Validity and reproducibility of a short food frequency questionnaire among patients with chronic kidney disease

Recommended calcium intake in adults and children with chronic kidney disease-a European consensus statement

Mineral and bone disorders (MBD) are common in patients with chronic kidney disease (CKD), contributing to significant morbidity and mortality. For several decades, the first-line approach to controlling hyperparathyroidism in CKD was by exogenous calcium loading. Since the turn of the millennium, however, a growing awareness of vascular calcification risk has led to a paradigm shift in management and a move away from calcium-based phosphate binders. As a consequence, contemporary CKD patients may be at risk of a negative calcium balance, which, in turn, may compromise bone health, contributing to renal bone disease and increased fracture risk. A calcium intake below a certain threshold may be as problematic as a high intake, worsening the MBD syndrome of CKD, but is not addressed in current clinical practice guidelines. The CKD-MBD and European Renal Nutrition working groups of the European Renal Association (ERA), together with the CKD-MBD and Dialysis working groups of the European Society for Pediatric Nephrology (ESPN), developed key evidence points and clinical practice points on calcium management in children and adults with CKD across stages of disease. These were reviewed by a Delphi panel consisting of ERA and ESPN working groups members. The main clinical practice points include a suggested total calcium intake from diet and medications of 800-1000 mg/day and not exceeding 1500 mg/day to maintain a neutral calcium balance in adults with CKD. In children with CKD, total calcium intake should be kept within the age-appropriate normal range. These statements provide information and may assist in decision-making, but in the absence of high-level evidence must be carefully considered and adapted to individual patient needs.

Association of long-term triglyceride-glucose index patterns with the incidence of chronic kidney disease among non-diabetic population: evidence from a functional community cohort

BACKGROUND

The triglyceride-glucose (TyG) index is a reliable surrogate marker of insulin resistance and previous studies have confirmed the association of TyG index with incident chronic kidney disease (CKD). However, the impact of longitudinal patterns of TyG index on CKD risk among non-diabetic population is still unknown. Therefore, this study aimed to investigate the association of longitudinal patterns of TyG index with incident CKD among non-diabetic population.

METHODS

A total of 5484 non-diabetic participants who underwent one health examination per year from 2015 to 2017 were included in this prospective study. TyG index variability and cumulative TyG index were calculated to assess the longitudinal patterns of TyG index. Cox proportional hazard models were performed to estimate the association of TyG index variability or cumulative TyG index with incident CKD.

RESULTS

During a median of 3.82 years follow-up, 879 participants developed CKD. Compared with participants in the lowest quartile, the hazard ratio (HR) and 95% confidence interval (CI) of incident CKD were 1.772 (95% CI: 1.453, 2.162) for the highest TyG index variability quartile and 2.091 (95% CI: 1.646, 2.655) for the highest cumulative TyG index quartile in the fully adjusted models. The best discrimination and reclassification improvement were observed after adding baseline TyG, TyG index variability and cumulative TyG index to the clinical risk model for CKD.

CONCLUSIONS

Both TyG index variability and cumulative TyG index can independently predict incident CKD among non-diabetic population. Monitoring longitudinal patterns of TyG index may assist with prediction and prevention of incident CKD.

Validity and Reproducibility of Food Group-Based Food Frequency Questionnaires in Assessing Sugar-Sweetened Beverage Consumption Habits among Chinese Middle-School Students

Assessing the intake of sugar-sweetened beverages (SSBs) is crucial for reducing obesity; however, a simple but relatively accurate method for determining added sugar consumption among school adolescents is lacking. The aim of this study was to evaluate the reproducibility and validity of a food group-based food frequency questionnaire (FG-FFQ) for SSBs in assessing SSB consumption and added sugar among middle-school students. A total of 242 school students completed the FG-FFQs twice and four discontinuous 24-h dietary records (24HDR) over a three-month period. A weighted average approach was used to obtain the average sugar content in the sugary drink food group (FG). Correlation coefficient, weighted kappa statistic, misclassification analysis, and Bland-Altman plot were used to evaluate the validity and reproducibility of the FG-FFQ. Linear regression was utilized to obtain the calibration formulas. The average content of added sugar in sugary drink FG was 8.1 g/100 mL. SSB consumption frequency, consumption amount, and added sugar had correlation coefficients of 0.81, 0.87, and 0.87, respectively, in the validity analysis (p < 0.05). The majority of scatter plots were covered by 95% confidence intervals in the Bland-Altman bias analysis. The intra-class correlation coefficient of SSB consumption frequency and Spearman correlation coefficient of SSB consumption amount and added sugar were 0.74, 0.81, and 0.90, respectively, in the reproducibility analysis (p < 0.05). Results produced by the FG-FFQ calibration formula were more comparable to 24HDR. The FG-FFQ for SSB consumption showed acceptable validity and reproducibility, making it a viable instrument for epidemiological studies on sugary drinks in adolescents.

