Nutritional Status

• Nutritional status


  The current body status, of a person or a population group, related to their state of nourishment (the consumption and utilization of nutrients)
• Factors affecting nutritional status


  • Internal/constitutional factors (age, sex, nutrition, behavior, physical activity and diseases)
  • External environmental factors (food safety, cultural, social and economic circumstances)
• Ideal nutritional status


  When the supply of nutrients conforms to the nutritional requirements or needs

  
• Factors affecting the balance of nutrients include physiologic, physical, developmental, cultural and economic
• Diets are rated according to the balance of nutrients they provide, and not solely on the type of food eaten or the amount of calorie intake by the food pyramid guide

  
• Nutritional status


  • Optimal nutritional status
  • Undernutrition (severe underweight)
  • Overnutrition (morbid obesity)

  
• Optimal nutritional status


  • Sufficient nutrients are consumed to support day to day body needs and any increased metabolic demands (Growth, illness, pregnancy)
  • It is a powerful factor for health and well-being, a major modifiable and powerful element in promoting health, preventing and treating diseases and improving the quality of life

  
• Malnutrition


  • May increase risk of (susceptibility to) infection and chronic diseases
• Undernutrition


  • Nutrient intake is inadequate to meet day to day need or add metabolic demand
  • Vulnerable groups: infants, pregnant women, low incomes, hospitalized people, aging adults
• Overnutrition


  • Consumption of nutrient in excess of body need
  • Can lead to obesity and risk for heart disease, type 2 Diabetes Mellitus, Hypertension, stroke, Gall Bladder disease, sleep apnea, and osteoarthritis
• Nutritional assessment


  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

  
• Components of nutritional assessment

  • Anthropometric measurements
  • Biochemical parameters
  • Clinical Methods
  • Dietary Methods

  
• Anthropometric methods


  • Measurement of body height, weight & proportions
  • Measurements are compared to reference data to evaluate nutritional status
  • Indicate general nutritional status but don't identify specific nutritional deficiencies
  • Used to evaluate both under & over nutrition
  • Reflect current nutritional status, don't differentiate between acute & chronic changes

  
• Other anthropometric measurements


  • Mid-arm circumference
  • Skin fold thickness
  • Head circumference
  • Head/chest ratio
  • Hip/waist ratio
• Height measurement


  1. Subject stands erect & bare footed on a stadiometer with a movable head piece

  2. Head piece is leveled with skull vault & the height is recorded to the nearest 0.5 cm
• Weight measurement


  1. Use a regularly calibrated electronic or balanced-beam scale

  2. Weigh in light clothes, no shoes

  3. Read to the nearest 100 gm (0.1kg)

  
• Body Mass Index (BMI)


  • The international standard for assessing body size in adults
  • Computed as Weight (kg)/ Height (m²)

  
• Example BMI calculation: Weight = 68 kg, Height = 165 cm (1.65 m) BMI= 68 ÷ (1.65) 2 = 24.98 kg/ m²

  
• Interpretation of BMI for adults

  BMI is interpreted using standard weight status categories that are the same for all ages, and for both men and women

  
• Waist measurement


  1. Waist circumference is measured at the level of the umbilicus to the nearest 0.5 cm

  2. Subject stands erect with relaxed abdominal muscles, arms at the side, and feet together

  3. Measurement should be taken at the end of a normal expiration
• Waist circumference


  • Predicts mortality better than any other anthropometric measurement
• Waist circumference levels


  • Level 1 (Males > 94 cm, Females > 80 cm)
  • Level 2 (Males > 102 cm, Females > 88 cm)
• Waist circumference levels


  • 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
• Hip circumference measurement


  1. Measured at the point of greatest circumference around hips & buttocks to the nearest 0.5 cm

  2. Subject should be standing

  3. Measurements taken with a flexible, non-stretchable tape in close contact with the skin, but without indenting the soft tissue
• Waist/Hip Ratio (WHR)


  • High risk WHR= > 0.80 for females & > 0.95 for males (waist measurement > 80% of hip measurement for women and > 95% for men indicates central (upper body) obesity and is considered high risk for diabetes & CVS disorders)
  • WHR below these cut-off levels is considered low risk
• Body Mass Index (BMI) is used to assess body size in children and teens

  
• Clinical assessment


  • Essential feature of all nutritional surveys
  • Utilizes physical signs associated with malnutrition and deficiency of vitamins & micronutrients
  • Includes obtaining good nutritional history and general clinical examination

  
• Dietary assessment methods


  • 24 hours dietary recall
  • Food frequency questionnaire
  • Dietary history since early life
  • Food diary technique
  • Observed food consumption

  
• 24 hours dietary recall


  • A trained interviewer asks the subject to recall all food & drinks taken in the previous 24 hours
  • Quick, easy & depends on short-term memory, but may not be truly representative of the person's usual intake

  
• Food frequency questionnaire


  • Subject is given a list of around 100 food items to indicate intake (frequency & quantity) per day, per week & per month
  • Inexpensive, more representative & easy to use
  • Limitations: long questionnaire, errors with estimating serving size, needs updating with new commercial food products

  
• Dietary history


  • Aims to discover the usual food intake pattern of individuals over a relatively long period of time
  • Interview method composed of two parts: 1) overall eating pattern and 24hr recall, 2) estimating portion sizes
  • Advantages: estimates nutrient intakes over a long period of time
  • Disadvantages: takes about one hour, requires experienced interviewer

  
• Food diary


  • Food intake (types & amounts) should be recorded by the subject at the time of consumption
  • Collection period range between 1-7 days
  • Reliable but difficult to maintain

  
• Observed food consumption


  • The meal eaten by the individual is weighed and contents are exactly calculated
  • Characterized by having a high degree of accuracy but expensive & needs time & efforts

  
• Initial laboratory assessment


  • Lab tests based on blood and urine can be important indicators of nutritional status, but they are influenced by non-nutritional factors as well
  • Lab results can be altered by medications, hydration status, and disease states or other metabolic processes, such as stress
  • Biochemical data need to be viewed as a part of the whole
• Hemoglobin estimation


  The most important test & useful index of the overall state of nutrition, tells about anemia, protein & trace element nutrition
• Other initial lab tests

  • Stool examination for ova and/or intestinal parasites
  • Urine dipstick & microscopy for albumin, sugar and blood
• Specific lab tests


  • Measurement of individual nutrient in body fluids (e.g. serum retinol, serum iron, urinary iodine, vitamin D)
  • Detection of abnormal amount of metabolites in the urine (e.g. urinary creatinine/ hydroxyproline ratio)
  • Analysis of hair, nails & skin for micronutrients
• Advantages of biochemical methods

  • Useful in detecting early changes in body metabolism & nutrition before the appearance of overt clinical signs
  • Precise, accurate and reproducible
  • Useful to validate data obtained from dietary methods
• Limitations of biochemical methods

  • Time consuming, expensive, cannot be applied on large scale, needs trained personnel & facilities