Advice supporting regular physical activity, healthy food choices and smoking avoidance is definitely warranted in adolescents, particularly where early negative eating trends are evident. A difference in emphasis may be required for males and females with respect to physical activity and diet. The amount of dietary fat is important in maintaining energy balance, and the type of fat is important in reducing the development of heart disease. Low-fat foods are suitable at this lifestage, but it is also important to avoid sources of "hidden" saturated fatty acids (biscuits and fast foods) and to include sources of polyunsaturated and monounsaturated fatty acids (oils, margarine, lean meat, poultry and nuts).