1. Energy Balance

2.  BMR is predicted by lean body mass (i.e. total body mass - fat mass), and varies with gender and age.  Extra metabolic energy is consumed during growth, pregnancy and lactation, and when febrile.  The second component of energy expenditure is determined by the level of muscular activity; this is highly variable according to occupation and lifestyle.  DAILY ENERGYREQUIREMENTS. female male At rest (1600 kcal) (2000 kcal) Light work (2000 kcal) (2700 kcal) Heavy work (2250 kcal) (3500 kcal)

3. Nutritional Assessment DIETARY HISTORY A review of the patient's lifestyle, including an assessment of physical activity level and eating habits, may help provide information about energy balance. A family history of obesity, A careful medication history and social history may help the clinician identify precipitating factors that can be modified to enhance the success of treatment. Weight loss more than 5% of usual weight, should prompt efforts to diagnose the underlying disorder or social circumstance Weight loss in excess of 10% of usual weight should be considered to represent protein-energy malnutrition that will impair physiologic function, particularly muscle strength and endurance

4. Weighing ( weight loss= water loss?, fat loss?, muscle mass loss) Approximately 50% of body fat is subcutaneous. The use of skinfold calipers to define the triceps skinfold (TSF) is the most practical technique to estimate body fat Changes of body weight reflects the water and /or energy (calorie) balance Loss of subcutaneous fat and skeletal muscle is manifested by sunken temples, thin extremities, wasting of the muscles of the hand, and, rarely, edema. Coexisting illness my obscure or confuse signs of malnutrition body mass index =(weight /height 2 ) kg/m 2 <18.5 ………underweight 18.5-24.9 …….normal 25-29.9..……..overweight 30.0-39.9 ……..obese >40 ……………….morbid obesity Clinical Examination

5. Laboratory Investigation Give info. About protein deficiency Plasma albumen (1/2 life 18 days) reflects visceral protein depletion but represents: synthetic rate, distribution in body pool and tissue catabolism or loss from the body : hypoalbuminemia does not merely equals protein malnutrition Injury, inflammation and liver disease reduce albumen (negative phase reactant) additionally increased plasma volume [CHF,CRF,CLD] even with ample intake The ratio of serum albumin to C-reactive protein (positive phase reactant) gives better estimate of protein depletion Plasma transferrin(1/2 life 1 wk ) and pre albumin(1/2 life 2 days) are more sensitive indices of visceral protein status Urinary nitrogen reveals degree of protein catabolism Biochemical tests for micronutrients (serum B12,RBC folate and serum ferritin )