Question

5. A study fed one group of rats a diet that included yogurt sweetened with sugar, and another group of rats a diet that included yogurt sweetened with a zero-calorie artificial sweetener commonly found in diet cola. The rats that were fed a zero-calorie sweetener gained more weight and more body fat compared to the rats that were fed sugar. After the study was published, many news articles discussed the implication that people who drink diet soda gain more weight. Explain why we cannot conclude that this is necessarily true.

Answer 1

We cannot conclude that people who drink diet soda gain more weight is necessarily true because there are many factors other than drinking diet soda for weight gain such as genetics (children of obese parents are more likely to become obese), food habits, hormonal changes etc. In this experimentation, it is not clearly written that such confounding variables are controlled throughout the experimentation.