Validity of food and nutrient intakes assessed by a food frequency questionnaire among Chinese adults.

BACKGROUND: Studies regarding the validity of the food frequency questionnaire (FFQ) and the food composition table (FCT) are limited in Asian countries. We aimed to evaluate the validity of a 64-item FFQ and different methods of constructing the FFQ FCTs for assessing dietary intakes of foods and nutrients among adults in eastern China. METHODS: A total of 2325 participants (aged 56.2 ± 14.9 years, 51.6% female) from nine cities in Zhejiang province who completed a 64-item FFQ and 3-day 24-hour dietary recalls (24HRs) in 2015 were included. Eight FFQ FCTs were generated covering food items and specific weights estimated using professional knowledge, representative 24HRs data, or the Chinese FCT (CFCT). Energy-adjusted intakes of foods and nutrients were estimated by residual and energy density methods. Spearman correlation coefficients (SCCs) of intakes of 14 food groups and 17 nutrients between FFQ and 24HRs were calculated to evaluate the overall validity of FFQ. RESULTS: The average intakes of most food groups and nutrients assessed with FFQ were higher than those assessed using the 24HRs. For the food groups, the averaged energy-adjusted (residual method) SCC between FFQ and 24HRs was 0.27, ranging from 0.14 (starch-rich beans) to 0.49 (aquatic products). For nutrient assessment, the weighted FCT (WFCT) performs the best, and the averaged energy-adjusted (residual method) SCC was 0.26, ranging from 0.16 (iron) to 0.37 (potassium). Similar correlations with 24HRs were observed when using other FFQ FCT in the calculation of nutrient intakes. CONCLUSION: The 64-item Chinese FFQ and the WFCT were reasonably valid to assess the dietary intakes of certain foods and nutrients among adults in eastern China.

Mediterranean-Dietary Approaches to Stop Hypertension Intervention for Neurodegenerative Delay (MIND) Diet and Cognitive Function and its Decline: A Prospective Study and Meta-analysis of Cohort Studies.

BACKGROUND: Evidence on the association of the Mediterranean-Dietary Approaches to Stop Hypertension Intervention for Neurodegenerative Delay (MIND) diet with cognitive aging is limited and inconsistent. OBJECTIVES: We examined how the MIND diet is related to cognitive function and its decline among middle-aged and older adults. METHODS: We included 4066 participants with baseline dietary assessment and ≥1 cognitive test from the China Health and Nutrition Survey in 1997, 2000, 2004, and 2006, with a median follow-up of 3 y. The modified MIND diet score (range: 0-12) was calculated based on 9 healthy and 3 unhealthy food groups. Linear mixed-effect models were used to examine the association of adherence to the MIND diet with z-scores of cognitive function and cognitive decline. We also conducted a meta-analysis including our findings and 7 other cohort studies. RESULTS: At baseline, the median MIND diet scores across increasing tertile were 3.0, 4.0, and 5.5, respectively. Participants with higher MIND diet scores had better global cognitive function. The adjusted difference in global cognitive function z-score for every 3-point increment of MIND diet scores was 0.110 [95% confidence interval (CI), 0.060, 0.159, P-trend < 0.001], which was approximately equivalent to being 1 y younger in age. Consumption of nuts, fish, red meats, and tea showed independent positive associations with cognitive function, while fried food consumption exhibited inverse associations. In the meta-analysis of 26,103 participants, one standardized deviation increment of the MIND score was associated with 0.042 (95% CI: 0.020, 0.065) units higher in global cognitive function z-score and 0.010 (95% CI: -0.001, 0.021) units slower in annual cognitive decline. CONCLUSIONS: Our findings suggest that higher adherence to the MIND diet was associated with better cognitive function and potentially slower cognitive decline in later life. Further large-scale observational and interventional studies are warranted to elucidate the cognitive effects of the MIND diet. This meta-analysis was registered at PROSPERO as CRD42022330417.