Nutritional Assessment Lecture KING SALMAN INTERNATIONAL UNIVERSITY PDF

Field of Nursing Community health nursing Lecture : (Nutritional assessment ) Dr : (Afaf hussein ) Date : 21 / 10 /2024  Learning Objectives:  By the end of this lecture the student should be able to: To know the different methods for assessing the nutritional...

Field of Nursing Community health nursing Lecture : (Nutritional assessment ) Dr : (Afaf hussein ) Date : 21 / 10 /2024  Learning Objectives:  By the end of this lecture the student should be able to: To know the different methods for assessing the nutritional status To understand the basic anthropometric techniques, applications, & reference standards INTRODUCTION The nutritional status of an individual is often the result of many inter-related factors. It is influenced by food intake, quantity & quality, & physical health. The spectrum of nutritional status spread from obesity to severe malnutrition Definition of nutritional assessment Nutritional assessment is the systematic process of collecting and interpreting information in order to make decisions about the nature and cause of nutrition related health issues that affect an individual The purpose of nutritional assessment is to: Identify individuals or population groups at risk of becoming malnourished Identify individuals or population groups who are malnourished Nutritional Assessment Why? To develop health care programs that meet the community needs which are defined by the assessment To measure the effectiveness of the nutritional programs & intervention once initiated Methods of Nutritional Assessment Nutrition is assessed by two types of methods; direct and indirect. The direct methods deal with the individual and measure objective criteria, while indirect methods use community health indices that reflects nutritional influences. Direct Methods of Nutritional Assessment These are summarized as ABCD Anthropometric methods Biochemical, laboratory methods Clinical methods Dietary evaluation methods  Indirect Methods of Nutritional Assessment These include three categories: Ecological variables including crop production Economic factors e.g. per capita income, population density & social habits Vital health statistics particularly infant & under 5 mortality & fertility index  Anthropometric Methods Anthropometry is the measurement of body height, weight & proportions. It is an essential component of clinical examination of infants, children & pregnant women. It is used to evaluate both under & over nutrition. The measured values reflects the current nutritional status & don’t differentiate between acute & chronic changes. Anthropometric Measurements Height Weight BMI Mid-arm circumference Skin fold thickness Head circumference Head/chest ratio Hip/waist ratio Anthropometry for children Accurate measurement of height and weight is essential. The results can then be used to evaluate the physical growth of the child. For growth monitoring the data are plotted on growth charts over a period of time that is enough to calculate growth rate, which can then be compared to international standards Growth Monitoring Chart Percentile chart  Measurements for adults Height: The subject stands erect & bare footed on a stadio meter with a movable head part. Shoes must be removed Heels, buttocks, shoulders and back of head should be touching the wall. The head part is leveled with skull vault & height is recorded to the nearest 0.5 cm. Weight measurement Use a regularly calibrated electronic or balanced-beam scale. Weight in light clothes, no shoes Read to the nearest 100 gm (0.1kg)  Nutritional Indices in Adults The international standard for assessing body size in adults is the body mass index (BMI). BMI is computed using the following formula: BMI = Weight (kg)/ Height (m²) Evidence shows that high BMI (obesity level) is associated with type 2 diabetes & high risk of cardiovascular morbidity & mortality BMI (WHO - Classification) BMI < 18.5 = Under Weight BMI 18.5-24.5= Healthy weight range BMI 25-30 = Overweight (grade 1 obesity) BMI >30-40 = Obese (grade 2 obesity) BMI >40 =Very obese (morbid or grade 3 obesity) Skin fold thickness Skin fold thickness is an indirect measure of subcutaneous adipose tissue using skin fold calipers at various body sites. Body density and percentage body fat can then be estimated based on these measurements.  Perform measurements on the left side of the body Use a flexible tape Mark the site to be measured between the acromion processes of scapula and olecranon processes at elbow , with the arm held freely to the side of the body Firmly grasp the skin fold and Place caliper 1 cm from the thumb and finger (pinch), perpendicular to the skin fold, halfway between the crest and base of the fold. Maintain pinch while reading the caliper Wait no longer than 1-2 seconds before reading the caliper Retest measurements if they are not within 1-2 mm. Mid arm circumference (MAC) The subject left arm should be bent to elbow at a 90 degree angle with the upper arm held parallel to the side of the body.Measure the distance between the bony protrusion on the shoulder (acromion) and the point of the elbow (olecranon process) Ask the subject to jet arm hang loose and measure around the upper arm at the mid-point making sure that the tape measure is comfortable but not tight. Mid-arm muscle circumference and mid-upper-arm muscle area Mid-arm muscle circumference (MAMC) has been used for reflection of muscle protein reserves. This is performed in addition to triceps skin fold measurement to calculate mid-upper-arm muscle area, which correlates with lean body mass.  