Validation of a newly automated web-based 24-hour dietary recall using fully controlled feeding studies

BACKGROUND: Assessment of food intake is a cornerstone of nutritional research. However, the use of minimally validated dietary assessment methods is common and can generate misleading results. Thus, there is a need for valid, precise and cost-effective dietary assessment tools to be used in large cohort studies. The objective is to validate a newly developed automated self-administered web-based 24-h dietary recall (R24W), within a population of adults taking part in fully controlled feeding studies. METHODS: Sixty two adults completed the R24W twice while being fed by our research team. Actual intakes were precisely known, thereby allowing the analysis of the proportion of adequately self-reported items. Association between offered and reported portion sizes was assessed with correlation coefficients and agreement with the kappa score while systematics biases were illustrated with Bland-Altman Plot. RESULTS: Participants received an average of 16 food items per testing day. They reported 89.3% of the items they received. The more frequently omitted food categories were vegetables included in recipes (40.0%) as well as side vegetables (20.0%) and represented less than 5% of the actual daily energy intake. Offered and self-reported portion sizes were significantly correlated (r = 0.80 P < 0.001) and demonstrated a strong agreement as assessed by the kappa score of 0.62. Reported portion sizes for individual food items were on average 3.2 g over the offered portion sizes. Portions of 100 g and above were on average underestimated by 2.4% (r = 0.68 P < 0.01; kappa score = 0.50) while small portions (less than 100 g) were overestimated by 17.1% (r = 0.46 P < 0.01; kappa score = 0.43). A nonsignificant underestimation (−13.9 kcal ± 646.3 kcal; P = 0.83) of energy intake was noted. CONCLUSION: R24W performed well as participants were able to report the great majority of items they ate and selected portion size strongly related to the one they received. This suggests that food items are easily to find within the R24W and images of portion sizes used in this dietary assessment tool are adequate and can provide valid food intake evaluation

Effects of a dietary intervention promoting the adoption of a Mediterranean food pattern on fast-food consumption among healthy French-Canadian women

It is expected that a dietary intervention based on the traditional Mediterranean food pattern should be associated with a reduction in fast-food consumption but this has never been tested before. We assessed the impact of a 12-week dietary intervention, promoting the adoption of a Mediterranean food pattern, on fast-food consumption among seventy-one healthy women aged between 30 and 65 years. The dietary intervention consisted of two group sessions and seven individual sessions with a dietitian. To determine the Mediterranean dietary score (MedScore) and fast-food consumption, an FFQ was administered. During the 12-week intervention, the MedScore significantly increased (from 21·1 (SD 3·6) units at baseline to 28·6 (SD 4·4) units at week 12, P,0·0001), while the fast-food consumption significantly decreased (from 51·7 (SD 46·4) g/d at baseline to 20·5 (SD 18·2) g/d at week 12, P,0·0001). Moreover, women who had a higher consumption of fast food at baseline decreased their fast-food consumption to the most (r 20·50, P,0·0001). When four subgroups were formed on the basis of median values of Medscore and fast-food consumption changes, it was found that only the subgroup of women which increased the most their MedScore and decreased the most their fast-food consumption experienced a significant decrease in BMI (P,0·01). In conclusion, a dietary intervention promoting the Mediterranean food pattern led to a decrease in fast-food consumption among healthy women even if it was not a specific target of the intervention. Dietary strategies for increasing intake of healthy foods may be a useful approach for decreasing intake of less healthy foods

Development and validation of the perceived food environment questionnaire in a french-canadian population

Objective: The present study aimed to develop and validate a questionnaire assessing perceived food environment in a French-Canadian population. Design: A questionnaire, the Perceived Food Environment Questionnaire, was developed assessing perceived accessibility to healthy (nine items) and unhealthy foods (three items). A pre-test sample was recruited for a pilot testing of the questionnaire. For the validation study, another sample was recruited and completed the questionnaire twice. Exploratory factor analysis was performed on the items to assess the number of factors (subscales). Cronbach’s a was used to measure internal consistency reliability. Test–retest reliability was assessed with Pearson correlations. Setting: Online survey. Results: Men and women from the Québec City area (n 31 in the pre-test sample; n 150 in the validation study sample). The pilot testing did not lead to any change in the questionnaire. The exploratory factor analysis revealed a two-subscale structure. The first subscale is composed of six items assessing accessibility to healthy foods and the second includes three items related to accessibility to unhealthy foods. Three items were removed from the questionnaire due to low loading on the two subscales. The subscales demonstrated adequate internal consistency (Cronbach’s a=0·77 for healthy foods and 0·62 for unhealthy foods) and test–retest reliability (r=0·59 and 0·60, respectively; both P<0·0001). Conclusions: The Perceived Food Environment Questionnaire was developed for a French-Canadian population and demonstrated good psychometric properties. Further validation is recommended if the questionnaire is to be used in other populations

Sex differences in the impact of the Mediterranean diet on LDL particle size distribution and oxidation

