This seems like a case where things can be correlated without being causal. In other words, you can choose to drink soda, and make other decisions that lead to

This seems like a case where things can be correlated without being causal. In other words, you can choose to drink soda, and make other decisions that lead to obesity - the cause of both might be the same. (You might be hinting at that by saying they "drink soda because they are overweight" but I'd suggest that's inaccurate. As in, being overweight doesn't cause soda consumption!)