Western disease and sugar heavy diets broadly speaking, which Semaglutide is a countermeasure against. Not yet a vaccine, but in due time (probably via gene therapy).

As is being sedentary - there are probably lots of interconnected factors in play, and GLP-1 receptor agonists seem to help with more than one (perhaps even many) of them.

Unpicking the exact chains of causation is likely going to be extremely complex, but the general picture continues to look good.