Paleolithic peoples have often been called hunter-gatherers, but recent archaeological and anthropological research indicates that both historical and contemporary hunter-gatherers have depended much more on gathered foods than on hunted meat. Thus most scholars now call them foragers, a term that highlights the flexibility and adaptability in their search for food. Most of what foragers ate were plants, and much of the animal protein in their diet came from foods gathered or scavenged rather than hunted directly: insects, shellfish, small animals caught in traps, fish and other sea creatures caught in weirs and nets, and animals killed by other predators.

Paleolithic peoples did hunt large game. Groups working together forced animals over cliffs, threw spears, and, beginning about 15,000 B.C.E., used bows and atlatls to shoot projectiles so that they could stand farther away from their prey while hunting. The final retreat of the glaciers also occurred between 10,000 and 15,000 years ago, and the warming climate was less favorable to the very large mammals that had roamed the open spaces of many parts of the world. Wooly mammoths, mastodons, and wooly rhinos all died out in Eurasia in this megafaunal extinction, as did camels, horses, and sloths in the Americas and giant kangaroos and wombats in Australia. In many places, these extinctions occurred just about the time that modern humans appeared, and increasing numbers of scientists think that they were at least in part caused by human hunting.

Most foraging societies that exist today or did so until recently have some type of division of labor by sex, and also by age, with children and older people responsible for different tasks than adult men and women. Men are more often responsible for hunting and women for gathering plant and animal products. This has led scholars to assume that in Paleolithic society men were also responsible for hunting, and women for gathering.

Obtaining food was a constant preoccupation, but it was not a constant job. Studies of recent foragers indicate that, other than in times of environmental disasters such as prolonged droughts, people need only about ten to twenty hours a week to gather food and carry out the other tasks needed to survive, such as locating water and building shelters. Moreover, the diet of foragers is varied and nutritious. The slow pace of life and healthy diet did not mean that Paleolithic life spans approached those of the modern world, however. People avoided such contemporary killers as heart disease and diabetes, but they often died at young ages from injuries, infections, animal attacks, and interpersonal violence. Mothers and infants died in childbirth, and many children died before they reached adulthood.

Total human population thus grew very slowly during the Paleolithic. Moreover, the population was widely scattered, with small bands of people occupying very large territories. The low population density meant that human impact on the environment was relatively small, although still significant. In addition to contributing to the extinction of some large animals, Paleolithic people may have also shaped their environments by setting fires, which encouraged the growth of new plants and attracted animals that fed on them, making hunting or snaring game easier. This practice was a factor in the spread of plants that thrived best with occasional burning, such as the eucalyptus in Australia.