I saw one story looking at elevated blood pressure and liver enzymes that are usually high with fatty liver being strongly predictive of a poor outcome--those cluster with overweight, but overweight isn't really necessary. Personally, my blood pressure went from sort of high to normal just switching to a low carb diet. With weight loss it went a bit lower, but the diet switch itself seems to have done most of the work, before there was much weight lost.

So maybe they said, A is a risk factor for B, B is a risk factor for C, so A is a risk factor for C. Which isn't always something you can get away with, if ever.