NEW YORK (AP) — Preston Cabral eats meat nearly every day at home, but his favorite meals at school are served on “Meatless Mondays” and “Vegan Fridays.” “Today I ate chips, tangerines and this thing that looked like chili but without the meat — just beans,” the 12-year-old said after lunch. Programs like these are among the few proven to work for one of the thorniest problems of the 21st century: How to get people to eat less meat. Experts agree that the urgency of climate change and the demands of a surging global population call for an overhaul of...