That, in turn, would explain why women in rich countries, who are less likely to suffer from hunger and disease, are more likely to give birth to sons.

ECONOMIST: The sex of a child may depend on how stressed its mother is

They argue that it is easier to adhere to (proteins do indeed make people feel fuller for longer), and that they suffer from fewer of the hunger pangs and mood swings that are characteristic of low-fat diets.

ECONOMIST: Nutrition