Nutritional Epidemiology and Dietary Assessment for Patients With Kidney Disease: A Primer

Nutritional epidemiology seeks to understand nutritional determinants of disease in human populations using experimental and observational study designs. Though randomized controlled trials provide the strongest evidence of causality, the expense and difficulty of sustaining adherence to dietary interventions are substantial barriers to investigating dietary determinants of kidney disease. Therefore, nutritional epidemiology commonly employs observational study designs, particularly prospective cohort studies, to investigate long-term associations between dietary exposures and kidney disease. Due to the covarying nature and synergistic effects of dietary components, holistic characterizations of dietary exposures that simultaneously consider patterns of foods and nutrients regularly consumed are generally more relevant to disease etiology than single nutrients or foods. Dietary intakes have traditionally been self-reported and are subject to bias. Statistical methods including energy adjustment and regression calibration can reduce random and systematic measurement errors associated with self-reported diet. Novel approaches that assess diet more objectively are gaining popularity but have not yet fully replaced self-report and require refinement and validation in populations with chronic kidney disease. More accurate and frequent diet assessment in existing and future studies will yield evidence to better personalize dietary recommendations for the prevention and treatment of kidney disease.

Validation of a Phosphorus Food Frequency Questionnaire in Patients with Kidney Failure Undertaking Dialysis

Nutritional guidelines recommended limiting dietary phosphorus as part of phosphorus management in patients with kidney failure. Currently, there is no validated phosphorus food frequency questionnaire (P-FFQ) to easily capture this nutrient intake. An FFQ of this type would facilitate efficient screening of dietary sources of phosphorus and assist in developing a patient-centered treatment plan. The objectives of this study were to develop and validate a P-FFQ by comparing it with the 24 hr multi-pass recall. Fifty participants (66% male, age 70 ± 13.3 years) with kidney failure undertaking dialysis were recruited from hospital nephrology outpatient departments. All participants completed the P-FFQ and 24 hr multi-pass recalls with assistance from a renal dietitian and then analysed using nutrient analysis software. Bland–Altman analyses were used to determine the agreement between P-FFQ and mean phosphorus intake from three 24 hr multi-pass recalls. Mean phosphorous intake was 1262 ± 400 mg as determined by the 24 hr multi pass recalls and 1220 ± 348 mg as determined by the P-FFQ. There was a moderate correlation between the P-FFQ and 24 hr multi pass recall (r = 0.62, p = 0.37) with a mean difference of 42 mg (95% limits of agreement: 685 mg; −601 mg, p = 0.373) between the two methods. The precision of the P-FFQ was 3.33%, indicating suitability as an alternative to the 24 hr multi pass recall technique. These findings indicate that the P-FFQ is a valid, accurate, and precise tool for assessing sources of dietary phosphorus in people with kidney failure undertaking dialysis and could be used as a tool to help identify potentially problematic areas of dietary intake in those who may have a high serum phosphate.

