Nutritional Assessment

Dr. ahmad salahuddin

Nutritional assessment is an extremely useful tool for

the application of nutritional therapy.

It includes both the screening and assessment of the

person’s nutritional status.

It is related to the individual’s

(1) food and nutrient intake (diet history),

(2) lifestyle,

(3) medication intake,

(4) social and medical history

(5) anthropometric, body composition and biochemical measurements.

Dietary history:

•This dietary history should provide all the data needed

in order to evaluate the food and fluid intake.

Some of the most frequent and necessary information

collected is:

• the usual dietary and meal plan, the number of meals,

the usual meal size and the common amount of food,

the usual location of eating,

• the consumption of ready-made meals, snacks and fast

food,

• fluid intake, including the consumption of beverages

and alcohol,

•possible food allergies, food preferences and the

frequency of consumption.

Body mass index BMI:•BMI is the most recommended classification of body weight and one of the simplest and most widely used methods for the estimation of body fat.

BMI = Weight (kg) / Height (m2)

•BMI is an indicator of the stores of body fat, being related to an increased danger of illness and mortality.

Classification of weight status by body mass index.

•Persons with a BMI <18.5 have an increased mortality rate.

•BMI is not directly correlated with the accumulation of body fat, and for this reason there are exceptions (e.g. athletes, who have a very limited level of body fat and cannot be classified as overweight or obese like other adults).

Anthropometric:

•The term ‘anthropometric’ refers to comparative

measurements of the body, which are used in

nutritional assessments in order to understand human

physical variation.

The anthropometric measurements which are used for infants, children and adolescents usually include:•Length,•Height,•Weight,•Weight-for-length,•Head circumference (length is used in infants and toddlers, rather than height, because they are unable to stand).

•The anthropometric measurements which are used for adults usually include:•Height,•Weight,•BMI,•Waist/hip ratio,•Percentage of body fat.

•The waist/hip ratio (WHR) is the ratio of the

circumference of the waist to that of the hips and is

calculated by measuring the waist circumference, just

above the upper hip bone and dividing by the hip

circumference at its widest part.

•WHR of 0.9 for men and 0.7 for women has been shown to correlate strongly with a general status of healthy, •WHR over 1.0 for men and over 0.8 for women are indicative of the presence of central obesity and increased risk of related diseases (associated with higher risk of diabetes and hypertension). •WHR above 0.95 for men or 0.8 for women indicate a heightened risk of heart attack.

Biochemical markers for nutritional evaluation:•Serum albumin: The serum albumin level is an indicative marker, for the nutritional evaluation of a patient, although it has a relatively long half-life of 21 days.

Patients with low serum albumin levels are in poor nutritional condition and at high risk of death.

•Pre-albumin: Malnourished patients have significantly lower levels of pre-albumin.

•Serum creatinine: it is used as a nutritional marker, because of its relation to muscle mass. Measuring serum creatinine is a simple test and it is the most commonly used indicator of renal function.

•Serum transferrin: This is an iron-transport protein, which serves as a sensitive marker of total nutrition status and more specifically as a marker of iron deficiency.

Dehydration:Dehydration is a fluid imbalance caused by inadequate intake or excessive losses.

There are different biochemical markers that can identify and reveal the presence of dehydration.

These markers are:

•Urea/creatinine ratio, which should be ≥0.15

•Elevated levels of plasma sodium

•Urine colour or specific urine gravity

•Serum osmolarity.

• It is recommended that the fluid intake should be at

least 500–750 ml greater than urinary losses, but it

should be even greater in cases of high temperatures or

the presence of burn or pyrexia or in the case of any

other reason of higher-than-normal losses.

•Dehydration is linked with constipation, medication

toxicity, renal failure, urinary tract infections, elevated

body temperature, dizziness and general weakness.

Malnutrition

•Malnutrition: is a general term for a medical condition

caused by an improper or insufficient diet.

•The term usually refers to generally bad or faulty

nutrition and is most often related to undernutrition.

•Malnutrition is the ‘cellular imbalance between supply of

nutrients and energy and the body’s demand for them to

ensure growth, maintenance and specific functions’,

• it is the greatest risk factor for illness and death worldwide.

• It can be associated with both undernutrition and

overnutrition.

Causes of malnutrition:

• The most common causes of malnutrition worldwide

are Anorexia, inadequate food intake or lack of food

supplies and loss of appetite.

