I don’t fully understand the whole “cheap food” issue. By shopping at standard grocery stores and about 30–45 minutes of cooking every other day, I can eat healthy, tasty, balanced meals for $2-$3/meal that include meat, veggies, and carbs.
Unfortunately, this way of eating doesn’t make it into books or internet fads because it’s not “sexy” food (chicken, a random green, and rice/noodles). However it’s an easy way to sustain a healthy diet.
I’m not sure how best to address the problem, but I would start with education.