Sex differences have been previously highlighted in the cardioprotective effects of the Mediterranean diet (MedDiet). The objective of this study was to investigate whether sex differences also exist with regard to LDL particle size distribution and oxidation. Participants were 37 men and 32 premenopausal women (24–53 years) with slightly elevated LDL-C concentrations (3.4–4.9 mmol/L) or total cholesterol/HDL-C =5.0. Variables were measured before and after a four-week isoenergetic MedDiet. Sex differences were found in response to the MedDiet for the proportion of medium LDL (255–260 Å) (p for sex-by-time interaction = 0.01) and small, dense LDL (sdLDL; <255 Å) (trend; p for sex-by-time interaction = 0.06), men experiencing an increase in the proportion of medium LDL with a concomitant reduction in the proportion of sdLDL, while an opposite trend was observed in women. A sex difference was also noted for estimated cholesterol concentrations among sdLDL (p for sex-by-time interaction = 0.03), with only men experiencing a reduction in response to the MedDiet. The MedDiet marginally reduced oxidized LDL (oxLDL) concentrations (p = 0.07), with no sex difference. Results suggest that short-termconsumption of the MedDiet leads to a favorable redistribution of LDL subclasses from smaller to larger LDL only in men. These results highlight the importance of considering sex issues in cardiovascular benefits of the MedDie

Carotenoids as biomarkers of fruit and vegetable intake in men and women

High fruit and vegetable (FAV) intake is associated with a lower prevalence of chronic diseases. Identifying the ideal number of FAV servings needed to reduce chronic disease risk is, however, difficult because of biases inherent to common self-report dietary assessment tools. The aim of our study was to examine the associations between daily FAV intake and plasma carotenoid concentrations in men and women enrolled in a series of fully controlled dietary interventions. We compiled and analysed data from a group of 155 men and 109 women who participated in six fully controlled dietary interventions and compared post-intervention fasting plasma carotenoid (a-carotene, ß-carotene, ß-cryptoxanthin, lutein, lycopene, zeaxanthin) concentrations with regard to the daily FAV servings consumed by the participants. We found that plasma ß-cryptoxanthin, lutein and zeaxanthin concentrations were positively associated with daily FAV servings (P=0·005). However, daily FAV intake was negatively associated with plasma a-carotene (P<0·0005) and lycopene (P<0·0001) concentrations, whereas no association was noted with plasma ß-carotene. When men and women were analysed separately, we found that for any given number of FAV servings consumed women had higher circulating lutein concentrations compared with men (P<0·01). Significant sex×FAV (P<0·0001) and sex×dietary ß-cryptoxanthin (P<0·0005) interactions were also noted favouring higher plasma ß-cryptoxanthin concentrations in women than in men for a given FAV consumption. Results from these fully controlled dietary feeding studies indicate that plasma ß-cryptoxanthin and lutein concentrations can be used as robust biomarkers of FAV consumption. They also suggest the existence of sex differences influencing circulating ß-cryptoxanthin and lutein concentrations following FAV consumption

Sex differences in the impact of the Mediterranean diet on systemic inflammation

Background: Some intervention trials have reported a reduction in systemic inflammation with the Mediterranean diet (MedDiet) while others have observed no effect. Despite the fact that sex differences have been highlighted in the inflammatory regulation, it is still not known whether MedDiet exerts similar effects on systemic inflammation in men and women. The aim of this study was therefore to investigate sex differences in the effects of the MedDiet on high-sensitivity C-reactive protein (hs-CRP). Findings: Participants were 35 men and 27 premenopausal women (24–53 years) presenting a slightly deteriorated lipid profile. All foods were provided to participants during a 4-week isocaloric MedDiet. At baseline, women had higher hs-CRP concentrations than men (P¿=¿0.03). No sex difference was observed in hs-CRP response to the MedDiet (P for sex-by-time interaction¿=¿0.36), with both men and women experiencing no change (respectively P¿=¿0.62 and P¿>¿0.99). When subgroups were formed according to hs-CRP concentration before the MedDiet phase, men with elevated baseline values (=2 mg/l) experienced a reduction in hs-CRP over time with the MedDiet (-26.5 %) while an increase was observed in men with lower baseline values (+96.6 %; P for group-by-time interaction¿=¿0.02). This pattern of change was not observed in women. Conclusions: Results from this controlled feeding study suggest that men and women have similar effects from the MedDiet on systemic inflammation. The individual’s overall inflammatory status seems to influence these effects, but only in men

Effects of the traditional Mediterranean diet on adiponectin and leptin concentrations in men and premenopausal women : do sex differences exist?

