Famine causes weight loss in adults and stunted growth in children. If the famine continues for any length of time, malnutrition starts to cause an increase in mortality. The young and the old tend to die first, and often diseases kill more individuals than overt starvation. Mass migrations may occur in response to famines.
In addition to the biological effects of famine, famine causes structural breakdown of society and may lead to dramatic transformations in cultural practices, religions and the structure of government.
Healthy adults are quite resistant to reductions in food intake. Cutting the normal caloric intake in half reduces a person's body weight by 25 percent, but adults can live for considerable periods of time in this state. Reducing the caloric intake even further results in reduced resistance to disease. Adults who survive a period of severely reduced caloric intake are generally able to recover fully when adequate nutrition is restored.
Children subjected to severe caloric restriction during a famine are often permanently affected, both physically and mentally, even after adequate nutrition is restored. Child survivors of famine experience stunted growth, with an average reduction in adult height of 1.1 inches. There are mental effects as well, with famine survivors attaining 6.8 fewer years of education. Ability to work as an adult is also reduced by an average of 12.6 hours per week.