I'm not poor. But I came across a very illustrative example of how eating real food is more expensive this week.
Picture this: I'm grocery shopping with my 15 year old daughter (very expensive activity already). Serena: "Can we get mac'n cheese for snacks?"
Dad: "Ggrreghhg, unh, eg, those are expensive. Here, I'll show you."
I walked down the aisle to the pasta section, and picked out a 1 pound box of elbow macaroni* for $1.08, the cheapest I could find. Then back to the processed foods section and ... there's a half pound package of mac'n cheese for $0.49. OK, so it isn't really much cheese in there, but still. I'm losing at this stage.
On getting home I found a recipe for mac and cheese involving stirring and a microwave, and it was pronounced excellent fare, possibly even too rich to eat, and maybe as easy to make as the fake stuff. However it would have been even more expensive. The 1 cup of whole milk cost about $0.20, the 1 cup of mozzarella cheese about the same. Butter -- only a couple tablespoons but still not free.
To really make the comparison accurate I need to break it down by macronutrient value. The processed stuff has almost no fat, 49 g of carbohydrate, and only 8 g of protein in a serving. I used nutritiondata.self.com to figure out what my recipe has; scaled to have the same total amount of kcal as a serving of the processed stuff, I find 13 g of fat, 20 g net carbohydrate, and 11 g of protein. If you've given up on the fat=death paradigm, and embraced the carbs=death paradigm, then that is healthier than the processed stuff for sure. Still much more expensive per calorie and more expensive per gram of protein than the processed stuff. However, much cheaper per gram of fat. Hmmm.
So maybe there's hope that solving the obesity/diabetes epidemic doesn't mean eliminating poverty first.
*Note that I wouldn't eat this myself.