Background/Objectives: Most of the interventional studies have investigated the impact of the diet on adiponectin and leptin concentrations only in men or in women. Consequently, it is still unknown whether the consumption of a healthy diet influences in a sex-specific manner these adipocytokines. We examined sex differences in the effects of the Mediterranean diet (MedDiet) on adiponectin and leptin concentrations, and determined whether changes in these adipocytokines are associated with changes in cardiovascular risk factors in both sexes. Subjects/Methods: Participants were 38 men and 32 premenopausal women (24–53 years) with slightly elevated low-density lipoprotein cholestrol concentrations (3.4–4.9¿mmol/l) or total cholesterol/high-density lipoprotein cholestrol (HDL-C)greater than or equal to5.0. Adiponectin, leptin and cardiovascular risk factors were measured before and after a 4-week fully controlled isoenergetic MedDiet. Results: Adiponectin concentration decreased in response to the MedDiet, but this decrease reached statistical significance only in men (P<0.001 for men and P=0.260 for women; sex-by-time interaction, P=0.072). Adjustments for body weight or waist circumference did not change results obtained. Changes in adiponectin were positively associated with concomitant variations in HDL-C in men (r=0.52, P=0.003) and with variations in apolipoprotein A-1 and insulin sensitivity as calculated by both the homeostasis model assessment index for insulin sensitivity and Cederholm indices in women (respectively, r=0.44, P=0.021; r=0.79, P<0.001 and r=0.47, P=0.020). The MedDiet had no impact on leptin and the leptin-to-adiponectin ratio in both sexes. Conclusions: Results suggest a sex difference in adiponectin response to the short-term consumption of the MedDiet, with only men experiencing a decrease. Also sex-specific patterns of associations between changes in adiponectin concentration and changes in cardiovascular risk factors were observed

Correlates of the difference in plasma carotenoid concentrations between men and women

Health professionals consider the evaluation of eating habits to be challenging, given the potential biases of dietary questionnaires based on self-reported data. Circulating carotenoid concentrations are reliable biomarkers of dietary carotenoid intake and could be useful in the validation of dietary assessment tools. However, there is a sex difference in circulating carotenoids, with women displaying higher concentrations compared with men independent of intake. The aim of the present study was to identify the correlates of plasma carotenoid concentrations among men (n 155) and women (n 110) enrolled in six fully controlled dietary interventions with varying dietary carotenoid intakes. We looked at the associations of post-intervention fasting plasma carotenoid concentrations (α-carotene, β-carotene, β-cryptoxanthin, lutein, lycopene and zeaxanthin) with physical and metabolic characteristics. We found that increased body weight (r –0·47, P<0·0001) and waist circumference (r –0·46, P <0·0001) were associated with lower plasma total carotenoid concentrations, while elevated plasma LDLcholesterol (r 0·49, P<0·0001) and HDL-cholesterol (r 0·50, P<0·0001) concentrations were correlated with higher total carotenoids in plasma. Women had significantly higher plasma total carotenoid concentrations compared with men, despite significantly lower dietary carotenoid intake. Adjustment of circulating carotenoid concentrations for plasma HDL-cholesterol eliminated sex difference in plasma carotenoid concentrations. Our results suggest that physical characteristics as well as plasma lipids are associated with circulating carotenoid concentrations and that these variables should be taken into account when using plasma carotenoids as biomarkers for food intake in men and women

Gene-diet interactions with polymorphisms of the MGLL gene on plasma low-density lipoprotein cholesterol and size following an omega-3 polyunsaturated fatty acid supplementation : a clinical trial

Background: Omega-3 (n-3) polyunsaturated fatty acid (PUFA) consumption increases low-density lipoprotein (LDL) cholesterol (C) concentrations and particle size. Studies showed that individuals with large, buoyant LDL particles have decreased risk of cardiovascular diseases. However, a large inter-individual variability is observed in LDL particle size. Genetic factors may explain the variability of LDL-C concentrations and particle size after an n-3 PUFA supplementation. The monoglyceride lipase (MGLL) enzyme, encoded by the MGLL gene, plays an important role in lipid metabolism, especially lipoprotein metabolism. The aim of this study was to investigate if polymorphisms (SNPs) of the MGLL gene influence the variability of LDL-C and LDL particle size in response to an n-3 PUFA supplementation. Methods: 210 subjects completed the study. They consumed 5 g/d of a fish oil supplement (1.9-2.2 g eicosapentaenoic acid and 1.1 g docosaexaenoic acid) during 6 weeks. Plasma lipids were measured before and after the supplementation period and 18 SNPs of the MGLL gene, covering 100% of common genetic variations (minor allele frequency ≥0.05), have been genotyped using TaqMan technology (Life Technologies Inc., Burlington, ON, CA). Results: Following the n-3 PUFA supplementation, 55% of subjects increased their LDL-C levels. In a model including the supplementation, genotype and supplementation*genotype effects, gene-diet interaction effects on LDL-C concentrations (rs782440, rs6776142, rs555183, rs6780384, rs6787155 and rs1466571) and LDL particle size (rs9877819 and rs13076593) were observed for the MGLL gene SNPs (p < 0.05). Conclusion: SNPs within the MGLL gene may modulate plasma LDL-C levels and particle size following an n-3 PUFA supplementation. This trial was registered at clinicaltrials.gov as NCT01343342