Diet quality of Montreal-area adults needs improvement: estimates from a self-administered food frequency questionnaire furnishing a dietary indicator score.

OBJECTIVE/DESIGN: Time and budget constraints limit nutrition evaluation in Canadian health surveys. To encourage regular population diet monitoring in Canada, we developed and assessed the relative validity of a population-based food frequency questionnaire (FFQ) to assess usual diet in Quebecers. A 73-item, self-administered semiquantitative FFQ was designed in French and English from the Block National Cancer Institute Health Habits and History Questionnaire to capture usual food consumption among Quebec adults. The US Department of Agriculture Healthy Eating Index (HEI) (maximum score=100) was adapted to Canadian age- and sex-specific dietary recommendations, validated, and programmed to score the FFQ for diet quality. SUBJECTS: The FFQ was pretested, pilot tested, and administered by mail to a random sample of 248 adults aged 18 to 82 years in the Montreal area (57% women) who were recruited by random digit dialing (64% response rate). A subgroup (n=94) furnished four nonconsecutive 1-day food records for validation of the FFQ. RESULTS: Mean FFQ energy intakes were 2,216 kcal (median 2,110 kcal) for men and 1,785 kcal (median 1,680 kcal) for women. Proportional median macronutrient consumption was similar in both sexes at 17% protein, 34% to 35% fats, and 48% to 49% carbohydrates, but differed by age group in women. Adequacy of micronutrient intakes relative to Dietary Reference Intakes varied by age, sex, and nutrient. Whereas most mean or median intakes were at or exceeded recommendations, calcium intakes were low overall and levels of several other nutrients were very low at the 10th percentile. Mean Canadian HEI (range 46 to 99) was higher in women (74.9) than men (70.3, P<.001). Women's scores showed they met recommendations for intakes of vegetables and fruit, cholesterol, and sodium better than men (P ranged from <.01 to <.0001), while men fared better at meeting recommended fat intake levels (P<.05). CONCLUSIONS: The Canadian HEI adequately discriminates overall diet quality based on dietary data estimated from our FFQ. Examination of subscores within and between quartiles may best reveal which food groups require attention to improve diet quality, providing valuable information for teaching and planning. Future studies should test diet quality indicators in populations recruited to reflect greater dietary diversity and reporting ability and include members of disadvantaged groups to provide a broader set of behaviors that could shed light on factors influencing diet quality.

Development and validation of a food frequency questionnaire.

Regular diet monitoring requires a tool validated in the target population. A 73-item, semiquantitative, self-administered food frequency questionnaire (FFQ), was adapted in French and English from the Block National Cancer Institute Health Habits and History Questionnaire. The FFQ was used to capture usual long-term food consumption among adults living in Quebec. A representative sample of adults aged 18 to 82 (57% female) was recruited by random digit dialling in the Montreal region. Approximately 64% of recruits completed and returned the instrument by mail (n=248). The FFQ was validated in a subsample (n=94, 61% female) using four nonconsecutive food records (FRs). Median energy intakes (in kcal) for men and women, respectively, were FFQ (total sample) 2,112 and 1,823, FFQ (subsample) 2,137 and 1,752, and FR (subsample) 2,510 and 1,830. Spearman correlation analyses between FFQ and FR nutrients were positive (with r ranging from 0.32 for folate to 0.58 for saturated fatty acids) and statistically significant (p<0.001), with better results among women. On average, cross-classification of energy and 24 nutrients from the FFQ and means of four FRs placed 39% into identical quartiles and 78% into identical and contiguous quartiles, with only 4% frankly misclassified. These results suggest that the FFQ is a relatively valid instrument for determining usual diet in Quebec adults.

Underreporting of energy intake from a self-administered food-frequency questionnaire completed by adults in Montreal.

BACKGROUND: Energy intake determined from self-reported dietary assessment methods may be underreported. Therefore, it is important that such methods be validated against another with known validity for energy intake or energy expenditure. METHODS: We investigated potential underestimation of energy intake obtained from our semi-quantitative food-frequency questionnaire (FFQ) administered between 2000 and 2001 in the metropolitan area of Montreal, Canada. The study population included 246 adults aged 18 to 82 years. The ratio of energy intake to estimated basal metabolic rate (EI/BMR) was used to assess underreporting and physical activity was determined from self-administered questions. Comparison of the EI/BMR ratio with the Goldberg statistical cut-off allowed us to detect individuals who were low energy reporters (LERs). LERs and non-LERs were compared to determine if they differed on sociodemographic, anthropometric and lifestyle variables. RESULTS: The EI/BMR ratio was 1.26 for men and 1.32 for women. LERs represented 43% of the sample of individuals. Male LERs accounted for 54% compared with 35% among females. Underreporting of energy intake was highest in men and individuals who were older, heavier, with higher body mass index and lower education level. A higher proportion of male LERs perceived their financial situation as adequate while a greater proportion of female LERs considered themselves poor. CONCLUSION: Our data suggest that underreporting of energy intake from the FFQ was considerable and may bias dietary interpretation. As this was uneven across the sample, it is crucial to recognise the characteristics of LERs in order to increase the validity of reported energy intake.

