Why do you become healthier when you eat better? Do your genes change at all?
Genes don’t suddenly change according to individual lifestyles, how we eat, when we eat etc. It takes millions of years of evolution for any kind of change in genes to occur.
However, what changes is the gene expression. For example, if you work out and lift weights, your muscle builds up due to expression of genes related to that. The gene itself doesn’t change. When you stop going to the gym, your muscle mass won’t stay the same because the genes are no longer required to express in that particular way.