Unlike his brother, Grayson, Ethan Dolan does not eat dairy. This basically means cutting out all milk, yogurt, ice cream, cheese, butter, and any other dairy from your diet. Some say that cutting dairy products out of your diet can have an enormous impact on your health. Issues like nasal congestion, digestive problems, acne, or chronic ear infections may vanish within a few weeks. For Ethan, he was looking to improve his skin.
While some may think his new diet is because he is lactose intolerant, it is actually a personal choice. He made a beautifully-worded tweet about his diet change and said, “I don’t f**k with that dairy.”
From a string of tweets on Ethan’s feed, it seems like he stopped eating dairy to help with his skin issues. In another tweet, Ethan explained, “being honest, my skin got pretty bad for a little while and def made me insecure. If ur having problems with your skin 1. It’s not nearly as bad as you think 2. cutting dairy completely out of my diet has been the only thing that really worked & it makes u feel better all around.”
Source : https://www.distractify.com/p/are-the-dolan-twins-lactose-intolerant