Objectives: The health effects of added sugars have received much attention, but few studies have examined the association between foods that naturally contain sugar, such as 100% fruit juice, and risk of obesity and related conditions. Therefore, our purpose was to study the association between 100% fruit juice intake and risk of obesity and metabolic syndrome in a representative sample of the U.S. population.
Methods: Cross-sectional analysis of a multiethnic sample of U.S. adults from the National Health and Nutrition Examination Survey 1999-2004 was undertaken to examine the association between 100% fruit juice consumption and the odds of obesity (body mass index [BMI] ≥ 30 kg/m2) and metabolic syndrome (Adult Treatment Panel [ATP] III definition). We used logistic regression analysis to estimate the odds of obesity and metabolic syndrome per category of fruit juice consumption exposure, while adjusting for covariates that may be confounders of this association.
Results: Of 14,196 adults included in the sample, 3961 were consumers of fruit juice. Consumers of 100% fruit juice, relative to nonconsumers, had lower mean BMI, lower waist circumference, and lower homeostasis model assessment (HOMA) insulin resistance (p < 0.001). Level of intake (oz/d) had a linear inverse association with HOMA (p < 0.001), whereas the association with BMI and waist circumference was U-shaped (p < 0.001). Consumers relative to nonconsumers had 22% (95% confidence interval [CI] = 13%-30%) lower odds of obesity and 15% (95% CI = 10%-28%) lower odds of metabolic syndrome. After adjustment for demographics and lifestyle factors, the lower odds of obesity remained statistically significant, but a statistically significant reduction in odds of metabolic syndrome was no longer noted.
Conclusions: Compared with nonconsumers, those who consumed 100% fruit juice were leaner, were more insulin sensitive, and had lower odds of obesity and metabolic syndrome. The association with metabolic syndrome was explained primarily by other lifestyle factors, while the association with obesity remained independent. Experimental studies are needed to determine whether any direct physiologic link exists between consumption of 100% fruit juice and lower risks for obesity and metabolic syndrome.