Nutrition IV Lec 5 PDF

NUTRITION IV Nikita Sahadeo, Ph.D. Biochemistry Unit Department Of Preclinical Sciences Faculty of Medical Sciences University of the West Indies January 2024 LEARNING OBJECTIVE Describe the assessment of nutritional status in children, adolescents, and adults MALNUTRITION Malnutrition refers to all...

NUTRITION IV Nikita Sahadeo, Ph.D. Biochemistry Unit Department Of Preclinical Sciences Faculty of Medical Sciences University of the West Indies January 2024 LEARNING OBJECTIVE Describe the assessment of nutritional status in children, adolescents, and adults MALNUTRITION Malnutrition refers to all deviations from adequate nutrition, including undernutrition (and overnutrition) resulting from inadequacy of food (or excess of food) relative to need (respectively). Malnutrition also encompasses specific deficiencies (or excesses) of essential nutrients such as vitamins and minerals. Conditions such as obesity, although not the result of inadequacy of food, also constitute malnutrition. The terms "malnutrition" and "undernutrition" are often used loosely and interchangeably, although a distinction is, and needs to be, made at all times. "Malnutrition" arises from deficiencies of specific nutrients or from diets based on wrong kinds or proportions of foods. Goitre, scurvy, anaemia and xerophthalmia are forms of malnutrition caused by inadequate intake of iodine, vitamin C, iron and vitamin A respectively. UNDERNUTRITION "Undernutrition" is the outcome of insufficient food of whatever kind caused primarily by an inadequate intake of dietary or food energy, whether or not any specific nutrient deficiency, such as iron deficiency anaemia, is present. Undernutrition is defined as a dietary energy intake below the minimum requirement level to maintain the balance between actual energy intake and acceptable levels of energy expenditure. This must take into account additional needs for growth in children and also for pregnant and lactating women to maintain appropriate weight gain associated with adequate foetal growth in pregnancy and to sustain sufficient milk production during lactation (FAO/WHO/UNU, 1985). UNDERNOURISHMENT "Undernourishment" is when food intake is continuously insufficient to meet the dietary energy requirements, while undernutrition is the result or outcome of undernourishment, poor absorption and/or poor biological use of nutrients consumed (FAO, 1999). ASSESSMENT OF UNDERNUTRITION Nutritional intake assessment Estimates the amount of food a person is eating and can be used to assess adequacy of the quantity of dietary energy (and protein) supply. In simple terms, one can categorize people as being well -nourished or undernourished based on whether their intake of food matches their food energy needs or nutrient requirements. Nutritional status assessment Assesses the nutritional status of the individual or a representative sample of individuals within a population by measuring anthropometric, biochemical or physiological (functional) characteristics to determine whether the individual is well-nourished or undernourished. This method makes use of objective, measurable criteria that reflect the changes in anthropometric, biochemical or functional characteristics of the individual as a consequence of inadequate intakes of food for long periods of time, or as a result of seasonal fluctuations in intakes of food or poor absorption and utilization of ingested food. A hierarchical model of the causes of undernutrition emphasizes the importance of repeated infectious episodes and poor care and neglect as determinants of undernutrition, in addition to the lack of adequate food (UNICEF, 1998). Anthropometry is the most frequently used method to assess the nutritional status of individuals or population groups. Measurements of nutritional anthropometry are based on growth in children and body weight changes in adults. NUTRITIONAL STATUS ASSESSMENT Benefits: immediate treatment; development of healthcare programmes to meet community needs; assessment of effectiveness of programmes Methods of nutritional assessment: direct methods; indirect methods. INDIRECT METHODS Use community health indices that reflects nutritional influences These include: ecological variables including crop production; economic factors e.g. per capita income, population; density and social habits; vital health statistics particularly infant under 5 mortality and fertility index. DIRECT METHODS Deal with the individual and measure objective criteria Summarised as ABCD: A. Anthropometric methods; B. Biochemical methods; C. Clinical methods; D. Dietary evaluation methods. ANTHROPOMETRIC MEASUREMENTS Defined as "measurements of the variations of the physical dimensions and the gross composition of the human body at different age levels and degrees of nutrition ” Of two types: growth and body composition, and have been