Diet quality among older Quebecers as assessed by simple indicators.

To determine whether older Quebecers are eating adequately and whether summary scores represent diet quality, a representative subset of participants aged 55 to 74 (weighted n=460, 47% male) was studied from the 1990 Enquête québécoise sur la nutrition dataset. Participants' diet quality was scored from adjusted 24-hour recalls. Foods were coded into Canada's Food Guide to Healthy Eating food groups. Usual Dietary Adequacy Score (maximum=18) and Dietary Diversity Score (maximum=4) were calculated from adjusted food guide portions and validated internally in relation to achievement of nutrient recommendations using correlation analysis. Average usual Dietary Adequacy Score (mean +/- standard error) was 14.96 +/- 0.15 (men) and 13.72 +/- 0.15 (women). Only 7% of men and 1% of women achieved the maximum usual score. Forty-four percent of men and 45% of women scored a usual Dietary Diversity Score of 3, and 55% of men and 50% of women achieved 4. Thus, approximately half of older Quebecers showed inadequate dietary variety, and consumed fewer than the minimum recommended number of servings from certain food groups. Summary diet quality indicators are useful for tracking diet quality, and provide critical data for planning nutrition education programs targeting older persons.

An approach for evaluating lifelong intakes of functional foods in elderly people.

Many "functional foods" (FF), common foods with health benefits beyond their nutritive value, have antioxidant properties with the potential to mediate the degenerative changes of aging. A pilot study was conducted among 51 healthy, home-dwelling elderly people aged 70-86 y (51% male) to develop a method for evaluating relationships between lifelong diet and health. A population-based semiquantitative food frequency questionnaire (FFQ) was used to assess the usual diet. A nonquantitative questionnaire (FF-FFQ) was developed to examine current intake patterns of 33 FF, and at ages 65, 45, 25 and 10 y. Visual and memory cues were employed to help respondents remember past intakes, and their reporting confidence was queried. The instrument was self-administered (among 35%), or administered by a dietitian-interviewer in face-to-face (39%) or telephone (25%) interviews. The FFQ was validated by four dietary recalls statistically adjusted for intraindividual and seasonal variability. The FF-FFQ reliability was assessed in a subsample (n = 20). Mean usual FFQ-derived energy intakes were 7941 +/- 2071 kJ (men) and 7033 +/- 1916 kJ (women). Reported current, regular (several times/mo) FF numbered 18 +/- 4 (men) and 20 +/- 4 (women). These means decreased almost linearly with time; at age 10 y, FF reported were 12 +/- 7 (men) and 15 +/- 4 (women). Men differed from women in their memory of food consumption, food choices and FF intakes. Instrument reliability was good, with 73% identical responses. Food-related memory appears to be linked to dietary knowledge, food preparation experience and availability of foods in the past. The FF-FFQ provides novel data on lifetime FF consumption that may help clarify relationships between diet and health, and the role of diet in aging.

Contaminant exposure among women of childbearing age who eat St. Lawrence River sport fish.

Little information is available concerning the level of consumption and degree of contaminant exposure for North American women of childbearing age who eat sport fish. The authors reanalyzed a 1995-1996 study of Montreal-area (Canada) sport fishers. The authors focused on women sport fishers of childbearing age and male sport fishers who had spouses of childbearing age. The primary research involved an on-site questionnaire about fish consumption, with follow-up assessment of sport fishers estimated to have either the highest or lowest levels of fish-based contaminant exposure. Among the 1,654 interviewees were 100 women less than 45 yr of age who had eaten sport fish for an average of 11 yr; 45% ate fish less than once a month. From the follow-up subsample of high- and low-level consumers, the authors identified 17 women less than 45 yr of age and 25 males whose spouses who were less than 45 yr of age and who consumed similar quantities of sport fish. Among this group of 42, the high-exposure women differed from the low-exposure women with respect to their yearly consumption of freshwater fish, blood mercury levels (median = 6.4 vs. 1.4 microgram/l), and plasma polychlorinated biphenyl congener 99 (median = 10.5 vs. 5.9 microgram/kg plasma lipids). Few Montreal-area women of childbearing age consume local sport fish frequently or for extended periods. However, among the small proportion that consumes sport fish frequently or for extended periods, blood mercury concentrations approach levels of concern for fetal protection.