BACKGROUND:Dietary self-monitoring is central to effective personalized nutrition, providing critical data to inform tailored feedback and support behavior change. OBJECTIVES:To examine the impact of dietary self-monitoring adherence and the indirect effect of personalized scores to predict postprandial glycemic response (PPGR) on weight loss. METHODS:Post hoc analysis of the Personal Diet Study that investigated the impact of a machine algorithm-based diet that integrates clinical and microbiome features (Personalized) compared with a standard, low-fat diet (Standardized) on weight loss. All participants received behavioral counseling and were encouraged to self-monitor dietary intake via a smartphone application. Personalized received algorithm-based scores (1-5) on predicted PPGR to foods logged (PPGR score; 1-2 indicating optimal; 3-5 suboptimal). Dietary self-monitoring adherence was the percentage of days logging ≥50% of target calories, classified as high or low. PPGR score quality was calculated by the proportion of optimal predicted PPGR scores per day; defined as "high-PPGR quality" days when this exceeded the group average. Mediation analysis assessed whether PPGR quality mediated the relationship between dietary self-monitoring adherence and weight loss. RESULTS:Participants with high self-monitoring adherence lost an average of 4.2% of their baseline weight, compared with 1.9% among those with low adherence (P = 0.016). High self-monitoring adherence was associated with a greater likelihood of achieving ≥5% weight loss (adjusted odds ratio: 3.67; 95% confidence interval: 1.63, 8.50). Within Personalized, high-PPGR quality mediated 53.4% of the total effect of self-monitoring adherence on weight loss (P < 0.001). CONCLUSION:Consistent self-monitoring coupled with personalized feedback may significantly enhance weight loss in a precision nutrition approach. This trial was registered at https://clinicaltrials.gov/ as NCT03336411.

Introduction and Objective: Dietary recommendations for type 2 diabetes (T2D) aim to minimize postprandial glycemic response (PPGR), yet the optimal strategy remains unclear. The impact of precision nutrition on glycemic control is also not well established. Methods: The Diabetes Telemedicine Mediterranean Diet (DiaTeleMed) Study was a fully remote, 6-month, 3-arm randomized controlled trial in U.S. adults (21-80 years) with moderately controlled T2D (HbA1c 6.5-8.0%). Participants were randomized to: (1) usual care control (UCC), (2) a Standardized intervention, or (3) a Personalized intervention. The Standardized arm received 14 behavioral counseling sessions focused on Mediterranean diet-based diabetes self-management; the Personalized arm received all Standardized components plus real-time, algorithm-driven feedback on predicted PPGR. Participants wore a continuous glucose monitor at baseline, 3, and 6 months to assess glycemic variability (GV) metrics, including mean amplitude of glycemic excursions (MAGE). Linear mixed models were used to compare changes in GV between arms. Results: Participants (n=161; UCC: n=59; Standardized: n=61; Personalized: n=41) were 60±12 years, 62.7% female, 46.6% White, 80.7% non-Hispanic; HbA1c was 6.77%±0.6%. The change in MAGE did not differ significantly between UCC and Standardized (p=0.24), UCC and Personalized (p=0.13), or Standardized and Personalized (p=0.70). Changes in other GV metrics were also not significantly different among the arms at 3 and 6 months. At 6 months, the Personalized arm showed a greater reduction in the coefficient of variation (CV) compared with UCC (mean difference: −1.84%; 95% CI: −3.57 to −0.11; p=0.04). Conclusion: In adults with moderately controlled T2D, a precision nutrition intervention using real-time, algorithm-driven PPGR feedback did not improve MAGE or most GV indices beyond usual care or Mediterranean diet-based counseling. Disclosure L. Berube: None. C. Wang: None. M. Curran: None. M. Pompeii: None. C. Thao: None. E.P. Ribeiro: None. S. Barua: None. L. Hu: None. H. Li: None. D.E. St-Jules: None. E. Segal: None. M. Bergman: Advisory Panel; Ended; Novo Nordisk. Advisory Panel; Current; Abbott. C. Popp: Consultant; Current; Longevix. Funding National Institutes of Health (R01NR018916)

