A weight reduction diet with 700 kcal (90 g protein, 50 g carbohydrates and 15 g fat) and one to two intermittent fasting days per week proved successful for 15 obese, physically inactive adolescents: weight loss averaged 31.4 lb. within 4 months. Intensive dietary instructions of youngsters with their mothers were carried out on an individual basis, with weekly follow-up visits and review of dietary diaries. In contrast, a group therapy approach toward obesity control in 27 adolescents with the help of former adolescent patients as ‘instructors’ proved disappointing (average loss of 10 lb. within 2 months). Reasons for a lower success rate were boredom of three long summer vacation months, lack of transportation, frequent disinterest among the families and disruptive family units, ignorance in basic knowledge about nutrition and failure to take advantage of previous experience of other adolescents who had completed their weight reduction.