The simplified iodine-specific food frequency questionnaire can evaluate iodine intake in Chinese adults

We hypothesized that an effective iodine-specific food frequency questionnaire (I-FFQ) simplification method could expand the application of the I-FFQ in evaluating long-term iodine intake. An adult I-FFQ was developed and was simplified by deleting food items with iodine contribution rates ≤0.1%, combining food items with similar species and iodine contribution rates, and calculating the iodine content of combined food by a weighted calculation method. A 3-day (3-d) diet diary tested the validity of the I-FFQ. We evaluated the relationship between iodine intake estimated using the I-FFQ and the urinary iodine to creatinine ratio, thyroid volume (Tvol), and thyroid function. The Kappa value was 0.62 for the original I-FFQ and the 3-d diet diary (P < .001), 0.78 for the short-version I-FFQ and the 3-d diet diary (P < .001), and 0.76 for the original I-FFQ and the short-version I-FFQ (P < .001). The mean difference before and after simplification was 27.1 µg/d. The Tvol was different between the I-FFQ groups and showed an upward trend (P for trend = .01). Tvol was higher in the 284 <I-FFQ <347 µg/d (β = 0.55; 95% CI, 0.06-1.03; P = .03) and I-FFQ >347 µg/d (β = 0.72; 95% CI, 0.16-1.28; P = .01) groups after simplification. The I-FFQ is an effective method for evaluating iodine nutritional status in adults. After streamlining, the food items were reduced from 58 to 15, which shortened the investigation time while retaining evaluation efficiency; it is also easier to get the cooperation of the subjects and improve the availability of I-FFQ.

Using a Short Food Frequency Questionnaire to Evaluate Macronutrients, Fiber, Phosphorus, Potassium, and Calcium in Adults with Stages 3-5 Chronic Kidney Disease

The progression of chronic kidney disease (CKD) can be directly or indirectly accelerated by a poor diet and the diet's influence on risk factors for this disease. There have been no food frequency questionnaires (FFQs) developed for the assessment of diet in patients with CKD in Taiwan. This study analyzed the validity of a short FFQ (SFFQ) with 42 items for estimating patient intake of macronutrients, fiber, phosphorus, potassium, and calcium against 3-day dietary records (3-day DRs) in Taiwanese patients with stages 3-5 CKD. In an interview, 107 participants with the help of a dietician filled out an SFFQ and reviewed a 3-day DR the patients had filled out prior to the interview. Partial Pearson correlation coefficients between SFFQ and 3-day DR were 0.722, 0.619, 0.593, 0.572, 0.450, 0.611 and 0.410 for protein, fat, carbohydrate, fiber, phosphorus, potassium, and calcium, respectively, after adjusting for energy intake. Cross-classification analysis revealed 63.5-83.2% similarity in cross-tool estimated intakes of macronutrients, fiber, phosphorus, potassium, and calcium in the same quartiles or adjacent ones. Bland-Altman plots revealed good agreement between the two tools along different intake levels. In conclusion, the newly developed SFFQ had moderate relative validity in estimating the usual intake of key nutrients related to nutrition management of patients with late-stage CKD, suggesting it can be used to assess dietary intakes in a population with CKD, especially in those residing in an Asian region.

Probiotic Intake and Inflammation in Patients With Chronic Kidney Disease: An Analysis of the CKD-REIN Cohort

Background and Aims

Little is known about the effects of probiotics on inflammation in the context of chronic kidney disease (CKD). We investigated the association between probiotic intake and inflammation in patients with moderate-to-advanced CKD.

Methods

We performed a cross-sectional study of 888 patients with stage 3–5 CKD and data on serum C-reactive protein (CRP) levels and a concomitant food frequency questionnaire. We estimated the odds ratios (ORs) [95% confidence interval (CI)] for various CRP thresholds (>3, >4, >5, >6, and >7 mg/L) associated with three intake categories (no yoghurt, ordinary yoghurt, and probiotics from yoghurts or dietary supplements) and two frequency categories (daily or less than daily).

Results

The 888 study participants (median age: 70; men: 65%) had a median estimated glomerular filtration rate of 28.6 mL/min/1.73 m² and a median [interquartile range] CRP level of 3.0 [1.6, 7.0] mg/L. Fifty-seven percent consumed ordinary yoghurt and 30% consumed probiotic yoghurt. The median intake frequency for yoghurt and probiotics was 7 per week. Relative to participants not consuming yoghurt, the ORs [95% CI] for CRP > 6 or >7 mg/L were significantly lower for participants consuming ordinary yoghurt (0.58 [0.37, 0.93] and 0.57 [0.35, 0.91], respectively) and for participants consuming probiotics (0.54 [0.33, 0.9] and 0.48 [0.28, 0.81], respectively), independently of age, sex, body mass index, CKD stage, cardiovascular disease, and fibre, protein and total energy intakes. The ORs were not significantly lower for CRP thresholds >3, >4, and >5 mg/L and were not significantly greater in daily consumers than in occasional consumers.