Traditional dietary advice for people living with chronic kidney disease (CKD) focused predominantly on the quantity of energy and protein provided by the diet as well as restricting the consumption of single micronutrients. However, flaws in the assumptions that underlie this quantity-based approach have led to re-examination of medical nutrition therapy for kidney-related conditions, with a shift towards recommending more varied and liberalized plant-rich diets with a focus on dietary quality. Although clinical practice guidelines for patients with CKD have cautiously acknowledged this shift, less advice is available on how to translate new knowledge into practical and feasible recommendations that describe which foods patients should be advised to eat. In this Review, we provide a framework for the delivery of quality-oriented diet therapy for people with CKD based on the dietary principles of balance, variety and moderation. This approach also requires consideration of the manner in which foods are processed, prepared and integrated into the diet. Successful implementation requires a flexible, individualized approach that involves consideration of both CKD-specific and general dietary factors as well as potential barriers, challenges and behavioural determinants of the patient’s dietary choices and habits. Here, the authors discuss how to implement quality-focused dietary strategies for patients with chronic kidney disease. They discuss the principles of dietary balance, variety and moderation, food processing and cooking methods and approaches to enabling successful implementation of quality-focused dietary strategies.

Potassium-containing food additives are a broad class of compounds used in food processing and food preparation to enhance the quality, flavor, safety, stability, and health of foods. In 2023, the US Food and Drug Administration encouraged food manufacturers to replace salt with potassium-based salt substitutes, and although this change was intended to reduce hypertension in the general population, excess intake of potassium-based salt substitutes may increase the risk of hyperkalemia in people with kidney failure on dialysis. To assess and address this concern, the American Society of Nephrology produced a kidney health guidance report, which included basic, advanced, and intensive dietary strategies for mitigating hyperkalemia risk from food additives in people with reduced kidney function. The purpose of this review was to refine these recommendations to reduce hyperkalemia risk from potassium additives in patients on dialysis.

OBJECTIVE:The scientific literature on diet therapy for managing hyperkalemia risk in people with kidney disease has shifted in the last decade away from a focus on restricting potassium-rich foods. However, the extent to which this change is reflected in online resources has not been systematically studied. DESIGN AND METHODS:The first 50 webpages from Google and Bing search engines were obtained using the terms "diet" and "potassium" with: 1) hyperkalemia, 2) high blood potassium, 3) kidney disease, 4) dialysis, 5) kidney failure, 6) chronic kidney disease, 7) low, and 8) restriction. Dietary guidance was classified as recommended, restricted, or mixed using a hierarchical approach (e.g., advice to restrict oranges was also counted as restricting citrus fruit and fruit). After removing duplicate (n = 468) and unrelated/excluded resources (n = 224), 106 resources (13.3%) were available for analyses. RESULTS:Online resources provided advice on 559 food items. Fruit and vegetables comprised the majority of restrictions (59%) and recommendations (58%). Plant-based protein foods, low-fat dairy products, and whole grains tended to restricted, and animal-based protein foods, high-fat dairy products, and refined grains tended to be recommended. Dietary guidance was usually at the level of individual food items, often restricting (nectarines) and recommending (peaches) foods in the same sub-group, and more than half of the food items (55%) mentioned in at least two resources had inconsistent advice across resources (restricted and recommended). CONCLUSION:Dietary guidance online for managing hyperkalemia risk did not reflect recent shifts in the literature and primarily consisted of complicated food lists that lacked consistency. Research is needed to standardize and evaluate the efficacy of the food list-based approach to practice.

