Diet, Health and Nutritional Assessment
This domain tests how nutrition status is measured and judged: the ABCD model, anthropometric indices and cut-offs, dietary assessment methods, biochemical and clinical signs, and the interpretation of these in Cameroonian settings where undernutrition and overnutrition coexist. Expect both definitions and case interpretation.
The ABCD framework
- Anthropometry: weight, height, mid-upper arm circumference (MUAC), head circumference, skinfold thickness. Derived indices: weight-for-age (underweight), height-for-age (stunting), weight-for-height (wasting), BMI-for-age.
- Biochemical: haemoglobin (anaemia), serum retinol (vitamin A), urinary iodine, serum albumin, ferritin.
- Clinical: oedema, hair and skin changes, Bitot's spots, goitre, angular stomatitis, bow-legs.
- Dietary: 24-hour recall, food frequency questionnaire, weighed food record, household consumption survey, national food balance sheets.
Interpreting anthropometry
Adults: BMI = weight (kg) ÷ height (m)². Below 18.5 underweight; 18.5–24.9 normal; 25–29.9 overweight; ≥ 30 obese. Children 6–59 months: MUAC < 115 mm = severe acute malnutrition; 115–125 mm = moderate. Children are classified using z-scores against WHO growth standards, not adult cut-offs.
Deficiency pictures
- Marasmus: severe wasting, no oedema, from chronic energy deficiency.
- Kwashiorkor: oedema, low serum albumin, fatty liver, hair and skin changes; weight may look near-normal because of fluid.
- Iodine deficiency → goitre and cretinism; vitamin A deficiency → night blindness, xerophthalmia; iron deficiency → microcytic anaemia.
Worked example
An adult woman weighs 68 kg and is 1.62 m tall. BMI = 68 ÷ (1.62)² = 68 ÷ 2.624 = 25.9 kg/m² → overweight. Correct interpretation requires her age and pregnancy status, and BMI does not distinguish fat from muscle. A different trap: a 20-month-old weighing 9 kg with height 80 cm must not be judged against adult BMI bands; use weight-for-height or BMI-for-age z-scores from the WHO standards.
Dietary assessment: choosing and judging
A single 24-hour recall is quick and has low respondent burden but does not represent usual intake and depends on memory; a food frequency questionnaire captures habitual intake but is poor at quantifying portions; a weighed record is accurate but burdensome and may change behaviour. Combining methods raises validity.
Traps
Using adult BMI cut-offs for children; interpreting one recall as usual intake; forgetting oedema in kwashiorkor; confusing stunting (chronic) with wasting (acute); and treating a low BMI as proof of micronutrient deficiency.