Development of a tool to measure the number of foods and beverages consumed by children using National Health and Nutrition Examination Survey (NHANES) FFQ data

Outliers in nutrient intake data for U.S. adults: national health and nutrition examination survey 2017-2018

Objectives

An important step in preparing data for statistical analysis is outlier detection and removal, yet no gold standard exists in current literature. The objective of this study is to identify the ideal decision test using the National Health and Nutrition Examination Survey (NHANES) 2017-2018 dietary data.

Methods

We conducted a secondary analysis of NHANES 24-h dietary recalls, considering the survey's multi-stage cluster design. Six outlier detection and removal strategies were assessed by evaluating the decision tests' impact on the Pearson's correlation coefficient among macronutrients. Furthermore, we assessed changes in the effect size estimates based on pre-defined sample sizes. The data were collected as part of the 2017-2018 24-h dietary recall among adult participants (N=4,893).

Results

Effect estimate changes for macronutrients varied from 6.5 % for protein to 39.3 % for alcohol across all decision tests. The largest proportion of outliers removed was 4.0 % in the large sample size, for the decision test, >2 standard deviations from the mean. The smallest sample size, particularly for alcohol analysis, was most affected by the six decision tests when compared to no decision test.

Conclusions

This study, the first to use 2017-2018 NHANES dietary data for outlier evaluation, emphasizes the importance of selecting an appropriate decision test considering factors such as statistical power, sample size, normality assumptions, the proportion of data removed, effect estimate changes, and the consistency of estimates across sample sizes. We recommend the use of non-parametric tests for non-normally distributed variables of interest.

Validation of the FRESH Austin food frequency questionnaire using multiple 24-h dietary recalls

OBJECTIVE

The purpose of the current study was to examine the validity of an FFQ utilised in the Food Retail: Evaluating Strategies for a Healthy Austin (FRESH Austin) study, designed to evaluate changes in the consumption of fruits and vegetables (FV) in diverse low-income communities in Austin, TX.

DESIGN

The FRESH Austin FFQ was validated against three 24-h dietary recalls (24hDR). All dietary assessments were administered (in-person or by telephone) by trained investigators.

SETTING

Recruitment was conducted at sites within the geographic areas targeted in the FRESH Austin recruitment. People at a community health clinic, a local health centre and a YMCA within the intervention area were approached by trained and certified data collectors, and invited to participate.

PARTICIPANTS

Among fifty-six participants, 83 % were female, 46 % were non-White, 24 % had income < $25 K/year and 30 % spoke only/mostly Spanish at home.

RESULTS

The FFQ and average of three 24hDR produce similar estimates of average total servings/d across FV (6·68 and 6·40 servings/d, respectively). Correlations produced measures from 0·01 for 'Potatoes' and 0·59 for 'Other Vegetables'. Mean absolute percentage errors values were small for all FV, suggesting the variance of the error estimates was also small. Bland-Altman plots indicate acceptable levels of agreement between the two methods.

CONCLUSION

These outcomes indicate that the FRESH FFQ is a valid instrument for assessing FV consumption. The validation of the FRESH Austin FFQ provides important insights for evaluating community-based efforts to increase FV consumption in diverse populations.

Eating fish and fruits are associated with lower prevalence of allergic diseases

BACKGROUND

Allergic diseases are recognized as a burden on the public health. They stand as one of the most common chronic diseases, especially in developed countries. Therefore, the objective of this study is to evaluate the association between the development of atopic allergy and the presence of food allergy in children, and food consumption.

METHODS

This multidisciplinary cross-observational epidemiological study was conducted among 1199 schoolchildren who were recruited in 4th grade and 5th grade (9-11 years old from Marseille). Data were collected by means of a standardized epidemiological questionnaire with a medical assessment focusing on allergic diseases, and questions on lifestyle and child nutrition (FFQ).

RESULTS

During the last 12 months, prevalence of allergic diseases were shown as follows: 41% of children presented allergic rhinitis symptoms, 24% reported having asthma related symptoms, while 28% suffered of eczema and 7% complained of food allergy. There was a significant association between food allergy and asthma symptoms (P-value<0.001, IC=[2.29-7.69]), eczema (P-value<0.001, IC=[2.37-8.32]) and allergic rhinitis (P-value<0.001, IC=[2.32-8.17]). Regarding dietary habits, the multivariate analysis shows that the consumption of vegetables (ORa=0.72 [0.64-0.74]) and fish (ORa=0.74 [0.50-1.09], ORa=0.66 [0.47-0.94] respectively) are associated decreased risk of developing asthma and allergic rhinitis symptoms, while fruit consumption (ORa=0.68 [0.45-1.03]) is associated with a decrease in eczema symptoms.

CONCLUSION

This study shows that the presence of a food allergy is strongly associated with allergic diseases. Indeed, the consumption of vegetables, fruits and fish seems to have a protective effect on the occurrence of these diseases.