Validation Information: Weighed Food Diary (DONALD)
Bokhof 2010
Validation of protein intake assessed from weighed dietary records against protein estimated from 24 h urine samples in children, adolescents and young adults participating in the Dortmund Nutritional and Longitudinally Designed (DONALD) Study
Objective: To date, only a few nutritional assessment methods have been validated against the biomarker of urinary-N excretion for use in children and adolescents. The aim of the present study was to validate protein intake from one day of a weighed dietary record against protein intake estimated from a simultaneously collected 24 h urine sample.
Design: Cross-sectional analyses including 439 participants of the Dortmund Nutritional and Longitudinally Designed (DONALD) Study from four age groups (3-4, 7-8, 11-13 and 18-23 years). Mean differences, Pearson correlation coefficients (r), cross-classifications and Bland–Altman plots were used to assess agreement between methods.
Results: Weighed dietary records significantly underestimated mean protein intake by -6.4 (95% CI -8.2, -4.7) g/d or -11 %, with the difference increasing across the age groups from -0.6 (95% CI -2.7, 1.5) g/d at age 3-4 years to -13.5 (95% CI -18.7, -8.3) g/d at age 18-23 years. Correlation coefficients were r=0.7 for the total study sample and ranged from r=0.5 to 0.6 in the different age groups. Both methods classified 85% into the same/adjacent quartile for the whole study group (83-86% for the different age groups) and 2.5% into the opposite quartile (1.9-3.1% for the different age groups). Bland-Altman plots for the total sample indicated that differences in protein intake increased across the range of protein intake, while this bias was not obvious within the age groups.
Conclusions: Protein intake in children and adolescents can be estimated with acceptable validity by weighed dietary records. In this age-heterogeneous sample, validity was lower among adolescents and young adults.
Total number of nutrients validated: 1
Not all of the nutrients validated in the validation studies are included in the table below, as statistical data was only selected to be displayed for a number of nutrients, this included:
- Energy
- Fat
- Saturated Fat
- Mono-unsaturated Fat
- Poly-unsaturated Fat
- Carbohydrates
- Protein
- Sugar
- Non‐starch polysaccharides(NSP)
- Sodium
- Calcium
- Iron
- Zinc
- Retinol
- Folate
- Folic Acid
- Vitamin B12
- Vitamin C
- Fruit & Vegetables
- Urinary Nitrogen
To find information on the other validated nutrients please read the validation study.
- Macronutrients: 1
- Micronutrients: 0
| Comparator | Lifestage | Sex | Nutrient Measured | Mean Difference | Standard Deviation | Correlation Coefficient | Cohen's Kappa Coefficient | Percentage Agreement | Percentage Agreement Categories | Lower Limits of Agreement | Upper Limits of Agreement |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Biomarkers | Children (3-4 years) | Both | Protein (g) | -0.6 | 0.52 (P) | 85.6 | 4 | ||||
| Biomarkers | Children (7-8 years) | Both | Protein (g) | -5.0 | 0.56 (P) | 83.2 | 4 | ||||
| Biomarkers | Adolescents | Both | Protein (g) | -6.8 | 0.59 (P) | 83.3 | 4 | ||||
| Biomarkers | Adolescents, Adults | Both | Protein (g) | -13.5 | 0.48 (P) | 86.4 | 4 | ||||
| Biomarkers | Children, Adolescents, Adults | Both | Protein (g) | -6.4 | 0.70 (P) | 84.5 | 4 |
Some results have been calculated using statistical techniques based on the published data.
For further information on statistical terms click on Statistical tests used in validation studies
All correlations coefficients in the table are unadjusted unless stated otherwise. For adjusted correlation coefficients and other statistical methods used in the study e.g. paired t-tests, please read the validation articles.
- # Adjusted
- † Energy adjusted.
- ‡ For loge-transformed, energy-adjusted nutrient intakes.
- ^ Adjacent included.
- ᵟ Participants provided identical responses.
- (w) = Weighted.
Bokhof B, Günther AL, Berg-Beckhoff G, Kroke A, Buyken AE. Validation of protein intake assessed from weighed dietary records against protein estimated from 24 h urine samples in children, adolescents and young adults participating in the Dortmund Nutritional and Longitudinally Designed (DONALD) Study. Public health nutrition. 2010 Jun;13(6):826-34.