Conclusion

We observed independent associations between the consumption of yoghurt or probiotics and lower levels of inflammation in patients with CKD. There was no evidence of a dose-effect relationship.

Clinical Trial Registration

[https://www.clinicaltrials.gov/ct2/show/NCT03381950], identifier [NCT03381950].

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.

Development and Relative Validity of the Chronic Kidney Disease Short Food Frequency Questionnaire (CKD SFFQ) to Determine Diet Quality and Dietary Habits among Adults with Chronic Kidney Disease

Limited instruments are available to determine diet quality among US adults with chronic kidney disease (CKD). The purpose of this study was two-fold: (1) to develop a food frequency questionnaire, CKD SFFQ, for adults with CKD and (2) to validate the CKD SFFQ against two 24-h recalls in determining diet quality (DQ). A 57-item CKD SFFQ was developed through a content validation method. Adults with CKD (n = 46) completed the CKD SFFQ and 2-24-h recalls. Statistical analyses included descriptive statistics, frequencies, t-tests, Pearson correlations, and Bland-Altman plots. All data were analyzed using JMP SAS v15 with statistical significance detected at p < 0.05. Results showed no differences for the overall DQ (p = 0.11) and the nine whole-food components (p = 0.07 to p = 0.44) when comparing the CKD SFFQ to the 2-24-h recalls. Pearson correlation coefficients ranged from -0.39 (refined grains) to 0.60 (greens and beans). Bland-Altman plots showed overall good agreement and there was a systematic trend towards higher estimates with the CKD SFFQ, particularly for overall DQ, total proteins, and dairy. The majority of participants rarely or never consumed grains, fruits, vegetables, seafood, and plant proteins. The CKD SFFQ was demonstrated to be an acceptable method to determine DQ for adults with CKD.

Effects of sevelamer carbonate versus calcium acetate on vascular calcification, inflammation, and endothelial dysfunction in chronic kidney disease

Hyperphosphatemia is present in most patients with end‐stage renal disease (ESRD) and has been associated with increased cardiovascular mortality. Phosphate binders (calcium‐based and calcium free) are the mainstay pharmacologic treatment to lower phosphorus levels in patients with ESRD. We evaluated biochemical markers of vascular calcification, inflammation, and endothelial dysfunction in patients with chronic kidney disease (CKD) treated with sevelamer carbonate (SC) versus calcium acetate (CA). Fifty patients with CKD (stages 3 and 4) were enrolled and assigned to treatment with SC and CA for 12 weeks. At the end of the study the biomarkers of vascular calcification, inflammation, and endothelial dysfunction were analyzed. A significant increase in HDL‐cholesterol was observed with SC but not with CA in patients with CKD. Treatment with SC reduced serum phosphate, calcium phosphate, and FGF‐23 levels and there was no change with CA treatment. The inflammatory markers IL‐8, IFN‐γ, and TNFα decreased with response to both treatments. The levels of IL‐6 significantly increased with CA treatment and no change was observed in the SC treatment group. SC showed favorable effects on anti‐inflammatory and vascular calcification biomarkers compared to CA treatment in patients with CKD stages 3 and 4 with normal phosphorous values.

Development and Validation of a Novel Food-frequency Questionnaire for Hemodialysis Patients in Lucknow, India

Introduction:

Food-frequency questionnaire (FFQ) is a preferred tool for longitudinal dietary assessment and has been recently validated in patients on hemodialysis in other countries. As dietary habits vary vastly across regions, this study was planned to develop and validate a novel dialysis FFQ in northern India.

Materials and Methods:

Dietary recall data from patients on hemodialysis available from the previous year were used for identifying food items for inclusion in the FFQ. A nutrient database was created to estimate energy, protein, calcium, phosphorus, and potassium content of the foods included in the food list. The FFQ was validated against a 2-day dietary recall method (one predialysis, one on the dialysis day) in patients on maintenance hemodialysis in a tertiary care hospital in Lucknow, northern India.