widely used for the assessment of the nutritional status of both children and adults The measurement of body weight and proportions An essential part of clinical examination of infants, children, and pregnant women Evaluates both malnutrition and nutritional excesses Assesses current nutritional state ANTHROPOMETRIC MEASUREMENTS 1. Height/age ratio and weight/height 2.Mid-upper arm circumference 3. Head circumference 4. Skin fold thickness 5. BMI 6. Waist/hip ratio ADVANTAGES OF NUTRITIONAL ANTHROPOMETRY Methods are precise and accurate, provided standardized techniques are used Procedures use simple, safe and non-invasive techniques Equipment required is inexpensive, portable and durable, and can be made or purchased locally Relatively unskilled personnel can perform measurement procedures Information is generated on past nutritional history Methods can be used to quantify the degree of undernutrition (or overnutrition) and provide a continuum of assessment from under-to overnutrition Methods are suitable for large sample sizes such as representative population samples Methods can be used to monitor and evaluate changes in nutritional status over time, seasons, generations, etc. Methods can be adopted to develop screening tests in situations such as nutrition emergencies to identify those at high risk LIMITATIONS OF NUTRITIONAL ANTHROPOMETRY The relative insensitivity to detect changes in nutritional status following inadequacy of food over short periods of time The inability to distinguish the effect of specific nutrient deficiencies (e.g. zinc deficiency) that affect growth in children from that due to inadequacy of food in general The inability to pinpoint the principal causality of undernutrition, as the poor nutritional status may be the result of factors such as repeated insults owing to infections and poor care in children The relative higher costs and organization required to obtain representative and quality data for the purpose of estimating numbers of undernourished HEIGHT/AGE RATIO Accurate measurement of height and weight is necessary to evaluate the proper growth of a child Ht/Age: appropriate height for given age. Wt/Ht: appropriate weight for given height. MID UPPER ARM CIRCUMFERENCE Measured half-way between the acromion process of the scapula and the tip of the elbow (ulnar) with the arm hanging vertically and forearm supinated Provides estimate of arm muscle area: reflects skeletal protein reserves. HEAD CIRCUMFERENCE The measurement of the head along the supra orbital ridge (forehead) anteriorly and occipital prominence (the prominent area on the back part of the head) posteriorly. It is measured to the nearest millimetre using flexible, nonstretchable measuring tape around 0.6cm wide. Useful in assessing chronic nutritional problems in children under two years old as the brain grows faster during the first two years of life. But after two years the growth of the brain is more sluggish and HC is not useful. Malnutrition will have to be severe to affect head circumference SKIN FOLD A skinfold caliper is used to assess the skinfold thickness, so that a prediction of the total amount of body fat can be made.This method is based on the hypothesis that the body fat is equally distributed over the body and that the thickness of the skinfold is a measure for subcutaneous fat. To estimate the total amount of body fat, four skinfolds are measured: 1. Biceps skinfold (front side middle upperarm) 2. Triceps skinfold (back side middle upperarm) 3. Subscapular skinfold (under the lowest point of the shoulder blade) 4. Suprailiac skinfold (above the upper bone of the hip) For this measurement the patient must be able to sit or stand in an upright position. Skinfold measurements are cheap, not very painful and easy to perform, although practice is required. With the table of Durnin en Womersly (1974), the percentage of body fat can be read by a given age and sex. THE TRICEPS SKIN FOLD The most reliable one to assess, because oedema is not often seen in the upper arm. Measurements are less reliable in elderly people, due to their weak skin and muscles. As a result, their muscles are often taken in the skinfold. Also in patients with chronic muscle diseases, dehydration and oedema, skinfold measurements can give unreliable values. Measurements should be performed by a trained person; the accuracy of the measurements largely depend on the way they are done. The triceps skinfold is necessary for calculating the upper arm muscle circumference. Its thickness gives information about the fat reserves of the body, whereas the calculated muscle mass gives information about the protein reserves. Better to repeat the measurements for a good indication of changes in nutritional status and body fat mass. BODY MASS INDEX (BMI) Formerly called the Quetelet index A measure for indicating nutritional status in adults. It