Human Nutrition & Biochemical Parameters Of Nutrition PDF

HUMAN NUTRITION & BIOCHEMICAL PARAMETERS OF NUTRITION Dr. Halil RESMİ 25-31.12.2024  Science of Nutrition  The science of nutrition is concerned with;  The qualitative and quantitative aspects of the diet,  Utilization of dietary components requ...

HUMAN NUTRITION & BIOCHEMICAL PARAMETERS OF NUTRITION Dr. Halil RESMİ 25-31.12.2024  Science of Nutrition  The science of nutrition is concerned with;  The qualitative and quantitative aspects of the diet,  Utilization of dietary components required to sustain health. 2  Major Components  The major component groups required for human nutrition:  Carboydrates  Proteins  Lipids  Minerals Biochemically  Trace elements well defined  Vitamins  Fiber 3  Essential Nutrients  The biochemicals that cannot be synthesized in human body, must be provided in diet as nutritions,  These nutritions are termed essential and include the essential amino acids and fatty acids,  All water-soluble vitamins, as well as the fat-soluble vitamins A, E and K are essential,  Vitamin D is essential for children but not adults. 4  Essential amino acids 5 6   Variation in the requirement of nutrients depends on the age, sex, reproductive status, and on the altered nutritional demands associated with disease, injury and therapeutic interventions. 7  Energy Requirement  According to WHO, the level of energy intake that balance,  Energy expenditure  Body size  Body composition consistent with long-term good health. 10   In children and pregnant or lactating women, the ER includes the energy associated with the tissue development or the secretion of milk at rates consistent with good health.  The body is in energy balance when the metabolizable energy intake is equal to the sum of expenditure and changes in stored energy. 11  Basal Metabolic Rate (BMR)  Resting energy expenditure defined as an individual’s basal metabolic rate.  BMR makes up about 60-70% of the calories that the body uses (“burn” or expend).  This includes the energy that body uses to maintain the basic function of living and breathing such as:  The beating of heart  Cell proliferation  Respiration  The maintenance of body temperature  Circulation  Nutrient processing  The BMR, is influenced by a number of factors including age, weight, height, gender, environmental temperature, dieting, and exercise habits. 12  Determination of BMR  BMR can be determined by direct calorimetry (generation of heat),  Or indirect calorimetry (from measurement of oxygen consumption and carbon dioxide production). 13  Nitrogen Balance  An estimate of expenditure of endogenous energy can be quantitated from measurement of the nitrogen balance,  A positive balance is essential for growth (children and fetus), pregnancy and lactation and during physiologically stressful states. 14  Excessive nutrients  Excessive nutrients are stored as fat and extreme status of overnutrition can lead to obesity.  When insufficient nutrients is available, stored fats and muscle proteins are mobilized to supply energy and glucose. 15  Starvation  Starvation is defined as a severe deficiency in caloric energy intake needed to maintain human life.  It is the most extreme form of malnutrition.  In humans, prolonged starvation can cause permanent organ damage and eventually, death.  The basic cause of starvation is an imbalance between energy intake and energy expenditure. 16  Starvation vs. Hypermetabolic Status  Extreme lack of nutrients can lead to starvation.  Hormones and cytokines (such as TNFα) initiate a extreme metabolic response to an injury or infection that called hypermetabolic state,  Starvationa and hyprematabolic state are different situations.  While in starvation both fat stores and muscle are used as fuel, in hypercatabolic state the muscle protein is primary source of amino acids for gluconeogenesis. 17   Patient suffering from trauma, burns and sepsis often are in a hypermetabolic state within 1 to 2 weeks after an acute injury.  Observation associated with the hypermetabolic state;  Fever  Increased basal metabolic rate  Increased nutritional needs  Inceased heart rate and cardiac output  Negative nitrogen balance  Increased hepatic gluconeogenesis  Synthesis acute-phase proteins. 18  Carbohydrates  Carbohydrates are the principal source of energy for the body, contributing 50% to 60% of total calories.  Excessive carbohydrate intake;  body weight  Insufficient intake; stimulates mobilization of body fats, with associated ketosis, loss of electrolyte and dehydration.  One gram of carbohydrate provides 4 kcal (1kJ) of energy. 20  Protein Requirement  Dietary proteins are the source of amino acids, the building blocks of tissue proteins.  Some amino acids cannot be synthesized by the body (essential amino acids) and must be obtained in the diet.  The quality of dietary protein is determined by its content of all essential amino acids.  Essential amino acids should make up for;  Infants; 43%  Children 10 to 12 years old; 36%  Adults; 10% 21   Good-quality protein is required to replace losses during the hypermetabolic stress associated with fever, burns, fractures, surgical trauma, and other pathological state,  On the other hand, protein restriction is required to manage acute liver failure and end-stage renal disease. 22  Nitrogen Balance  Nitrogen balance studies are used to assess utilization of dietary amino acids for protein synthesis,  NB determines the balance between anabolic and catabolic process.  Accurate assessment of nitrogen output requires;  An accurate diet record to calculate protein intake,  And the measuremant of fecal and urinary nitrogen (with several correction factor) to assess nitrogen outputs. 