Acne is, affecting over 80% of teenagers (aged 13–18 years) at some point. Estimates of prevalence vary depending on study populations and the method of assessment used.
Prevalence of acne in a community sample of 14–16 year olds has been recorded as 50% and it has been estimated that up to 30% of teenagers have acne of sufficient severity to require medical treatment.
There are some recent researches in this field like: Body mass index is negatively associated with acne lesion counts in Taiwanese women with post-adolescent acne. I can’t get access to the full text of this study, but it appears that researchers found evidence that heavier people have less acne than thin people.