>I'd like to have an app that estimates the cost of groceries, including the long term health effects of regular consumption, and interpreting early death as a cost rather than savings. For me I think ribeye would end up being cheaper than Doritos.

Someone who bothers to input everything they eat into an app (basically calorie counting) probably already has enough intuitive sense of what's "healthy" that they don't need an app that they should eat beef rather than doritos.