A fresh study looks at what happens after people change their meat-eating habits. Those who upped their intake — about 3.5 servings more per week — saw their risk of developing Type 2 diabetes during four years of follow-up increase by almost 50 percent.
Thousands of years ago, ancient farmers gained the ability to consume milk as adults without getting an upset stomach. A remarkable mutation let some of them digest lactose sugar. But scientists still puzzle over why that mutation persisted and became prevalent in modern humans.