Diet and exercise being by far the most important and lowest hanging fruit here is definitely true. But even so, what percentage of people do you think even have a rough idea of what an optimal diet+exercise routine would look like for themselves? Different fad diets have come in and out of fashion over the decades, and while some have had quite a bit of interesting research backing them, not all have.

Motivation is a difficult part, but I think we can help people out a lot by making accurate, personalized, and easily actionable information much more accessible to them.