Obtaining the MAMC requires that the upper-arm length first be measured and the halfway point determined, marking this location for measuring circumference. The subject should stand with weight distributed evenly on both feet and right arm bent 90°. Arm length is measured from the most superior point on the scapular spine to the tip of the olecranon process on the posterior aspect of the arm  Circumference measurement is performed with a measuring tape positioned perpendicular to the length of the arm, at the marked location. Triceps skin fold should be performed at this location also. Once arm circumference and skin fold measurements are complete, the results can be used to calculate mid-upper- arm muscle area Calculation of MAMC Triceps Skin - fold (TSF) mm Mid – Arm circumference (MAC) Cm Mid – Arm Muscle circumference (MAC) Cm MAMC (cm) = MAC (cm) - (3.14 × TSF/10 (cm)= The TSF is measures in mm. You will need to convert the TSF from mm to cm in order to calculate MAMC.  Waist/Hip Ratio Waist circumference is measured at the level of the umbilicus to the nearest 0.5 cm. The subject stands erect with relaxed abdominal muscles, arms at the side, and feet together. The measurement should be taken at the end of a normal expiration.  Waist circumference Waist circumference predicts mortality better than any other anthropometric measurement. It has been proposed that waist measurement alone can be used to assess obesity, and two levels of risk have been identified MALES FEMALE LEVEL 1 > 94cm > 80cm LEVEL2 > 102cm > 88cm Waist circumference Level 1 is the maximum acceptable waist circumference irrespective of the adult age and there should be no further weight gain. Level 2 denotes obesity and requires weight management to reduce the risk of type 2 diabetes & CVS complications. advantages of anthropometry Objective with high specificity & sensitivity Measures many variables of nutritional significance (Ht, Wt, MAC, HC, skin fold thickness, waist & hip ratio & BMI). Readings are numerical & gradable on standard growth charts Readings are reproducible. Non-expensive & need minimal training Limitations of Anthropometry Inter-observers errors in measurement Limited nutritional diagnosis Problems with reference standards, i.e. local versus international standards. Arbitrary statistical cut-off levels for what considered as abnormal values. Biochemical Method Initial Laboratory Assessment 1- Haemoglobin estimation Most important test when accurately measured, tells about overall state of nutrition (anemia, and also protein and trace element nutrition) Blood is collected from a finger, ear lobe or heel prick Haemoglobinometres which are simple, cheap and reasonably accurate are used 2. Haematocrit or packed cell volume (PCV) percentage of the blood volume composed of red cells. important in the diagnosis of anemia. 3. Red cell counts and blood films the size and uniformity of the red blood cells can be seen. Use of such slides may facilitate the diagnosis of malaria and the haemoglobinopathies. Parasites if present can be seen.  4. Stool examination For presence of ova and/ or intestinal parasites When assessed quantitatively parasite load can be known 5. Urine examination Dipstick and microscopy for albumin, sugar and blood Specific Lab Tests Measurement of individual nutrient in body fluids (e.g. serum retinol “Vit A”, serum iron, urinary iodine, vitamin D) Detection of abnormal amount of metabolites in the urine (e.g. urinary creatinine) Analysis of hair, nails & skin for micro-nutrients. Advantages of Biochemical Method It is useful in detecting early changes in body metabolism & nutrition before the appearance of overt clinical signs. It is precise and accurate Useful to validate data obtained from dietary methods e.g. comparing salt intake with 24-hour urinary excretion. Limitations of Biochemical Method Time consuming Expensive They cannot be applied on large scale Needs trained personnel & facilities  Clinical assessment It is an essential features of all nutritional surveys It is the simplest & most practical method of ascertaining the nutritional status of a group of individuals It utilizes a number of physical signs, (specific & non specific), that are known to be associated with malnutrition and deficiency of vitamins & micronutrients. Clinical assessment Good nutritional history should be obtained General clinical examination, with special attention to organs like hair, angles of the mouth, gums, nails, skin, eyes, tongue, muscles, bones, & thyroid gland. Detection of relevant signs helps in establishing the nutritional diagnosis Clinical assessment ADVANTAGES Fast & Easy to perform Inexpensive Non-invasive LIMITATIONS Did not detect early cases Dietary assessment Nutritional intake of humans is assessed by five different methods. These are: 24 hours dietary recall Food frequency questionnaire Dietary history since early life Food dairy technique Observed food consumption 24 Hours Dietary Recall A trained interviewer asks the subject to recall all food & drink taken in the previous 24 hours. It is quick, easy, & depends on short-term memory, but may not be truly representative of the person’s usual intake Food Frequency Questionnaire In this method the subject is given a list of around 100 food items to indicate his or her intake (frequency & quantity) per day, per week & per month. inexpensive, more representative & easy to use.  Food Frequency Questionnaire Limitations:  long Questionnaire  Errors with estimating serving size.  Needs updating with new commercial food products to keep pace with changing dietary habits. Dietary history It is an accurate method for assessing the nutritional status. The information should be collected by a trained interviewer. Details about usual intake, types, amount, frequency & timing needs to be obtained. Cross-checking to verify data is important. Food dairy Food intake (types & amounts) should be recorded by the subject at the time of consumption. The length of the collection period range between 1-7 days. Reliable but difficult to maintain.  Observed Food Consumption The most unused method in clinical practice, but it is recommended for research purposes. The meal eaten by the individual is weighted and contents are exactly calculated. The method is characterized by having a high degree of accuracy but expensive & needs time & efforts.