• Anorexia can result from pathophysiological,

psychological and general social problems.

•Different types of chronic and inflammatory diseases

can lead to reduced food intake and malnutrition.

•Also, nausea and vomiting and the use of certain drugs

or specific treatments (chemotherapy, radiotherapy)

may have a negative effect on appetite.

Protein and energy malnutrition:The most common physical signs are:•Weight loss and cachexia.

•Decreased subcutaneous tissue and reduction in muscle and body tissue mass, which can be most often observed in the legs, arms, buttocks and face.

•Oedemas.

•Neurological problems and abnormalities.•Oral changes (red and usually swollen mouth, lips and gums).•Muscle cramp and pain.•Skin changes (dry and peeling, frail, swollen, pale, loss of elasticity and poor healing).•Hair changes (dry and discoloured).

Cachexia:•Cachexia is a wasting syndrome, regulated by cytokines, and a condition of general ill health, malnutrition, undesired weight loss and physical weakness. •Cachexia is associated with various chronic and end-stage diseases and medical conditions (e.g. metabolic acidosis, infectious diseases, autoimmune disorders and malignant conditions).

•Cachexia is characterized by changes in fat, protein

and carbohydrate metabolism such as increased

lipolysis, gluconeogenesis and protein turnover,

glucose intolerance and hyperinsulinaemia,

hyperlipidaemia, decreased plasma levels of branched-

chain amino acids.

Kwashiorkor:

Kwashiorkor (from the West African word for ‘displaced child’) is a form of protein and energy malnutrition.

•The main cause of this form of malnutrition is inadequate protein intake and the low concentration of essential amino acids.

•Kwashiorkor is a severe form of undernutrition, which develops in individuals on diets with a low protein/energy ratio.

•The main symptoms of Kwashiorkor are oedema, wasting, liver enlargement, hypoalbuminaemia, steatosis and the possible depigmentation of skin and hair.

Marasmus:

•Marasmus (from the Greek word for ‘to waste away’)

is the other form of malnutrition, which is caused by

the inadequate intake of both protein and energy.

• It is a form of severe cachexia with weight loss as a

result of wasting in infancy and childhood.

•The main symptoms of marasmus are severe wasting,

with little or no oedema, minimal subcutaneous fat,

severe muscle wasting and non-normal serum albumin

levels.

•The main clinical signs of the most common vitamin and mineral deficiencies:

Food Allergy

•Food allergy refers to specific reactions that result from an abnormal immunological response to a food and which can be severe and life-threatening and triggered by minute amounts of the allergen.•Non-allergic food intolerance refers to reactions to food that can result from a number of causes, none of which is mediated by the immune system (e.g. pharmacological effects, enzyme deficiencies, irritant and toxic effects).

Types of food allergy:• immunoglobulin E (IgE) mediated (early onset) and non-IgE mediated (late onset, delayed).

• IgE mediated reactions generally present soon after ingestion and thus easy to investigate and diagnose. They can be more violent than non-IgE mediated reactions and can even lead to death through anaphylaxis in severe cases.

•Early-onset manifestations often include wheezing, urticaria, angioedema, rashes, vomiting and anaphylaxis,

•whereas late-onset symptoms include diarrhoea, abdominal pain, allergic rhinitis, atopic eczema, food-sensitive enteropathy or food-sensitive colitis, protein-losing enteropathy and constipation.

Food that cause allergy:Common foods that can cause an allergic reactions: • peanuts and tree nuts (e.g. hazelnut, Brazil nut, walnut), •milk (cow’s, goat’s, sheep’s), • soya, fish, shellfish, eggs, • seeds (especially sesame and caraway), • fruits (especially apples, peaches, plums, cherries, bananas, citrus fruits), • and herbs and spices (especially mustard, paprika and coriander).

However, the most common allergies, according to the frequency they occur, are:•Children: cow’s milk, egg, soya, peanut, tree nuts, fish and crustaceans•Adults: peanut, tree nuts, crustaceans, fish and egg.The processing of food may also affect its allergenicity. For example, the allergenicity of many fruits may be greatly reduced by cooking, and that of eggs, milk and some fish may be attenuated.

Management:It is essential to ensure that:•All potential sources of the allergen are avoided•The effects of the exclusion diet on the intake of other nutrients and overall dietary balance are minimised.