Validation of dietary intakes of protein and energy against 24 hour urinary N and DLW energy expenditure in middle-aged women, retired men and post-obese subjects: comparisons with validation against presumed energy requirements

Abstract

Objectives: To compare validation of reported dietary intakes from weighed records against urinary nitrogen excretion and energy expenditure measured by DLW, and to examine the utility of the Goldberg cut-off for EI:BMR in the identi®cation of under-reporters. Design: Energy (EI) and nitrogen (protein) intake (NI) were measured by 16 d of weighed diet records collected over 1 y. They were validated against urinary nitrogen excretion in 5±8 (mean 6.0) 24 h urine collections and total energy expenditure (EE) measured by doubly labelled water (DLW). Basal metabolic rate (BMR) as measured by whole body calorimetry in women or bedside ventilated hood (Deltatrac) in men. Individual subjects were identi®ed as under-reporters if Urine N:NI was b 1.00 or if EI:EE was`0.79. The agreement between the two ratios in detecting under-reporting was examined. The results from the direct validation by DLW were also compared with validation using the Goldberg cut-off for EI:BMR . Subjects: Eighteen women aged 50±65 y and 27 men aged 55±87 y were selected from participants in two larger dietary surveys as representing the full range of dietary reporting as measured by Urine N:NI. Data from a previous study of 11 post-obese subjects were also included. Results: The two ratios, Urine N:NI and EI:EE, were signi®cantly related (r 70.48, P`0.01). Using the above cut-offs, seven (4F, 3M) subjects were identi®ed as under-reporters by both methods, one (1M) by Urine N:NI only and 8 (3F, 5M) by EI:EE only. There was close agreement in post-obese subjects where 6 subjects showed a substantial degree of under-reporting by both methods (r 70.87, P`0.001). The correlation between direct validation by DLW and EI:BMR est was 0.65 (P`0.001). Some limitations of the Goldberg cutoff for identifying individual under-reporters were demonstrated. Conclusions: EI:EE provides an estimate of the degree of under-reporting of energy at the group and individual level. Urine N:NI identi®es under-reporting of protein intake and the most obvious under-reporters of energy, but is probably of lesser value in estimating the overall degree of under-reporting of energy at group level. Good validation by EI:BMR depends on knowledge of physical activity at both group and individual level. However, the correlation of 0.65 between EI:EE and EI:BMR est suggests that EI:BMR could be usefully incorporated into analysis of data from epidemiological studies. Validation measures consisting of at least predicted EI:BMR ratios and urinary measures should be incorporated into dietary surveys.

Validation of food diary method for assessment of dietary energy and macronutrient intake in infants and children aged 6–24 months

“…Although good agreement between measured metabolizable intake and observed energy intake calculated from dietary intake assessment methods has been demonstrated (Davies et al, 1994), several other studies have reported underestimations of habitual intake Livingstone et al, 1990Livingstone et al, , 1992Schoeller et al, 1990;Black et al, 1997). Work by Davies et al (1994) and the present study indicate a moderate but not signi®cant bias of weighed food records against doubly labelled water in infants and young children.…”

Validation of dietary intakes measured by diet history against24 h urinary nitrogen excretion and energy expenditure measuredby the doubly-labelled water method in middle-aged women

“…The present study found a correlation of 0⋅68 between urinary N and DLW EE, but excluding two extreme values reduced the correlation to 0⋅32 (NS). In a larger body of data (including the present data) (Black et al 1997), the correlation between urinary N excretion and DLW EE was 0⋅36 (n 45) (P Ͻ 0⋅05), but that between urinary N excretion and protein intake was 0⋅80 (excluding under-reporters). Thus, these methods are not completely interchangeable.…”

“…The criterion for under-reporting (EI : EE Ͻ 0⋅79) tends to identify a higher proportion of under-reporters than the criterion urinary N : NI Ͼ1⋅0. It is uncertain whether this is due to inherent differences in the criteria or to genuine differences in the reporting of protein and energy (Black et al 1997). As an alternative to measured EE, EI : BMR has limitations as a validator.…”

Yogurt consumption is associated with higher nutrient intake, diet quality and favourable metabolic profile in children: a cross-sectional analysis using data from years 1–4 of the National diet and Nutrition Survey, UK

“…The methods used to determine energy misreporting in children and adolescents have been described in detail previously [22]. Briefly, energy misreporting was assessed using Goldberg's cut-off2 criterion [23,24], which uses 95% confidence limits to statistically compare the ratio of reported energy intake (EI) to basal metabolic rate (BMR) with physical activity level (PAL). PAL was adapted to children and corresponded to light physical activity (1.45-1.60 depending on age and gender) [22].…”