What can we do to keep people from gaining more weight?
During a plane ride, Sara Bleich watched a flight attendant take an overweight passenger’s drink order. The passenger asked for cranberry juice. “Cranberry juice is our highest-sugar beverage on the menu,” the flight attendant said. “Would you like a diet beverage?” “Just give me the cranberry juice,” the passenger said. As a public policy expert on obesity, Bleich, a Carol K. Pforzheimer Professor at the Radcliffe Institute and a professor at the Harvard T.H. Chan School of Public Health, knew that the flight attendant was right about the juice. At the same time, she admired the passenger’s pushback against fat-shaming. Here’s what Bleich wrestles with: We are almost powerless to fight an industry that profits from loading foods with sugar, salt, and unhealthful fats that we are hardwired to crave. Telling people what to eat — and what not to eat — often backfires. “We know that about a third of adults and a fifth...