system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why is being overweight so much more common now than it was 40 years ago?
gpt
A few reasons.  Food has gotten a lot cheaper, and as prices have decreased most restaurants simply increased how much food they give you rather than lowered prices.  It's cheaper and/or less time consuming to eat unhealthy foods than healthy foods, which impacts lower income people who have to work more than one job.  With TV, computers, video games, and other reasons people are moving around and getting exercise a lot less than they used to, but eating more because of the previous reasons.