I work developing medical information technology. But some of the most important health issues could be addressed by building our physical living spaces to encourage health. Most of our "built environment" encourages driving and not walking for bicycling. We have a serious and growing problem with diabetes which is encourage by our collective lack of movement. We are actually paying and regulating for this problem in many ways. We subsidize driving by using payroll tax money to make free public roads, the cost of roads should be placed on driving itself so that roads get built where the most people use them. Many places limit building height which makes housing, work and shopping too spread out to use anything but a car. We regulate single use zones for housing, offices and working putting everywhere we want to go far apart and only accessible by car. Then we pay again with poor health and increased health insurance premiums.
Often the only way to get any exercise is too pay for a health club membership, drive your car through the outdoors at more expense for gas, then get on an exercise machine with a video simulation of the outdoors you just drove through. This takes time, money, and motivation that few of us have to exercise.
I know people want more walkable neighborhoods because the most walkable places to live are always the most expensive. That means we are competing to live there. So let's build more of these places. It should be easy because all we have to do is stop regulating against denser, higher floor buildings and mixed use development. Developers should want to build these places because rents and sales prices of the buildings will be higher than car dependent development. This would make getting a walk in easier for everyone and save us all the pain and costs of poorer health basically for free.
When we make taller buildings we could actually give ourselves more green space. Make the buildings taller but then put larger parks, playgrounds, gardens, and sports fields between them. This would put us closer to nature even though we are living in taller buildings, provide sunlight, encourage walking and bicycling more, improving our health and environment.