This chapter examines the health risks that arise from excessive consumption of alcohol, drugs and other substances. It explains challenges that arise from the rising incidence of overweight and obesity in childhood and adolescence, health risks from excessive dieting, and major eating disorders, including anorexia nervosa and bulimia nervosa. The chapter describes several initiatives to reverse childhood obesity by tackling both the social, psychological and physical environment of the child. By the time of adolescence, excluded children are more likely to drink regularly than non-excluded peers. The risks from solvent abuse are also severe, causing nausea, vomiting, blackouts and heart problems that can be fatal. The best methods involve training the children in social competencies, healthy decision-making and knowledge about the health outcomes of excessive use of drugs and alcohol. Obesity is one of the most common medical problems affecting children and adolescents in Western and developing countries.