BackgroundThe gut microbiome is implicated in obesity and type 2 diabetes (T2D), but how diet, body composition, glycemic status, and self-efficacy factors relate to the microbiome in high-risk individuals is not well characterized. The purpose of this post-hoc analysis is to examine the relationship between the gut microbiome and obesity-related metabolic factors, including body composition, resting energy expenditure (REE), and glycemic variability (GV).MethodsData for this post-hoc cross-sectional analysis were obtained from adults with prediabetes and obesity enrolled in The Personal Diet study, a 6-month behavioral weight loss study. Pre-intervention assessments (n = 95) included the collection of fecal microbiome profile, demographics, socioeconomic status, physical and metabolic characteristics [fat mass, fat free mass (FFM), continuous glucose monitoring–derived GV, REE], self-efficacy and dietary intake. Gut bacterial alpha diversity, beta diversity, and genus level abundances were associated with these host and lifestyle variables using multivariate regression, permutational multivariate analysis of variance, and correlation analyses.ResultsParticipants were a mean age of 58 years old, mostly female (75.8%), with a mean BMI of 34.6 kg/m2 and mean HbA1c of 5.7%. Higher FFM was associated with greater alpha diversity, whereas higher BMI was associated with lower diversity (p < 0.05). Dietary factors were the most consistent correlates of gut microbial beta diversity. At the genus level, associations were observed for sex, metformin use, BMI, protein intake, and REE. The Prevotella/Bacteroides ratio was positively associated with total energy, sugar, and carbohydrate intake (g/day) and negatively associated with monounsaturated fat intake (g/day). Glycemic measures and self-efficacy were not associated with any genera.ConclusionIn adults with prediabetes and obesity, the gut microbiome at baseline was most strongly associated with diet, with additional associations observed for body composition and selected host characteristics. These findings underscore diet as a key correlate of gut microbiome structure in a high-risk metabolic population and support further development of microbiome-informed precision nutrition strategies for obesity prevention and management.

Background/Objectives: The aim of this secondary analysis is to determine the baseline characteristics that are associated with a higher likelihood of weight-loss success in a personalized nutrition intervention. Methods: Data were analyzed in adults with abnormal glucose metabolism and obesity from a 6-month behavioral counseling randomized clinical trial. Participants were randomized to two calorie-restricted diets: a low-fat diet (Standardized) or a personalized nutrition diet leveraging a machine learning algorithm (Personalized). The gradient boosting machine method was used to determine the baseline variables (i.e., age, weight-loss self-efficacy) that predicted successful weight loss (≥5%) at 6 months in each study arm separately, using repeated five-fold cross-validation with 100 repetitions. Results: A total of 155 participants (Personalized: n = 84 vs. Standardized: n = 71) contributed data (mean [standard deviation]: age, 59 [10] y; 66.5% female; 56.1% White; body mass index (BMI), 33.4 [4.6] kg/m2). In both arms, higher baseline self-efficacy for weight loss was a predictor of weight-loss success. Participants with a higher BMI (p < 0.0001) in the Standardized arm and those who were older (p < 0.0001) in the Personalized arm were more likely to achieve successful weight loss. Conclusions: Future weight-loss interventions may consider providing tailored behavioral support for individuals based on weight-loss self-efficacy, BMI, and age.

Objective: Continuous glucose monitoring (CGM) consensus guidelines, developed using large CGM datasets in type 1 and insulin-treated type 2 diabetes, recommend 14 days of wear time with at least 70% (~10 days) complete data. We sought to examine whether fewer days could reliably capture glycemic variability measures such as time in range (TIR) in individuals with type 2 diabetes (T2D) not on insulin. Methods: The NIH-funded DiaTeleMed study is a 6-month randomized controlled trial comparing three different dietary strategies in adults diagnosed with T2D managed using diet alone or diet and metformin. We analyzed blinded Freestyle Libre Pro CGM data collected for up to 14 days before the intervention started. For participants with at least 10 complete days of data, we computed their time in 70-140 mg/dL (TIR140) and 70-180 mg/dL (TIR180) range using a cumulative approach starting from the first day and successively adding each day of data until their final day. We then identified the minimum number of days it took for the cumulative TIR metrics to stabilize within a clinically meaningful ±2% of their final values. Results: We analyzed 80 participants (age 60±12 years, 63% female, 47% non-White, 14% Hispanic/Latino, BMI 30±6 kg/m2, HbA1c 6.7±0.6%, 66% on metformin) who had at least 10 days of complete CGM data. Participants’ cumulative TIR stabilized within ±2% of final values in 70±20% of days worn for TIR140 and in 50±23% of days worn for TIR180. Extrapolating these percentages to 14 days of wear, effectively 10±3 days and 7±3 days would be sufficient to estimate TIR140 and TIR180 respectively in this population. Conclusion: Fewer than the 14 recommended days may be sufficient to estimate important CGM-derived metrics such as the TIR in individuals with T2D managed with diet alone or diet plus metformin. CGMs worn for less than the mandated 14-day period due to issues such as device fall-off, discomfort, or malfunction may still provide reliable glycemic variability information. Disclosure S. Barua: None. M. Curran: None. L. Berube: None. C. Popp: None. M. Pompeii: None. J.C. Wang: None. S.M. Vanegas: None. B. Dorcely: None. L. Hu: None. D. St-Jules: None. M. Bergman: None. E. Segal: None. M. Sevick: None. Funding National Institutes of Health (R01-NR018916 )

