Malnutrition refers to deficiencies or excesses in nutrient intake, imbalance of essential nutrients or impaired nutrient utilization. The double burden of malnutrition consists of both undernutrition and overnutrition, as well as diet-related noncommunicable diseases. Undernutrition manifests in four broad forms: wasting, stunting, underweight, and micronutrient deficiencies. In 2020 globally, stunting affected an estimated 22.0% or 149.2 million children under 5 , wasting continued to threaten the lives of an estimated 6.7 % or 45.4 million children under 5 and estimated 5.7 % or 38.9 million children under 5 were affected by overweight. and about 53% of stunting, 70% of wasting and 48% of overweight children under 5 live in Asia. Undernutrition always begin with undernourishment means that a person is not able to acquire enough food to meet the daily minimum dietary energy requirements. FAO defines hunger as being synonymous with chronic undernourishment. Poor weight gain, also called "weight faltering or " slow weight gain " refers to failure to gain weight appropriately is the first sign of undernourishment, without any intervention may be affected linear growth and head circumference also. The underlying cause of poor weight gain is "always insufficient usable nutrition," due to wide variety of insufficient nutrition consumption such as poverty, neglected and ignorancy or increased nutrition requirement such as recurrent infection or specific medical condition such as prematurity, food allergy, inborn errors of metabolism. etc. which need Food for Special Medically Purposes. Principle treatment of undenutrition are nutritional treatment and early detection redflags and prompt treatment. Following the WHO guidelines 2007 for catch-up growth, the focus of dietary management during undernutrition has changed from supplementing only with energy to optimizing catch-up by providing adequate energy and protein. These guidelines suggest that 8.9–11.5% of energy should be supplied as protein, to provide optimal catch-up growth of lean and fat mass (from 10 g/kg/day, 8.9 PE% to 20 g/kg/day, 11.5 PE%; 73:27 lean:fat mass). The importance of a correct protein:energy ratio has also been highlighted by several recent studies investigating optimal oral/enteral feeds for catch-up growth. The protein requirement should content complete and sufficient essential aminoacids. In Indonesia, stunting is the most prevalent children underfive malnutrition, it is suspected due to only 38% children 6-24 months who consumed animal sources protein, Pilot study in one village consist of dietary conselling to eat animal sources foods every meals minimal 1 egg per day plus referral system to GPs or Pediatrician for every malnourished children screened in community health post to interference with detection & prompt treatment redflags plus nutritional treatment, successfully reduced stunting prevalence about 8,4% in 6 months.