Handling random errors and biases in methods used for short-term dietary assessment

Epidemiological studies have shown the effect of diet on the incidence of chronic diseases; however, proper planning, designing, and statistical modeling are necessary to obtain precise and accurate food consumption data. Evaluation methods used for short-term assessment of food consumption of a population, such as tracking of food intake over 24h or food diaries, can be affected by random errors or biases inherent to the method. Statistical modeling is used to handle random errors, whereas proper designing and sampling are essential for controlling biases. The present study aimed to analyze potential biases and random errors and determine how they affect the results. We also aimed to identify ways to prevent them and/or to use statistical approaches in epidemiological studies involving dietary assessments

Ultra-Processed Food Consumption and Risk of Type 2 Diabetes:Three Large Prospective U.S. Cohort Studies

OBJECTIVE We examined the relationship between ultra-processed food (UPF) intake and type 2 diabetes (T2D) risk among 3 large U.S. cohorts, conducted a meta-analysis of prospective cohort studies, and assessed meta-evidence quality. RESEARCH DESIGN AND METHODS We included 71,871 women from the Nurses’ Health Study, 87,918 women from the Nurses’ Health Study II, and 38,847 men from the Health Professional Follow-Up Study. Diet was assessed using food frequency questionnaires and UPF was categorized per the NOVA classification. Associations of total and subgroups of UPF with T2D were assessed using Cox proportional hazards models. We subse-quently conducted a meta-analysis of prospective cohort studies on total UPF and T2D risk, and assessed meta-evidence quality using the NutriGrade scoring system. RESULTS Among the U.S. cohorts (5,187,678 person-years; n = 19,503 T2D cases), the haz-ard ratio for T2D comparing extreme quintiles of total UPF intake (percentage of grams per day) was 1.46 (95% CI 1.39–1.54). Among subgroups, refined breads; sauces, spreads, and condiments; artificially and sugar-sweetened beverages; an-imal-based products; and ready-to-eat mixed dishes were associated with higher T2D risk. Cereals; dark and whole-grain breads; packaged sweet and savory snacks; fruit-based products; and yogurt and dairy-based desserts were associated with lower T2D risk. In the meta-analysis (n = 415,554 participants; n = 21,932 T2D cases), each 10% increment in total UPF was associated with a 12% (95% CI 10%–13%) higher risk. Per NutriGrade, high-quality evidence supports this relationship. CONCLUSIONS High-quality meta-evidence shows that total UPF consumption is associated with higher T2D risk. However, some UPF subgroups were associated with lower risk in the U.S. cohorts.</p

Development, Validation, and Reproducibility of Food Group-Based Frequency Questionnaires for Clinical Use in Brazil: A Pre-Hypertension and Hypertension Diet Assessment

The Blood pressure control diet is well described; however, it has not been implemented in clinical care, possibly due to the impracticability of the diet assessment in these contexts. In order to facilitate the dietary assessment, we developed and assessed the validity and reproducibility of two food group-based food frequency questionnaires (FG-FFQs), with a one-week (7-day FG-FFQ) and a one-month (30-day FG-FFQ) period of coverage for patients with pre-hypertension or hypertension. In 2010, 155 men and women, 30–70 years old, were invited to participate in a prospective study in two outpatient clinics in Porto Alegre, southern Brazil. The participants responded to two 30-day, two 7-day FG-FFQ, four 24-h dietary recalls, and underwent demographic, anthropometric, and blood pressure assessments. The validity and reproducibility were assessed using partial correlation coefficients adjusted for sex and age, and the internal validity was tested using the intra-class correlation coefficient. The participants were aged 61 (±10) years and 60% were women. The validity correlation coefficient was higher than r = 0.80 in the 30-day FG-FFQ for whole bread (r = 0.81) and the 7-day FG-FFQ for diet/light/zero soda and industrialized juices (r = 0.84) in comparison to the 24-h dietary recalls. The global internal validity was α = 0.59, but it increased to α = 0.76 when 19 redundant food groups were excluded. The reproducibility was higher than r = 0.80 for pasta, potatoes and manioc, bakery goods, sugar and cocoa, and beans for both versions. The 30-day had a slightly higher validity, both had good internal validity, and the 7-day FG-FFQ had a higher reproducibility

Ultraprocessed foods, unprocessed or minimally processed foods, and risk of frailty in a cohort of United States females

