Clinical Nutrition Session 8: Assessing Nutritional Status of Clients

Learning Objectives

In this session on assessing the nutritional status of clients, students will focus on several key objectives:

  1. Growth Disorders: Understand various growth disorders such as stunting, underweight, wasting, overweight, and obesity.
  2. Methods of Assessment: Learn different methods of assessing nutritional status, including obtaining a client’s dietary history and performing anthropometric measurements.
  3. Indicators: Analyze indicators like weight-for-height/length, weight-for-age, height/length-for-age, and Mid Upper Arm Circumference (MUAC) for nutritional assessment in young children.
  4. Body Mass Index (BMI): Determine how BMI serves as an indicator of nutritional status in older children and adults.
  5. Nutritional Advice: Apply findings to provide appropriate nutritional advice to clients.

Growth Disorders

Stunting
  • Definition: Stunting is characterized by low height-for-age, indicating chronic under-nutrition, often due to prolonged illness or inadequate food intake.
  • Alternative Name: Commonly referred to as ‘short stature’.
Underweight
  • Adults: Defined as having a BMI of less than 18 kg/m².
  • Children: Considered underweight if they weigh 80-60% of the expected normal weight.
Wasting
  • Definition: This condition involves the gradual atrophy of body tissues associated with protein-energy malnutrition or chronic illness. It indicates acute under-nutrition.
  • Indicators: Wasting is characterized by low weight-for-age and weight-for-height despite unchanged height, representing a rapid decline in body weight attributed to inadequate dietary intake or acute infections.
Overweight and Obesity
  • Overweight: An adult is classified as overweight if they have a BMI between 25-29.9 kg/m².
  • Obesity: Defined as a condition having a BMI of 30 kg/m² or above, indicating excessive body fat accumulation.

Methods of Assessing Nutritional Status

Assessment methods are critical for evaluating nutritional health:

  1. Dietary History: Assess the quantity and type of food consumed. This involves interviewing the client or their caretakers for qualitative or quantitative data on food intake.
  2. Anthropometry: Involves measuring physical attributes like height, weight, BMI calculation, and MUAC.
  3. Physical Examination: Identifies outward signs of nutritional deficiencies.
  4. Laboratory Tests: Detect early signs of nutritional imbalances before clinical symptoms manifest.

Dietary History Collection

When gathering dietary history, specific questions should be asked regarding:

  • Types and amounts of food eaten.
  • Eating frequency, preferences, dislikes, taboos, and any existing eating issues such as lack of appetite.
  • Factors impacting food availability and preparation, including hygiene practices and resources for food acquisition.

Anthropometric Measurements

  • Basic Measurements: Include height, weight, BMI, MUAC, and skinfold thickness.
  • Children Assessment: Weight-for-age is essential for tracking the growth and nutritional status of children, particularly those under five years. Measurement requires serial weighing and is often monitored at health clinics. Underweight children are categorized based on their Z-scores:
    • Moderately underweight: < -2 Z-score
    • Severely underweight: < -3 Z-score.

MUAC Measurement

  • Definition: MUAC is specifically measured at the midpoint of the left upper arm and is beneficial in assessing the nutritional status of pregnant women and individuals with edema.
  • Application: Effective as an alternative to weight-for-height measurements, particularly in children ages 1-5 and adults who cannot stand for traditional measures.

Body Mass Index (BMI)

  • Definition: BMI assesses nutritional status in both adults and adolescents, calculating weight relative to height using the formula: BMI=weight (in kg)height (in m)2\text{BMI} = \frac{\text{weight (in kg)}}{\text{height (in m)}^2}.
  • Interpretation: Categories include:
    • Below 16.0: Severe under-nutrition
    • 16.0 - 17.0: Moderate under-nutrition
    • 17.1 - 18.4: Mild under-nutrition
    • 18.5 - 24.9: Good nutritional status
    • 25.0 - 29.9: Overweight
    • 30.0 and above: Obesity.

Physical Exam and Clinical Signs

A physical examination can reveal clinical signs such as:

  • Wasting: Significant loss of body mass.
  • Pallor: May signal anemia due to nutrient deficiencies.
  • Oedema: Indicative of certain macronutrient deficiencies.
  • Specific Vitamin Deficiencies: For instance, vitamin A deficiency may lead to specific ocular signs, while vitamin D can result in rickets.

Laboratory Tests for Nutritional Status

Biochemical Tests

These tests are crucial for detecting early malnutrition. Direct measurements focus on concentrations of nutrients in bodily fluids. For example, hemoglobin levels can indicate nutritional anemia.

  • Haemoglobin Cut Off Points: For different populations:
    • Adult men: < 13.0 g/dL
    • Non-pregnant women: < 12.0 g/dL
    • Pregnant women: < 11.0 g/dL
    • Children: Vary by age, with thresholds set for anemia risk assessment.
Indirect Measurements

Identifying nutrient deficiencies often requires assessing nutrient stores rather than plasma concentrations alone, which can remain normal until severe deficiency occurs. For example:

  • Iron Assessment: Serum ferritin indicates available iron stores.
  • Nutritional Indices: Plasma albumin levels < 30 g/L are frequently used to gauge malnutrition.

Nutritional Advice

Nutritional advice plays an essential role in promoting healthy dietary behaviors and improving the nutritional status of clients. Considerations include:

  • Promoting healthy eating and exercise.
  • Addressing food security and safety.
  • Encouraging lifestyle changes and management of dietary issues related to health conditions (e.g., HIV/AIDS).
  • Ensuring ongoing nutritional monitoring and the continuation of health services during and post-illness.

Key Points

Overall, effective assessment of nutritional status is crucial for identifying malnutrition, which guides healthcare providers in making informed treatment decisions. Accurate assessments lead to tailored nutritional counseling, ensuring clients are provided with appropriate dietary management to meet their health needs.

References

  • MoHSW. (2008). National Guidelines for the Management of Acute Malnutrition. Ministry of Health and Social Welfare.
  • Stanfield, P. & Bwibo, N. (2007). Child health: A Manual for Medical and Health Workers. AMREF.
  • TFNC. (2009). National Guidelines for Nutrition Care and Support for People Living With HIV. Tanzania Food and Nutrition Centre.
  • WHO. (2007). WHO Growth Reference Charts.
  • WHO. (2005). Guidelines for the Management of Common Illnesses with Limited Resources.
  • WHO. (2005). Pocket Book of Hospital Care for Children.