Eney AE, et al. – This research scrutinized the proposition that the link between soda consumption and body mass index (BMI) would be significant both between and within twins. The data illustrated that increased soda consumption correlated with increased BMI, among a large group of adult twin pairs. Nonetheless, the observed association was mediated by a genetic background, common to both.

Methods

• The scheme of this research was a cross sectional study.
• It constituted 5787 same sex adult twin pairs (18-97 years, 66% female) from the community based Washington State Twin Registry.
• Structural equation modeling (SEM) inspected the link between soda consumption and BMI in the population (the phenotypic association between exposure and outcome among all twins treated as individuals) and within pairs of identical and fraternal twins (the quasi-causal association controlling for between pair genetic and environmental confounds).

Results

• A prominent phenotypic correlation was noted between soda consumption and BMI that held when controlling for age, sex, race, annual household income, and education level (P < 0.05), among all twins.
• Nevertheless, the effect of soda consumption on BMI appeared to be greatly reduced and was no longer prominent, with a large genetic confound in both men and women (P < 0.05), in the quasi-causal model.