Synthesizes and secretes leptin involved in appetite regulation ??? ??? ??? body composition proportions of muscle, bone, fat, and other tissue that make up a person's total body weight ??? ??? ??? obesity (BMI range) overfatness with adverse health effects, BMI 30 or higher ??? ??? ??? when does underweightness threaten a person? during a famine or when they have to fight a disease ??? ??? ??? wa