The World Health Organization (WHO) defines malnutrition as “the cellular imbalance between the supply of nutrients and energy and the body's demand for them to ensure growth, maintenance and specific functions”. This imbalance includes both inadequate and excessive energy intake; the former leads to malnutrition in the form of wasting, stunting and underweight, and the latter leads to overweight and obesity. Macronutrient and micronutrient deficiencies adversely affect growth, body composition, muscle strength, intelligence, body development and quality of life in children. age group. In children, undernutrition manifests as underweight and stunted growth (short stature), while severely malnourished children exhibit symptoms and signs that characterize conditions known as kwashiorkor, marasmus. or marasmic-kwashiorkor. Malnutrition generally involves undernutrition and refers to any deviations from adequate and optimal nutritional status in infants, children and adults. Deficiencies of macronutrients such as protein, carbohydrates and fats cause protein-calorie malnutrition (PCM) and when combined with micronutrient deficiencies constitute one of the most significant nutritional problems with hundreds millions of pregnant women, the elderly and young children are particularly affected. Malnutrition is one of the most important underlying causes of infant mortality in developing countries, particularly during the first 5 years of life (Pelletier, DL, 1995), the leading causes of infant mortality. these are poverty, global conflicts, lack of education, natural disasters and poor access to healthcare. PCD typically presents early in children aged 6 months to 2 years and is associated with early, delayed weaning...... middle of paper ......0.41. Malnutrition has lifelong implications because it significantly reduces a child's ability to learn and develop to their full potential and leads to less productive adults, poor performance and wasted government resources. Some research and studies have proven that the relationship between infection and malnutrition is bidirectional 36,37. Various mechanisms cause impaired immunity due to malnutrition, leading to increased susceptibility to infections. On the other hand, infection causes loss of important micro and macro nutrients, resulting in altered nutritional levels. Malnourished children contract gastrointestinal and respiratory bacterial infections more frequently. 42. Malnutrition significantly compromises the mucosal epithelial barriers of the gastrointestinal, respiratory and urogenital tracts, which constitute the first line of defense against infections..