23   The appropriate estimate of nitrogen excretion can be obtained through measurement of urine urea nitrogen (UUN). 24  Positive vs. Negative Nitrogen Balance  In an adult, a positive NB is associated with general good health,  A positive NB (protein intake>protein loss) is necessary during period of growth and development, and pregnancy,  A negative NB during periods of starvation, in cachexia and in many hypermetabolic disease states should alert the physician to consider corrective nutritional support. 25 26   One gram of protein provides 4 kcal of energy 28  Lipids  Lipids are the most energy-dense of macronutrients, providing 9 kcal/g,  A typical American diet contains 35% to 45% of calories as fat,  American Heart Association recommends that fat consuption should be reduced less than 30% of total caloric intake. 29  Minerals 30  Fiber  Fiber contains plant cell components that cannot be digested by the gut enzymes,  The insoluble fibers cellulose and lignin, are beneficial to colonic function,  High-fiber diet and their phytates bind divalent metals calcium, iron and zinc lowering these metals bioavailability. 31  MALNUTRITION 32  Types of Malnutrition  There are several types of malnutrition;  Protein-energy malnutrition (PEM) caused by the lack of sufficient protein and food (energy, measured as calories),  Micronutrient (vitamin and mineral) deficiency,  Obesity is caused by eating foods in excess of body needs; this result in accumulation of high levels of body fat. 34  Protein Malnutrition-Kwashiorkor  Conditions of severe protein deficiency termed Kwashiorkor,  Occurs in underdeveloped countries when breast-fed infants are transferred to high-carbohydrate diet,  Primarily affects children younger than age 5. 35  Protein-Energy Malnutrition/Marasmus  Severe overall nutritional deficiency in both calories and protein is called marasmus,  Persons with marasmus exhibit classic signs of starvation, including the loss of subcutaneous fat mass and muscle mass (which produce a wasted appearance),  Muscle proteins is catabolized in order to synthesize glucose from amino acids. 36 37  Undernutrition  Individuals who are receiving insufficient nutrients to meet their needs, but not severe PEM,  Approx. 50% of child death in developing countries can be attributed to undernutrition. 38  Micronutrient Deficiency  Micronutrient deficiency can result from a deficiency in one or more vitamins and minerals,  Micronutrient deficiencies can result in blidness, impaired immune function, and increased severity of common infections,  These deficiencies may also decrease intellectual potential, physical growth and adult productivity. 39  Obesity  Obesity is defined by a body mass index (BMI) greater than or equal to 30,0.  Although protein-calorie malnutrition remains a major problem in developing countries, obesity is a growing problem in affluent societies in all countries. 40   BMI, is a measure for For adults over 20 years indicating nutritional old, BMI falls into one of status in adults. It is the following categories defined as a person’s weight in kilograms divided by the square of the person’s height in metres (kg/m2).  For example, an adult who weighs 70 kg and whose height is 1.75 m will have a BMI of 22.9. 70 (kg)/1.752 (m2) = 22.9 BMI 41 https://www.euro.who.int/en/health-topics/disease-prevention/nutrition/a-healthy-lifestyle/body-mass-index-bmi  THERAPEUTIC NUTRITION SUPPORT  In all cases of PEM, undernourishment, or specific nutrient deficiencies, appropriate nutritional intervention is needed to treat malnoutrished patient. 42  Enteral Feeding  Enteral feeding refers to the introduction of nutrients into the stomach through the tube.  A variety of commercial enteral formulas prepared to meet specific circumtances are used to maintain adequate nutrition.  Whenever possible, enteral feeding is preferred to total parenteral nutrition (TPN) for maintain functioning gut. 43  Parenteral Nutrition  Parenteral nutrition (PN) aims to maintain or improve the nutritional status of patients who are unable to obtain the necessary nutrients from normal feeding or from enteral feeding.  Parenteral nutrient solutions are intravenously administrated,  Isotopic lipid emulsions containing 5% or 10% glucose, 5% amino acids, electrolyte and micronutrients supplying up to 2500 kcal in 3 liters. 44  BIOCHEMICAL PARAMETERS USED TO MONITOR NUTRITIONAL STATUS 45  General Detection & Monitoring of PEM  Assesment of the nutritional status of hospitalized (and nursing home) patient involve in both;  Antropometric measurement  Physical examination  Laboratory measurement 46  Lab. Tests 47  Urinary urea nitrogen (UUN)  Nitrogen balance can be estimated by comparing calculated dietary nitrogen intake with the 24-hour urinary urea nitrogen excretion (UUN).  Urinary urea nitrogen (UUN) is used as an estimate of total urinary nitrogen (TUN). 48   UUN is assumed to constitute 80 to 90% of the total nitrogen output; when estimating TUN from UUN; UUN values are multiplied by 1.25 to correct for non-urea nitrogen components. 49  Protein Synthesis  Interpretation of results of plasma albumin and of specific proteins must taken into account the patient’s conditions such as;  Alteration of fluid volume and fluid shifts,  A presence of acuta-phase response including trauma, infection, malignancy etc.  A decrease in plasma transthyretin (prealbumin), transferrin, retinol-binding protein and albumin result from (at least in part) in conditions other than malnutrition. 50   The levels of specific protein with short biological half-lives are useful in monitoring the response to nutritional supplementation.  Although, the effect of protein supplementation is rapidly reflected by the levels of RBP, prealbumin levels are more predicitive of improved status. 51