is 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) The BMI ranges are based on the effect excessive body fat has on disease and death and are reasonably well related to adiposity. Developed as a risk indicator of disease; as BMI increases, so does the risk for some diseases. Some common conditions related to overweight and obesity include: premature death, cardiovascular diseases, high blood pressure, osteoarthritis, some cancers and diabetes. BMI is also recommended for use in children and adolescents. In children, BMI is calculated as for adults and then compared with z-scores or percentiles. During childhood and adolescence the ratio between weight and height varies with sex and age, so the cut-off values that determine the nutritional status of those aged 0–19 years are gender- and age-specific. WAIST/HIP RATIO The waist-to-hip ratio (WHR) is a quick measure of fat distribution that may help indicate a person’s overall health. People who carry more weight around their middle than their hips may be at a higher risk of developing certain health conditions. According to the World Health Organization (WHO), having a WHR of over 1.0 may increase the risk of developing conditions that relate to being overweight, including heart disease and type 2 diabetes. This may be the case even if other measures of being overweight, such as body mass index (BMI) are in normal range. The WHO advise that a healthy WHR is: 0.85 or less for women 0.9 or less for men Visceral Fat (VF) is the underlying culprit for cardiovascular diseases, type 2 diabetes, breast cancer, etc.VF can be estimated at present only by using expensive instruments as Bio Impedance Analyzer (BIA), DEXA scanner, etc. Measurement of Waist-Hip Ratio (WHR) can be used as a proxy for VF. BIOCHEMICAL METHODS Biochemical or laboratory methods of assessment include measuring a nutrient or its metabolite in the blood, faeces, urine or other tissues that have a relationship with the nutrient. The levels of nutrients and their metabolites in body tissues and fluids as these area consequence of the variations in quantity and nutrient composition of food consumed and utilized by the body. Biochemical tests are sensitive to even small changes in nutritional intake and therefore, provide the earliest indication to malnutrition. Biochemical assessment also confirms clinical diagnosis of nutritional status and/ or risk for a disease. There are several biochemical tests that can be done on bones, hair, nails, subcutaneous fat, liver etc., however, in community settings most commonly, these tests are conducted on blood, urine and stool samples. Commonly used tests: Haemoglobin – gives a useful indication of the overall state of nutrition HbA1c Glycation test – gives average blood glucose levels over the past 3 to 4 months Urine analysis (for albumin and sugar) Blood levels of lipoproteins and triglycerides BIOCHEMICAL METHODS Advantages: able to detect early changes in body metabolism and nutrition before the appearance of clinical signs; accurate and reproducible; useful to validate data obtained from dietary methods (e.g. comparing salt intake with 24hour urinary excretion. Disadvantages: expensive; time consuming; needs trained personnel and facilities. CLINICAL METHODS Assess clinical signs and symptoms that might indicate potential specific nutrient deficiency Special attention are given to organs such as skin, eyes, tongue, ears, mouth, hair, nails, and gums Clinical methods of assessing nutritional status involve checking signs of deficiency at specific places on the body or asking the patient whether they have any symptoms that might suggest nutrient deficiency Advantages: fast and easy to perform; inexpensive; non-invasive. Limitations: may not detect early stages malnutrition. SEVERE DIETARY DEFICIENCIES If dietary deficiencies are persistent, children stop growing: low height for age; chronic malnutrition. If child experience weight loss or wasting: low weight for height; acute malnutrition. Both chronic and acute malnutrition may be further classified as moderate or severe SEVERE ACUTE MALNUTRITION Case fatality rate up to 21% without effective intervention Includes two main clinical forms: severe wasting (marasmus); nutritional edema (kwashiorkor). Clinical analysis determines if treatment will be in hospital or with therapeutic ready-to-use-foods (RUFs) at home Most children given therapeutic RUF treatment at home PROTEIN-CALORIE MALNUTRITION Protein-calorie malnutrition reflects starvation or specific deficiencies A deficiency of proteins in diets relatively high in carbohydrates leads to kwashiorkor A deficiency of all components of a diet leads to marasmus 4 to 5 million children younger than 5 die every year from malnutrition MARASMUS VS. KWASHIOKOR MARASMUS KWASHIOKOR severe weight loss and wasting; Derived from a term that means "the disease that