Background: Ultraprocessed foods (UPFs) and poor diet quality have been associated with frailty but existing studies had relatively short follow-up time. It is also unclear whether the association of UPF was primarily due to its correlation with poorer diet quality. Objectives: We examined the association between unprocessed or minimally processed foods (UMFs) and UPF and risk of frailty and explored whether the association with UPF was mainly driven by poor diet quality. Methods: In total, 63,743 nonfrail females aged 60+ y from the Nurses’ Health Study (cohort study) were followed up for ≥26 y. Diet was assessed every 4 y by food frequency questionnaires. UPF and UMF intakes were calculated using the Nova classification. Diet quality was estimated using the Alternate Healthy Eating Index (AHEI) 2010. The association of UMF and UPF with risk of frailty was examined using multivariable adjusted Cox proportional hazard model. Results: During the follow-up period, we recorded 15,187 incident cases of frailty. The hazard ratio (HR) of frailty for the highest compared with the lowest quintile of UMFs (servings per day) was 0.86 (95% CI: 0.83, 0.95; P-trend &lt; 0.001). However, this was no longer statistically significant after adjustment for AHEI-2010. UPFs (servings per day) was directly associated with risk of frailty, even after adjustment for AHEI-2010 (1.31; 95% CI: 1.23, 1.39; P-trend &lt; 0.001). Among those at the highest category of the AHEI-2010, UPFs remained directly associated with frailty (HR comparing top with bottom quintile: 1.40; 95% CI:1.24, 1.57; P-trend &lt; 0.001). For UPF components, we found a higher frailty risk with each serving per day of artificial and sugar-sweetened beverages; fat, spreads, and condiments; yogurt and dairy-based desserts; and other UPFs. However, processed whole grains were not associated with frailty. Conclusions: Higher intake of UPF is associated with a higher risk of frailty in older females. This is not explained by a lower diet quality contributed by UPFs.</p

Efficacy of an Educational Intervention for Sodium Restriction in Patients with Hypertension: A Randomized Controlled Trial

There is sound evidence showing the efficacy of non-pharmacological interventions in lowering blood pressure (BP); however, adherence is usually poor. Interventions to induce behavioral changes aim to improve the ability to read labels, choose foods, and eat low-sodium meals, reinforcing adherence to sodium restriction. In this randomized parallel-controlled trial, we assessed the effectiveness of an educational intervention using the Dietary Sodium Restriction Questionnaire (DSRQ) scores. A follow-up period of 6 months was conducted. Participants were randomized into (1) an educational intervention provided by a registered dietitian on individual visits and dietary planning; (2) a control group with the usual care and dietary recommendations. Patients underwent 24-h ambulatory BP monitoring, 12-h fasting blood tests, spot urine collection, and assessment using DSRQ. We randomized 120 participants (67.5% women and 68.3% Caucasians), and 25 participants were lost to follow-up. The 24-h sodium urinary excretion changed in the control (Δ −1610 mg/day; 95% confidence interval [CI] −1800 to −1410) and intervention groups (Δ −1670 mg/day; 95% CI −1800 to −1450) over time. There was no significant difference in the 24-h estimated sodium between groups. In hypertensive patients, DSRQ-based educational intervention is effective for improving the ability to detect and overcome obstacles to a low-sodium restriction diet but is as effective as dietary recommendations for lowering sodium

Seasonal variation in food intake and the interaction effects of sex and age among adults in southern Brazil

Background/Objective: Because studies have evidenced variations 1 in nutrient intake, further investigation of the interaction between demographic characteristics and the seasons is necessary. We aimed to test the differences in food intake throughout the seasons and the interaction between the seasons and sex and age. Methods: This study included 273 individuals. Food intake was evaluated with 24-hour dietary recalls, and the reported food items were sorted into food groups. We performed the test on the differences in intake of food groups throughout the seasons with repeated measures and on the interaction by using the Generalized Estimate Equation (GEE). Results: Intake of fruits and natural fruit juices and sweetened beverages was lower, while that of grains and derivatives was higher in the winter. The intake of leafy vegetables and fish and seafood was lower in the autumn. The consumption of coffee and eggs was higher in the spring. Ingestion of chocolate powder and sugar, salt, and lean poultry was higher in the winter. The variation in consumption of grains and derivatives, eggs, fatty poultry, and processed meat over the seasons was more likely to be modified by sex. Age interacted with the seasons for leafy vegetables, beans and lentils, lean beef, lean poultry, low fat milk and light yogurt, vegetable oil and unsalted margarine, chocolate powder and sugar, and processed meat. Conclusion: This study shows that food intake may change seasonally and that seasonal variation depends on sex and age, which might aggregate a specific co-variation component