Few, if any. Obesity is defined as having a body mass index higher than 30—the equivalent of being about 5-foot-11 and 220 pounds. The best indicator of body type among prehistoric peoples is present-day societies with a similar lifestyle—that is, hunter-gatherers. From the San people of Botswana to the Pygmies in central Africa to the Batek of Malaysia, groups that fall into this category tend to be small and extremely thin. The Baka of Cameroon, for example, are about 5 feet tall and weigh around 105 pounds, giving them an average BMI of 20. Hunter-gatherers are usually thin because they subsist largely on fruits and vegetables, underground tubers, and, in some regions of Africa, honey. They also get calories from animal meat, and some of their diets are especially fish-heavy. But many tribes insist on distributing the meat evenly among the group, so there’s rarely enough for one person to get fat on. Hunter-gatherer tribes also stay thin, unsurprisingly, due to a generally active way of life.