occurs when the next baby is born" subnormal body temperature; Characterised by: decreased pulse and metabolic rate; edema; loss of skin turgor; low capillary-filtration rate; Characterised by: constipation; starvation diarrhea (consisting of frequent, small, mucus-containing stools). hypoalbuminemia; dermatitis. DIETARY EVALUATION METHODS Several methods of dietary assessment are available and the same methods can be categorized in more than one of the following ways, such as: Qualitative and quantitative methods Retrospective and prospective methods Family and Individual inquiry methods Qualitative methods usually give information about food related behaviour. For example, food frequency questionnaires are used mainly for determining the frequency of consumption of different foods. Whereas, quantitative methods such as 24-hour diet recall is used to determine the amounts of different foods consumed in the previous 24 hours. Retrospective methods such as 24-hour diet recall, diet history, food frequency questionnaire collect information about dietary intake in the past (generally the previous day) while prospective methods such as food records, weighment method, duplicate portion (chemical analysis) method collect information about current food intake of the day when the information is being gathered. DIETARY EVALUATION METHODS Inventory and Food list methods give information about the food intake of families, households or a group and methods like 24-hour diet recall, diet history, food frequency questionnaire, food records, chemical analysis of duplicate portion method etc. are used for dietary assessment of individuals. Of the several methods of dietary assessment that are available, the most commonly used ones are the 24-hour recall method, Food Record method and the Food Frequency Questionnaire (FFQ) method. 24 HOUR DIET RECALL METHOD Advantages: It is inexpensive and quick to administer. It requires only short-term memory as the food eaten only on the previous day has to be recalled. It is well accepted by individuals as they are not required to keep a record of food consumed; and their expenditure of time and effort is also relatively low. It is useful for assessing average usual intakes of a large population. There is an element of surprise in this method and the individuals are therefore, less likely to deliberately modify their eating patterns. Limitations: As the method relies on memory, it may not be suitable for elderly. Unless properly probed by the investigator, individuals may withhold or alter information about their food intake due to embarrassment or to impress the investigator. This method usually gives estimates of dietary intake rather than the actual intake. FRM & FFQ Food Record method – This method is similar to the 24 hour recall method in the manner food consumption information of individuals is noted. However, the major difference is that the information here is noted by the individual himself as and when the food is being consumed, unlike the 24 hour recall method where the information is noted by the investigator for a previous day’s consumption of the individual. The individuals may note the intake in terms of household measures or may actually weigh the amount of food consumed.The information using this method may be recorded for a period of 1 – 7 days. This method is also sometimes referred to as the Diary method. An advantage of this method is that it does not depend much on memory as the individuals record the information simultaneously at the time of consumption. However, this method can be used only for individuals who are literate and can record the intake themselves. Food Frequency Questionnaire (FFQ): This method involves asking individuals how often or how many times (daily, weekly, monthly, etc.) they have consumed specific foods. The information may be recorded through interview or a self-administered questionnaire. The FFQ consists of two components – a food list and a frequency response section for individuals, as shown in the template. In the food list, the foods are usually grouped into categories based on the similarity of nutritive value, functions in the diet etc. This method provides only qualitative information such as food consumption pattern, dietary habits, food preferences of individuals etc. This method can be used to get an idea about specific nutrient deficiencies in an individual if the food list contains items which are mainly good sources of a particular nutrient. For example, to get an idea about vitamin A deficiency in the individual, the food list should mainly contain foods sources of vitamin A and the individual’s frequency of consumption of those items will indicate whether he is likely to have vitamin A deficiency. This method, however, can only give some indications which need to be confirmed using other more specific and accurate methods.