Did they control against non diet soda drinkers or non soda drinkers in general? Wasn’t clear from reading the summary. There’s a whole lot of other indicator

Did they control against non diet soda drinkers or non soda drinkers in general? Wasn’t clear from reading the summary. There’s a whole lot of other indicators that could be linked with soda drinkers (education, income etc), so unless the only variable was diet vs not, consider me skeptical.