1. Introduction Conclusions 1. From : Researcher Centre for Public Health Intervention Technology, National Institute of Health Research and Development MOH RI E-mail : Feriahmadi@yahoo.com, Fellysenewe@yahoo.comFeriahmadi@yahoo.comFellysenewe@yahoo.com We define obesity we use sex and age specific Body Mass Index by age, cut of point recommended by standard WHO 2007 these BMI by age 95 th percentiles, and underweight use the BMI by age 5 th percentiles. The methodology Cross Sectional Study and methods sampling use to two stage sampling. We spread from 440 districts from 33 provinces in Indonesia. The data used comes from data Health Research Basic Survey ( Riskesdas 2007 ) from NIHRD MOH RI TREND OF OBESITY AND UNDERWEIGHT IN OLDER CHILDREN AND ADOLEST IN INDONESIA Authors: Feri Ahmadi, MPH. 1 and Dr. Felly Philipus Senewe, M.Kes. 1 17-18 November 2011, Bali No. 158/NCD/POSTER/2011 Growth and development of children is determined by environmental factors, food intake, and disease. The most common cause of a person being underweight is primarily malnutrition caused by the unavailability of adequate food. The effects of primary malnutrition may be amplified by disease, others due to poverty. Obesity is a medical condition in which excess body fat has accumulated to the extent that it may have an adverse effect on health, leading to reduced life expectancy and/or increased health problems. Body Mass Index (BMI), a measurement which compares weight and height, defines people as underweight when it is less than < 18,5 kg/m 2 and overweight (pre-obese) if their BMI is between 25 and 30 kg/m 2, and obese when it is greater than 30 kg/m. Study about obesity and underweight to cover all provinces, the data from Health Research Basic Survey ( Riskesdas 2007 ), we examined the trends of obesity and underweight in young person aged 6-18 years. Methods & Materials Results The prevalence’s of underweight group male 19.0%, and group female 15.5%. The prevalence of obesity group male 13,6 %, and group female 12,2%. Aged 6-11 years, weight and obesity problem is still relatively high, while the age of 12 years, gradually prevalance of weight and obesity, it is because of the diet, as well as other activities. Figure 1: Nutritional status Male by Age Figure 2: Nutritional status female by Age Figure 3: Nutritional status by province’s Age Prevalence Key Words : Obesity. Underweight. Children. Adolescents. Indonesia The burden of nutritional problems is shifting from energy imbalance deficiency to excess among older children and adolescent. Nutritional Status Abstract : Nutrition problems in Indonesia are obesity and underweight, factor is intake food, physical activity. To find out the use to standard WHO 2007 these BMI by age, which are used as for ages 6-18 years. Data used Riskesdas 2007 from NIHRD MOH RI.The analysis can be started from the age of 6-11 years the prevalence of obesity and underweight were both quite high and decreases in the age of 12 years and over this is due to changes in diet and activity, and nutritional status by gender. Abstract :