Maria Ermelinda Ayme Sichigalo, a farmer and mother of eight, walks to a livestock market with her husband and children in Simiatug, Ecuador to sell sheep. (From the book What I Eat: Around the World in 80 Diets.) The caloric value of her typical day's worth of food in the month of September was 3800 kcals. She is 37 years of age 5 feet, 3 inches and 119 pounds. With no tables or chairs, Ermelinda cooks all the family's meals while kneeling over the hearth on the earthen floor, tending an open fire of sticks and straw. Guinea pigs that skitter about looking for scraps or spilled grain will eventually end up on the fire themselves when the family eats them for a holiday treat. Because there is no chimney, the beams and thatch roof are blackened by smoke. Unvented smoke from cooking fires accounts for a high level of respiratory disease and, in one study in rural Ecuador, was accountable for half of infant mortality.