BACKGROUND:Patients with chronic kidney disease (CKD) are encouraged to choose refined grains instead of whole grains as part of the low-phosphorus diet for managing chronic kidney disease-mineral and bone disorders (CKD-MBD). However, there is no direct evidence indicating that limiting whole grains has a beneficial impact on CKD outcomes. METHODS:This study analyzed Chronic Renal Insufficiency Cohort data in two ways, namely cross-sectional examination of CKD-MBD biomarkers and prospective examination of health outcomes. A total of 4,067 (cross-sectional) and 4,331 (prospective) participants were included. The primary exposure was reported intake of whole grains (analyzed as servings/day, servings/1,000kcal, and refined grain servings/whole grain servings). CKD-MBD biomarkers included serum phosphorus, fibroblast growth factor-23, parathyroid hormone, calcitriol, and calcium. Outcomes included cardiovascular events, kidney failure, and all-cause mortality. RESULTS:In adjusted models, reported intake of whole grains was associated with higher phosphorus intake and serum phosphorus when assessed crudely (serving/day), but not when analyzed in relation to energy. Higher intake of refined grain relative to whole grains was associated (all models) with higher risk of kidney failure (Model 4: 1.01, 95% CI 1.00 to 1.02; P=0.01, all-cause mortality (Model 4: 1.01, 95% CI 1.00 to 1.01; P=0.01), and cardiovasulcar disease except for the fully adjusted model. Higher dietary density was associated with lower mortality in models adjusted for demographic and clinical factors including kidney function, but not in the fully adjusted model that futher adjusted for dietary factors. CONCLUSION:Intake of whole grains was not associated with CKD-MBD biomarkers. Intake of whole grains in relation to refined grains was associated with lower risk of cardiovascular disease, kidney failure, and mortality. The results of this study put into question the long-standing practice of restricting whole grains in patients with chronic kidney disease.

The Diabetes Telemedicine Mediterranean Diet (DiaTeleMed) Study is a fully remote randomized clinical trial evaluating personalized dietary management in individuals with type 2 diabetes (T2D). The study aims to test the efficacy of a personalized behavioral approach for dietary management of moderately controlled T2D, versus a standardized behavioral intervention that uses one-size-fits-all dietary recommendations, versus a usual care control (UCC). The primary outcome will compare the impact of each intervention on the mean amplitude of glycemic excursions (MAGE). Eligible participants are between 21 and 80 years of age diagnosed with moderately controlled T2D (HbA1c: 6.0 to 8.0

Dietetic practice aims to help people modify their diet to slow disease progression and manage disease-related complications while also meeting their nutritional and personal dietary needs. This can be challenging in people with kidney failure undergoing dialysis, particularly in our current food environment and culture. Fortunately, advancements in nutritional-behavioral science and technology are providing new avenues and resources to help meet the challenge. However, progress is slow, and much of dietetic practice in the dialysis population still relies on the interpretation, translation, and application of low-quality, indirect evidence. This Special Issue of Seminars in Dialysis provides readers with an update on and critical insights into some of the major issues and controversies impacting the field of kidney nutrition today.

