To the long and growing list of risk factors known to increase the risk of obesity, scientists recently added a new one: scarcity.
People given subtle cues that they may have to confront harsh conditions in the near future choose to eat higher-calorie food than they might do otherwise, a response that researchers believe is shaped by the long hand of evolution.
Many big food companies are caught in a dilemma these days. They want to rebrand themselves as merchants of health — Coca-Cola's new anti-obesity ads are just the latest example — but many of their profits still come from products that make nutritionists scowl.
If there's one person who symbolizes this tension, it's Derek Yach.