While i get what you're getting at that is not true everywhere in America, in Nevada for example security jobs commonly pay 12-13 dollars an hour, is this higher than the state minimum wage of 10.50 and considered very low, yes, however there are still plenty of people working for those wages trying to support families.

If you're an average sized person your basic bodily functions, heart beating, liver filtering, brain thinking, all use anywhere between 1500-2000 calories a day. Speaking from experience an overweight 6'5" man burns 2500 calories if i just sit in bed reading a book all day