assessment of nutritional status

• Experimental procedure


  1. Assessment of nutritional status and energy metabolism conducted at the International Centre for the assessment of Nutritional Status (ICANS), University of Milan

  2. Anthropometric measurements and resting energy expenditure evaluated on the same morning

  3. Dual-energy X-ray absorptiometry (DXA) performed on a sub sample of children

  4. Evaluation of food intake completed at the Human Nutrition and Eating Disorders Research Centre, University of Pavia in all children
• Anthropometric measurements


  1. Taken by the same operator, according to conventional criteria and measuring procedures

  2. Body Weight (BW, Kg) and Body Height (BH, cm) measured to the nearest 100 g and 0.5 cm respectively

  3. When child not able to maintain erect position, BW assessed measuring parent's weight with child in their arms and subtracting the weight of parent, and BH measured using supine length

  4. Body Mass Index (BMI) calculated using the formula: BMI (Kg/m2) = BW (Kg)/BH2 (m2)

  5. All measurements performed on the non-dominant side of the body

  6. Measurements made in triplicate for all sites and the average of the three values calculated for subsequent analysis

  7. BW and BH compared with the standards for linear growth derived from the Tanner-Whitehouse growth charts and the percentage of ideal BW (%BW) and ideal BH (%BH) for sex and age at 50th percentile calculated

  8. Cut-off point of malnutritional status identified at 80% of the weight for age value

  9. According to Waterlow classification, children defined as "stunted" when their %BH was lower than 80% compared with the reference height for age

  10. BW also expressed as a percentage of ideal weight for height, sex, and age (%IBWH)

  11. Children classified as "wasted" when their %IBW-H was lower than 90% compared with reference values
• Body composition assessment


  1. Measurements of fat mass (FM, Kg), fat free mass (FFM, Kg) and bone mineral content (BMC, g) performed with a Lunar DPX-IQ scanner (Lunar Corp, Madison, WI) equipped with a pediatric software (version 4.6 b)

  2. Total body scans performed with subjects in the supine position, beginning at the top of the head, with the "medium t" scan mode

  3. Mean measurement time 15 min; radiation exposure < 7 μSv

  4. Daily quality-assurance tests performed according to the manufacturer's directions

  5. All scans performed and analyzed by the same operator
• Resting energy expenditure

  1. Estimated by indirect calorimeter using an open-circuit ventilated-hood system (Sensor Medics 29, Anaheim, CA)

  2. Measurements made in post-absorptive state (12–14 h fast) in a thermoneutral environment (24–26°C) and with no external stimulation

  3. Calorimeter calibrated at the beginning of each test with two reference gas mixtures

  4. Children rested for at least 20 min before the measurements, which were on subjects awake and supine

  5. Approximately 30 min of respiratory gas exchange data collected, with the first 5–10 min discarded to allow children time to acclimatize

  6. Average of the last 20 min of measurements used to determine 24 h REE according to standard abbreviated Weir equation: REE (Kcal/day) = [3.941 VO2 (mL/min) +1.106 VCO2 (mL/min)] * 1.44
• Dietary intake data

  1. Seven days food diary used to collect dietary food intake

  2. Parents trained by dietician in food recording procedures

  3. When food record completed, family came to the Human Nutrition and Eating Disorders Research Centre, and each day of the food record assessed for completeness by a trained dietician

  4. Incomplete days excluded from the nutrient analysis

  5. Food records coded and analysed using the Dieta Ragionata software (Esi Stampa Medica srl, Milano, Italiy)

  6. Total energy intake (EI, kcal), proteins, lipids, carbohydrates, some minerals and vitamins (calcium, phosphate, potassium, iron, zinc, copper, tiamin, riboflavin, niacin, vitamin A vitamin C) calculated and compared with European Recommended Dietary Allowances for sex and age

  7. Adequacy index calculated according to the formula: daily nutrient intake (g)/recommended allowance (g) for sex and age * 100