“One thing he said is that the chemicals used in beef are horrible for health. He said the good news is they settle in the beef fat, so if you avoid the fat, you avoid most of the chemicals.”
If that was the cause, it would affect everyone who eats meat. Doesn’t. So it probably is not true.
I look for fat in meats - as marbling, not chunks along the side. It helps me to lose weight. Same with cheese. Every low fat diet I tried failed.
It’s interesting, based on individuals. If I eat cheese, my digestion shuts off.