Results:

Dietary recall data from 78 patients on hemodialysis were used for the generation of the FFQ. A total of 84 patients completed the validation study. All the nutrients measured by the FFQ correlated significantly with the means of the 2-day dietary record (r values 0.31–0.76) both in crude- and energy-adjusted intakes. De-attenuation further improved the correlation (0.35–0.80). Bland-Altman plots showed higher estimates by FFQ than by dietary recall. Cross-classification analysis showed correct classification in the exact or adjacent quintile (average 60%) by both methods and 2% gross misclassification. Weighted kappa showed fair agreement for energy intake and slight agreement for others.

Conclusion:

This novel semiquantitative FFQ is a valid tool for measuring energy and nutrient intakes in hemodialysis patients.

Validation of a six-item dietary calcium screening tool among HIV patients in China

OBJECTIVE

Individuals with HIV are at increased risk for osteoporosis. A healthy diet with adequate Ca is recommended to promote bone health. However, lengthy nutritional assessments pose barriers to routine screenings in clinical practice. This study aimed to examine the validity and reproducibility of a six-item dietary Ca screening tool among Chinese individuals with HIV.

DESIGN

We conducted a two time-point study in an outpatient setting. Volunteers self-administered the six-item tool upon enrolment and again at 1-month follow-up. At baseline, participants also completed a validated FFQ and surveys regarding demographic and clinical risk factors.

SETTING

Beijing, China; Shenzhen, Guangdong, China.

PARTICIPANTS

Upon enrolment, 127 individuals with HIV participated in the study, of whom 83 completed the follow-up screening.

RESULTS

Mean age of participants was 35·2 (sd 9·3) years, average BMI was 22·8 (sd 3·8) kg/m2 and 89 % were men. Among the participants, 54·7 % reported Ca intake less than 800 mg/d. The six-item tool demonstrated fair-to-moderate relative validity with a correlation of 0·39 and 75·7 % of subjects classified in same/adjacent quartiles as the reference, and moderate-to-good reproducibility with a correlation of 0·60 and 83·1 % of subjects classified in same/adjacent quartiles. Finally, receiver operating characteristic analyses yielded a sensitivity of 87·0 % and a specificity of 39·4 % with optimised cut-off level.

CONCLUSIONS

The six-item tool presented adequate validity and reproducibility to identify individuals with low Ca intake among the target population, providing a convenient instrument for categorising Ca intake in clinical practice, prompting referrals for further assessment, and raising awareness of dietary Ca in bone disease prevention.

An Evaluation of Nephrology Literature for Transparency and Reproducibility Indicators: Cross-Sectional Review

INTRODUCTION

Reproducibility is critical to diagnostic accuracy and treatment implementation. Concurrent with clinical reproducibility, research reproducibility establishes whether the use of identical study materials and methodologies in replication efforts permits researchers to arrive at similar results and conclusions. In this study, we address this gap by evaluating nephrology literature for common indicators of transparent and reproducible research.

METHODS

We searched the National Library of Medicine catalog to identify 36 MEDLINE-indexed, English-language nephrology journals. We randomly sampled 300 publications published between January 1, 2014, and December 31, 2018.

RESULTS

Our search yielded 28,835 publications, of which we randomly sampled 300 publications. Of the 300 publications, 152 (50.7%) were publicly available, whereas 143 (47.7%) were restricted through paywall and 5 (1.7%) were inaccessible. Of the remaining 295 publications, 123 were excluded because they lack empirical data necessary for reproducibility. Of the 172 publications with empirical data, 43 (25%) reported data availability statements and 4 (2.3%) analysis scripts. Of the 71 publications analyzed for preregistration and protocol availability, 0 (0.0%) provided links to a protocol and 8 (11.3%) were preregistered.

CONCLUSION

Our study found that reproducible and transparent research practices are infrequently used by the nephrology research community. Greater efforts should be made by both funders and journals. In doing so, an open science culture may eventually become the norm rather than the exception.

