The researchers included reviewed 17 published studies — three meta-analyses, three qualitative systematic reviews and 11 qualitative nonsystematic reviews — in the analysis, researchers stated.
The quality of the studies’ methodology was assessed using “A Measurement Tool to Assess Systematic Reviews (AMSTAR)” and the American Dietetic Association “Quality Criteria Checklist (ADA-QCC)” scales.
“The scientific quality of the reviews were not correlated with the source of funding,” they wrote.
Eleven experts blindly assessed the study authors’ position using a 5-point Likert scale with 0 signifying no evidence of causal relationship and 5, used to indicate a strong causal relationship.
“‘Master plan’ or no, efforts by industry elements to obscure the link between soda and health outcomes are in the interests of shareholders, but certainly not the public health,” commented David L. Katz, M.D., M.P.H. of Yale University in an email.
“Even in the absence of data, a mean application of logic shows that soda cannot be good for our diets, health, and waistlines,” Katz stated. “But we do, indeed, have data to corroborate this self-evident reasoning. Whether or not the beverage industry has a coordinated master plan to obscure the association between soda and obesity, they certainly are motivated to downplay the importance of the relationship.”
But Katz acknowledged that soda is not solely responsible for the nation’s ‘obesity epidemic,’ noting more sugar comes with food than drink. However, he stated, calories from sugar-sweetened drinks harm the overall quality of the American diet.