Relative validation of a food frequency questionnaire for national health and nutrition monitoring

Nutrition Journal

Table 3 Agreement of quartiles for food group intake assessed by the food frequency questionnaire and two 24-hour dietary recalls*

	Agreement of quartiles for food group intake (all participants)
Food group	Same quartile%	Adjacent quartile%	Opposite quartile%	Weighted Kappa	95%- Confidence Interval
Coffee	50.3	44.1	0.0	0.54	0.45 - 0.62
Butter and margarine	50.3	40.4	0.6	0.51	0.42 - 0.60
Sweet spreads	48.4	39.0	1.3	0.49	0.40 - 0.59
Milk	45.6	40.3	1.9	0.45	0.35 - 0.55
Non alcoholic beverages	49.0	33.6	3.4	0.45	0.34 - 0.56
Meat products	40.4	44.7	1.9	0.39	0.29 - 0.49
Water	38.4	44.2	2.2	0.36	0.25 - 0.47
Fresh fruits	39.7	37.9	4.9	0.34	0.23 - 0.44
Sweets	40.2	39.0	5.0	0.31	0.20 - 0.43
Bread	38.6	39.9	5.2	0.29	0.18 - 0.41
Raw vegetables	29.8	45.0	10.1	0.18	0.07 - 0.29
Meat	29.4	40.6	10.0	0.15	0.04 - 0.26
Potatoes	30.6	38.2	9.4	0.15	0.04 - 0.26
Cooked vegetables	31.0	37.3	7.0	0.09	-0.03 - 0.20

*Analysis was not performed for food groups with more than 25% of the participants who did not consume this food in the 24-hour dietary recalls.

ISSN: 1475-2891