Prevalence and Correlates of Sarcopenia among Elderly CKD Outpatients on Tertiary Care

Background: Sarcopenia is a widespread concern in chronic kidney disease (CKD) as well in elderly patients and is one of the main reasons why low-protein diets for this population are controversial. The aim of this study was to assess the prevalence and correlates of sarcopenia among elderly male patients affected by CKD followed up in an outpatient nephrology clinic, where moderate protein restriction (0.6–0.8 g/Kg/day) is routinely recommended to patients in CKD stage 3b-5 not on dialysis. Methods: This observational study included 80 clinically-stable male out-patients aged >60, affected by stage 3b-4 CKD. Forty patients aged ≥75 (older seniors) were compared to the other forty patients aged 60–74 (younger seniors). All patients underwent a comprehensive nutritional and functional assessment. Results: Older seniors showed lower serum albumin, hand-grip strength, body mass index (BMI), skeletal muscle mass, and resting energy expenditure. Protein intake was significantly lower in older seniors whereas energy intake was similar. Average daily physical activity was lower in the older seniors than in the younger ones. Sarcopenia was more prevalent in older than in younger seniors. Among older seniors, sarcopenic and non-sarcopenic ones differed in age and performance on the Six-Minute Walk test, whereas the estimated glomerular filtration rate (eGFR), biochemistry, dietary protein, and energy intakes were similar. Conclusions: Older senior CKD male patients have lower muscle mass, muscle strength, and physical capacity and activity levels, with a higher prevalence of sarcopenia than younger patients. This occurs at the same residual renal function and metabolic profile and protein intake. Energy intake was at the target in both subgroups. In this CKD cohort, sarcopenia was associated with age and physical capacity, but not with eGFR or dietary intakes.

Relative Validity and Reproducibility of a New 44-Item Diet and Food Frequency Questionnaire Among Adults: Online Assessment

Background

Dietary questionnaires currently available which can assess the habitual diet are timely, costly, or not adapted well to the modern diet; thus, there is a need for a shorter food frequency e-Questionnaire (FFeQ) adapted to Western diets, in order to properly estimate energy and macronutrient intakes or rank individuals according to food and nutrient intakes.

Objective

The aim of this study was to evaluate the relative validity and reproducibility of a 30-minute and 44-item FFeQ in a sample of adults obtained from the general population.

Methods

A sample of French adults was recruited through social media and an advertising campaign. A total of 223 volunteers completed the FFeQ twice at one-year intervals and were included in the reproducibility study. During that interval, 92 participants completed three-to-six 24-hour recalls and were included in the validity study. Nutrient and dietary intakes were computed for all validity and reproducibility participants. The level of agreement between the two methods was evaluated for nutrient and food group intakes using classification into quintiles of daily intake, correlation coefficients and Bland-Altman plots.

Results

For relative validity, correlation coefficients ranged from 0.09 to 0.88 (unadjusted correlation coefficients, median: 0.48) and 0.02 to 0.68 (deattenuated and energy adjusted correlation coefficients, median: 0.50) for food group and nutrient intakes, respectively. The median proportion of subjects classified into the same or adjacent quintile was 73% and 66% for food and nutrient intakes, respectively. Bland-Altman plots showed good agreement across the range of intakes. Regarding reproducibility, intraclass correlation coefficients ranged from 0.33 to 0.72 (median: 0.60) and 0.55 to 0.73 (median: 0.64), for food and nutrient intakes, respectively.

Conclusions

The FFeQ showed acceptable validity and reproducibility in a sample of adults based on their food and nutrient intakes. The FFeQ is a promising and low-cost tool that can be used in large-scale online epidemiological studies or clinical routines and could be integrated into evidence-based smartphone apps for assessing diet components.

Potential applications of a new short food frequency questionnaire for CKD patients

Diet is among the most modifiable risk factors for chronic kidney disease (CKD) progression. Studies of beneficial dietary patterns for persons with CKD have largely utilized dietary assessment measures developed in individuals without CKD. In BMC Nephrology, Affret et al. report on their study of the reproducibility of a newly developed short 49-item food frequency questionnaire (SFFQ) adapted to patients with CKD. Here, we discuss potential applications of this SFFQ, towards better understanding of which dietary patterns portend the most favorable outcomes in CKD.