NUTRITIONAL DISORDERS Dr. Saleem Shaikh Introduction Nutritional imbalance or disorders in a society generally depends on the socioeconomic conditions. In developed countries problems are related to over eating and obesity and in underdeveloped or developing countries chronic malnutrition is a serious health risk, particularly in children. For good health, humans require energy providing nutrients (proteins,fats and carbohydrates), vitamins, minerals, water and non-essential nutrients Energy: the requirement of energy by the body is calculated in Kcal per day. Inorder to maintain stable weight the energy intake should match the energy output. The average requirement for an individual is calculated by the formula: 900+10w for male and 700+7w for females; (w= weight in kgs) The obtained number is then multiplied by 1.2,1.4 or 1.8 depending on the physical activity of the person. Proteins: dietary proteins provide the body with amino acids for endogenous protein synthesis and are also a metabolic fuel for energy. Some amino acids are not synthesized in the body, these are known as essential amino acids. (1g of protein provides 4Kcal of energy) Fats: fats and fatty acids should constitute not more than 35% of diet. 1g fat provides 9Kcal of energy. Carbohydrates: Dietary carbohydrates are the major source of calories, especially for the brain. 1g provides for 4 Kcal of energy. Atleast 55% of the caloric intake should be derived fro carbohydrates. Vitamins: these are mainly derived from exogenous sources and are essential for normal structure and functions of cells. Minerals: iron, calcium, phophorus, zinc, coper, iodine etc are very essential for health and deficiencies may result in a variety of syndromes. Water: very important – 1-1.5ml per K al of energy spent. Pathogenesis of deficiency diseases. Nutritional deficiency develops when the essential nutrients are not provided adequately to the cells. Nutritional deficiency may be of two types: 1. primary – due to decreased amount in diet. 2. secondary – due to various factors like * interference with ingestion * interference with absorption * interference with utilisation * increased excretion * increased demand Obesity Dietary imbalance and over nutrition may lead to obesity. Obesity is an excess of adipose tissue that imparts a health risk, a body weight of 20% weight over ideal weight for age, sex and height is considered a health risk. Body mass index (BMI) – most widely used method; weight in kgs / height in m2. a BMI value of over 30 is considered obese. Obesity results when caloric intake is more than energy output This may be due to – over eating, sedentary life style, carbohydrate and fat rich diet, genetic predisposition and underlying diseases (cushings disease, hypothyroidism etc) Starvation is a state of overall deprivation of nutrients. Protien-Energy Malnutrition [PEM]: inadequate consumption of protein as a result of primary deficiency or due to secondary deficiency may cause loss of body mass and adipose tissue. Two variants of PEM 1. Kwashiorkor – deficiency of only protein, although the caloric intake may be sufficient 2. Marasmus: starvation in infants occouring due to overall lack of calories. Vitamins Vitamins are organic substances which cannot be synthesized within the body and are essential for maintenance of normal structure and functions of cells. Classification of vitamins: vitamins can be divided into 2 groups - Fat soluble and Water soluble Fat soluble: there are four fat soluble vitamins – A,D,E & K. these are absorbed from the small intestine in presence of bile salts. Water soluble: vitamin C and B complex. Easily absorbed from small intestine. Being water soluble these are more easily lost by cooking or processing of food. Vit A Vit D Vit E Vit K Water soluble vitamins