[Association Between Dietary Knowledge and Food Preferences in Residents Aged 18 and Over in China Based on Latent Class Analysis].

Objective To investigate the food preferences and explore the potential association between dietary knowledge and food preferences in residents aged 18 and over in China,so as to provide a basis for promoting healthy diets.Methods The latent class analysis was carried out with the 2015 cross-sectional data of China health and nutrition survey to categorize the food preferences among 8 783 residents aged 18 and over.Multinomial Logistic regression was adopted to assess the association between and dietary knowledge and food preferences.Results The food preferences of the residents aged 18 and over in China were classified into preference for less vegetable(3.28%),lack of preference(11.20%),diverse preferences(4.19%),and preference for healthy diets(81.33%).The proportion of the adults with dietary knowledge was 36.87%(3 238/8 783).The dietary knowledge varied in the adults with different food preferences(all P<0.001).After adjusting for gender,age,urban and rural distribution,education background,and annual household income,for each point increase in the dietary knowledge score,there was an estimated reduction of 22% in the probability of preferring less vegetables(OR=0.78,95%CI=0.76-0.80, P<0.001),13% in the probability of lacking preference(OR=0.87,95%CI=0.86-0.89, P<0.001),and 3% in the probability of having diverse preferences(OR=0.97,95%CI=0.94-1.00, P=0.030).Compared with those lacking dietary knowledge,the individuals with dietary knowledge had a 77% less probability of preferring less vegetables(OR=0.23,95%CI=0.16-0.32, P<0.001),a 55% less probability of lacking preference(OR=0.45,95%CI=0.39-0.53, P<0.001),and a 23% less probability of having diverse preferences(OR=0.77,95%CI=0.61-0.96, P=0.023).Conclusions The residents aged 18 and over in China presented four food preferences,including preference for less vegetables,lack of preference,diverse preferences,and preference for healthy diets,the last of which had the highest proportion.The individuals with lower levels of dietary knowledge have higher probability of preferring unhealthy food.

[Comparison on Performance of Quantitative Ultrasound and Dual-Energy X-ray Absorptiometry in Evaluating Bone Health of Adults Aged 18-40 Years].

Objective To compare the consistency of quantitative ultrasound(QUS)and dual-energy X-ray absorptiometry(DXA)in measuring bone mineral density(BMD)of adults aged 18-40 years in Guangzhou and evaluate the diagnostic value of QUS for identifying low bone mass.Methods DXA was employed to measure the BMD and QUS to measure the speed of sound(SOS)in 731 participants.The Bland-Altman analysis was performed to evaluate the consistency of Z scores between SOS and BMD.With the BMD Z ≤-2.00 as the diagnostic criterion for low bone mass,the receiver operating characteristics curve of QUS was established,and the area under the curve(AUC)and the sensitivity,specificity,and correct diagnostic index for the optimal cut-off of SOS Z score were calculated.Results The results of Bland-Altman analysis showed that the mean differences in the Z scores of SOS and BMD in males and females were 1.27(-0.94 to 3.47)and 0.93(-1.33 to 3.18),respectively.The AUC of SOS Z score in the diagnosis of low bone mass in males and females was 0.734(95%CI=0.380-0.788)and 0.679(95%CI=0.625-0.732),respectively.In males,the optimal cut-off of SOS Z score for low bone mass was -0.35,with the sensitivity,specificity,and correct diagnostic index of 64.1%,68.6%,and 0.327,respectively.In females,the optimal cut-off value of SOS Z scores for low bone mass was -1.14,with the sensitivity,specificity,and correct index of 73.9%,54.8%,and 0.285,respectively.Conclusion QUS and DXA show poor consistency in the diagnosis of BMD in the adults aged 18-40 years in Guangzhou,while QUS demonstrates an acceptable value in identifying low bone mass.