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Validation Information: Oxford FFQ
Comparison of dietary assessment methods in nutritional epidemiology: weighed records v. 24 h recalls, food-frequency questionnaires and estimated-diet records
Women (n 160) aged 50 to 65 years were asked to weigh their food for 4d on four occasions over the period of 1 year, using the PETRA (Portable Electronic Tape Recorded Automatic) scales. Throughout the year, they were asked to complete seven other dietary assessment methods: a simple 24h recall, a structured 24h recall with portion size assessments using photographs, two food-frequency questionnaires, a 7d estimated record or open-ended food diary, a structured food-frequency (menu) record, and a structured food-frequency (menu) record with portion sizes assessed using photographs. Comparisons between the average of the 16d weighed records and the first presentation of each method indicated that food-frequency questionnaires were not appreciably better at placing individuals in the distribution of habitual diet than 24h recalls, due partly to inaccuracies in the estimation of frequency of food consumption. With a 7d estimated record or open-ended food diary, however, individual values of nutrients were most closely associated with those obtained from 16d weighed records, and there were no significant differences in average food or nutrient intakes
Total number of nutrients validated: 14
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:
- Saturated Fat
- Mono-unsaturated Fat
- Poly-unsaturated Fat
- Non‐starch polysaccharides(NSP)
- Folic Acid
- Vitamin B12
- Vitamin C
- Fruit & Vegetables
- Urinary Nitrogen
To find information on the other validated nutrients please read the validation study.
- Macronutrients: 7
- Micronutrients: 6
|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|
|Weighed Food Diary||Adults||Female Only||Energy (kcal)||234||495||0.52 (S)||46||4||-755||1224|
|Energy (kJ)||980||2070||0.52 (S)||46||4||-3160||5120|
|Protein (g)||13||20||0.43 (S)||39||4||-27||53|
|Fat (g)||11||26||0.55 (S)||38||4||-41||63|
|Carbohydrates (g)||22||65||0.55 (S)||39||4||-108||152|
|Total Sugars (g)||26||48||0.51 (S)||44||4||-70||122|
|Fibre (NSP) (g)||3||6||0.57 (S)||43||4||-9||15|
|Calcium (mg)||356||392.8||0.50 (S)||46||4||-429.5||1141.5|
|Iron (mg)||0.7||6.4||0.43 (S)||39||4||-12.0||13.4|
|Retinol (µg)||213||833.3||0.55 (S)||47||4||-1453.6||1879.6|
|Vitamin C (mg)||23||46.3||0.54 (S)||37||4||-69.6||115.6|
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.
Bingham SA, Gill C, Welch A, Day K, Cassidy A, Khaw KT, et al. Comparison of dietary assessment methods in nutritional epidemiology: weighed records v. 24 h recalls, food-frequency questionnaires and estimated-diet records. British Journal of Nutrition. 1994 Oct 1;72(04):619-43.