I personally think the barriers are psychological while the ones who experience the barriers my think it is purely financial.
Michelle and LaRue made good points in that there really aren’t too many barriers if people are properly educated about their choices in exercise and food.
I don’t live in a high income neighborhood, but where I do live has lots of corner stores, take out places and zero gyms. Within walking distance are 2 high school tracks but people need to know what to do when they get there. Also within that same radius are two supermarkets, one much better than the other. The issue then becomes, when you go to the market, what do you buy?
When we start to focus on the people then we can find out what is really keeping them from making better choices.