BDA nutrition and dietetic care process (BDA, 2012)
Anthropometry allows for an assessment of the different component parts of the human body. Body composition refers to the anatomical makeup of the body in terms of bone, muscle, water and fat. A single measure will not provide a comprehensive overview of the patients’ condition and so a number of measurements are required to form a more reasoned assessment. In malnutrition, changes in body composition lead to Introduction to Malnutrition.
Anthropometric measurements that can be used to assess body composition.
|Measurement||Equation/ method||Interpretation of results|
|Weight and % weight change||% weight change = (current weight - previous weight/ current weight) x 100||
A patient is indicated for nutrition support if they have:
|Body mass index (BMI)||BMI (kg/m2) = weight (kg) / height 2 (m2)||
|Mid upper arm circumference (MUAC)||Involves measuring the circumference of the mid-point on upper arm using a tape measure. This is a surrogate measure of both fat mass and fat free mass. It is a useful measure when a person cannot be weighed or if their weight is not likely to be a true reflection of the persons’ actual weight, e.g. if the patient has oedema or ascites.||
|Skin fold thickness||Measurement requires a trained person using skin fold callipers which have been calibrated. Skin fold measurements can be taken at 4 different sites: suprailliac, subscapular, biceps, triceps (TSF; most commonly used). Measurement should be repeated 3 times and the mean result recorded. This is a surrogate measure of total fat mass. Longitudinal measurements can be used to identify any changes in fat mass.||Centile tables can be used to interpret skin fold thickness measurements.|
|Mid arm muscle circumference (MAMC)||
MAMC is a surrogate measure of fat free mass and is calculated using MUAC and TSF.
MAMC (cm) = MUAC (cm) – 3.14 x TSF (cm)
|Centile tables allow assessment of changes in total body muscle mass over time.|
Other visual signs may indicate recent weight loss such as loose jewellery, baggy clothes, extra notch in belt, ill-fitting dentures, loose or thin looking skin, and prominent bony features.
The blood tests conducted within a nutrition assessment are interpreted in conjunction with a clinical examination; previous medical history; and current medications. Biochemistry tests measure levels of chemical substances present in the blood. Functional tests measure the function of vital organs such as the kidneys or liver.
|Measurement||Rationale||Normal range (note that different laboratories may use different reference ranges)|
|Haemoglobin (Hb)||Assess for iron status or indicate anaemia.||
Women = 12.0 to 15.5 g/dl
Men = 13.5 to 17.5 g/dl
|Albumin (Alb)||A low level may indicate inflammation or infection is present, therefore should not be used to determine nutritional status.||35 - 50 g/L (3.5 - 5.0 g/dL)|
|C-Reactive Protein (CRP)||This is an inflammatory marker which is raised when infection or inflammation is present.||Ideally <10 mg/L|
|White cell count (WCC)||Immune system marker; is raised if infection is present.||4-11 x109/L (4000-11,000 per cubic millimetre of blood)|
|Glycated Haemoglobin (HbA1c)||Indicates an average blood sugar level over a period of months.||Ideally <48 mmol/mol or <6.5% (Diabetes UK)|
|Sodium (Na)||This is an indication of hydration status and kidney function. A raised sodium level may indicate dehydration.||135-145 mmol/L|
|Urea (Ur)||Used to assess kidney function. High urea and other markers levels in combination may indicate dehydration.||2.5-7.1 mmol/L|
|Calcium and Phosphate||Used as a baseline when assessing risk of refeeding syndrome Calcium is adjusted for albumin level||
Adjusted Ca 2.0-2.6 mmol/l
Phosphate 0.7-1.4 mmol/l
|Magnesium||Likely to be low if there are large GI losses||0.7-1.0 mmol/l|
|Micronutrients||Include vitamins and trace elements. These are affected by the acute phase response if inflammation or infection is present and so best measured when CRP is low|
A person’s disease state may increase the risk of malnutrition due to increased energy requirements; reduced energy intake; or increased nutritional losses. Examples of diseases/conditions where this may occur include:
- Chronic Obstructive Pulmonary Disease
- Heart failure
- Gastrointestinal disorders such as Crohns disease, liver disease, coeliac disease
- Neurological conditions such as stroke, Motor Neurone Disease, Parkinsons Disease, multiple sclerosis, dementia
- Burns, surgery or trauma
- Mental health conditions (such as depression)
Symptoms that may impact on a person’s nutritional status either through reducing nutritional intake or increasing nutritional losses include:
- altered bowel movements e.g. diarrhoea, constipation
- upper gastrointestinal upset e.g. reflux, bloating, nausea, and vomiting.
- early satiety
- Estimate Basal Metabolic Rate (BMR) using Henry Equations (2005) based on age, gender and weight (Henry, 2005) or estimate requirements for stable patients using 25-35kcal/kg (NICE 2006).
- Add factor when patient is metabolically stressed
- Add factor for activity and diet induced thermogenesis
- If aiming for weight gain, add 400-600 kcal/day. Only add this for patients who are metabolically stable (i.e. not acutely unwell).
- There are a number of alternative methods to calculate energy requirements in patients who are obese, with care required not to over-estimate requirements.
(Weekes and Soulsby, 2011)
Aged >60 years = 30ml/kg body weight
Aged <60 years = 35ml/kg body weight (Todorovic and Micklewright, 2011)
An estimation of the total daily calorie intake, as well as overall quality of diet should be assessed. Asking the patient (or their family/carer if patient unable) about their daily dietary intake will help understand patterns of eating, portion sizes, cooking methods and types of food and drink taken. Consider asking the following questions to help form a better understanding of the patients’ overall diet:
- What is the patients’ typical food and fluid intake? This can be recorded using food record charts; 24-hour recall; 3-day food diary; or typical day diet history.
- Is the patient eating 3 meals a day?
- Do they have pudding after at least one meal per day?
- Are they eating snacks in between meals?
- Are they eating smaller meals than they used to when they were feeling well?
- Are they having regular drinks, at least 6-8 glasses of fluid/ day?
- Are they having nutritious drinks such as milky tea/coffee, fruit juice, milky drinks?
- Are they having carbohydrate foods (bread, potatoes, pasta, rice, breakfast cereals etc) and protein foods (meat, cheese, beans, egg, fish, milk, yoghurt, cream) at each meal time? Portion sizes should be at least the size of the patient’s fist and amount to 1/3 each on the plate (carbohydrate, protein, vegetables).
- Are they eating at least one portion of fruit or vegetable each day?
- If food is being blended, are they adding nutritious liquids such as milk, cream or gravy to aid blending, rather than water?
- Are they able to cook for themselves?
- Do they have access to essentials such as bread, milk and cheese on a daily basis?
- Do they have a hot/cooked meal each day?
- Are they taking any nutritional supplements? Do they take them as recommended? Do they like them?
|Ability to shop, cook, assistance with eating and drinking, mobility, budget restraints, limited storage facilities, meal timings, family support.||Appetite, dentures, dexterity, use of cutlery, sight, taste changes, nausea, vomiting, heart burn, bloating, early satiety, diarrhoea, constipation, pain, breathing difficulties, dysphagia (swallowing problems), food intolerances, special diets, diminished thirst, taste preferences.|