Give poor people money to buy food, they will likely optimize in fat+ ways. Pay people to be healthy. The needy can be healthy. Put a floor under everyone and then progressively incentivize health.
Health is its own reward; paying people for healthy _outcomes_ == worse poverty for the chronically unhealthy, partially disabled, and (in the US) victims of the non-healthcare system.
People need to eat every day. Give people cash, it goes for random things. Give people food stamp - at a minimum they have food. I'm guess you've never been hungry. The folks who invented food stamps were trying to reduce a real problem.