Findings from French dermatologists suggest that maybe nana was right, and that those who overdo it on greasy, sugary foods are more likely to get acne.

People with acne are often reported to believe that the consumption of foods such as chocolate, fatty foods and milk affects their condition, point out the researchers from Paris 13 University. 

However, while the role of nutrition in adult acne has been hypothesised, data is scarce because of small sample and the frequent focus on teenage acne.

Their analysis of data from 24,500 adults involved in a cohort study called NutriNet-Sante showed those who consumed 100g of fatty or sugary products per day were 54% more likely to have acne.