This is a myth, and simply not true. There was a time, decades ago that it was true, but those days are long gone. These days it's just propaganda spread by the social welfare industry to justify their jobs and socialist teachers/professors to sell socialism to the gullible. Between food stamps, WIC, school lunches, and church group food giveaways no child in America need go hungry. The fact is that adult and childhood obesity are a much bigger problems in poor households than hunger. Unfortunately some drug addicted poor do sell a portion of their government aid to pay for drugs but throwing more money at that problem just goes to pay for more drugs not more food.
As for child labor laws, I had a job all through high school and I managed to graduate with not only a far better understanding of mathematics, chemistry, literature, civics, personal finance, and history than today's average HS grad, but with a trade and good well established work habits that allowed me to hit the ground running. I also worked my way through college and graduated with a degree in something useful and marketable and no debt. Back then lots of HS kids had summer jobs in the food, construction, or auto repair industries and graduated with good solid work habits and a resume and a car they paid for themselves. The fact remains that any able bodied person of reasonable intelligence can work their way into the middle class if they are willing to put in the effort and take less than glamorous jobs. Sadly, way too many people aren't willing to put in that effort or get their hands dirty. And others decided to spend 4-6 years and $100K in debt getting a college degree in thumb twiddling and whining about the successful only to find themselves barely qualified for a job at Starbucks. Neither are the fault of the successful or successful companies and their working class IRA and 401k investors.