Excessive dietary phosphorus is a concern among patients with kidney failure undergoing dialysis treatment because it may contribute to hyperparathyroidism and hyperphosphatemia. A long-standing but untested component of the low-phosphorus diet is the promotion of refined grains over whole grains. This paper reviews the scientific premise for restricting whole grains in the dialysis population and estimates phosphorus exposure from grain products based on three grain intake patterns modeled from reported intakes in the general US population, adjusting for the presence of phosphorus additives and phosphorus bioavailability: (1) standard grain intake, (2) 100% refined grain intake, and (3) mixed (50/50 whole and refined grain) intake. Although estimated phosphorus exposure from grains was higher with the mixed grain pattern (231 mg/day) compared to the 100% refined grain pattern (127 mg/day), the amount of additional phosphorus from grains was relatively low. Given the lack of strong evidence for restricting whole grains in people with CKD, as well as the potential health benefits of whole grains, clinical trials are warranted to address the efficacy and health impact of this practice.

OBJECTIVE:Internet search engines and social media websites are prominent and growing sources of dietary information for people with chronic kidney disease (CKD) and their healthcare providers. However, nutrition therapy for CKD is undergoing a paradigm shift, which may lead to inconsistent advice for managing hyperphosphatemia. The aim of this study was to summarize and evaluate online resources for phosphorus-specific nutrition therapy. DESIGN AND METHODS:Patient-facing resources were collected from Google, Yahoo, and Facebook in June-July 2021. Using nine independent search terms, the first 100 hits were reviewed. Dietary advice for food types, food groups, food subgroups, and individual food items was categorized as "restricted," "recommended," "mixed," and "not mentioned." Information on publication date, source, and author(s), phosphorus bioavailability, and demineralization were also collected. RESULTS:After removing duplicates, 199 resources from Google and Yahoo and 33 from Facebook were reviewed. Resources ranged from 2005 to 2021 and were primarily authored by registered dietitians and medical doctors (65% and 31%, respectively). Dietary advice mostly focuses on restricting high-phosphorus foods and phosphorus additive-based processed foods. Dietary restrictions were generally consistent with the traditional low-phosphorus diet, which targets whole grains, dairy, and plant-based protein foods, although major inconsistencies were noted. Phosphorus bioavailability and demineralization were rarely mentioned (16% and 8%, respectively). Similar findings were found on Facebook, but the limited number of resources limited meaningful comparisons. CONCLUSION:Results showed that online resources for phosphorus-specific nutrition therapy are highly restrictive of heart-healthy food items and contain significant inconsistencies. Given the widespread and increasing use of online resources by people with CKD and health care professionals to inform dietary choices, efforts are urgently needed to establish consensus for phosphorus-specific nutrition therapy. Until then, the findings of this study provide a basis for increasing awareness of the potential for confusion arising from online resources.

OBJECTIVES/GOALS: Particulate matter (PM) and metabolic syndrome (MetSyn) increase risk of World Trade Center-Lung Injury (WTC-LI). Mediterranean-type diets have also been found to improve lung function. Fire Department of New York 1st-responders with a high PM exposure at WTC and MetSyn may have improved lung function after a Mediterranean dietary intervention. METHODS/STUDY POPULATION: Food Intake REstriction for Health OUtcome Support and Education (FIREHOUSE) randomized clinical trial (RCT) assessed our hypothesis that a low-calorie Mediterranean (LoCalMed) intervention targeting clinically relevant disease modifiers will improve metabolic risk, subclinical indicators of cardiopulmonary disease, quality of life, and lung function in firefighters with WTC-LI. Primary-outcome targeted a LoCalMed loss of BMI(≥1kg/m2). Secondary-outcomes included lung function, quality of life, and cardiovascular health. Male firefighters with WTC-LI and a BMI>27kg/m2 were randomized to: 1. LoCalMed (n=46); or 2. Usual Care (UC; n=43). Clinicaltrials.gov:NCT03581006. RESULTS/ANTICIPATED RESULTS: LoCalMed’s estimated efficacy on BMI reduction crossed the pre-specified significance boundary on interim analysis compared to UC. In addition, improvements were observed in secondary-outcomes of lung health (FEV1 and FVC), inflammation (WBC), vascular disease (DBP), quality of life (SF-36, health perception) and dietary habits (less cholesterol, carbohydrates, fats, and sweets and increased protein) in the LoCalMed arm. DISCUSSION/SIGNIFICANCE: LoCalMed significantly decreased BMI and alleviated adverse health outcomes in our WTC-exposed first responders. A fully powered RCT is required to determine if this approach is efficacious for the treatment of WTC-associated pulmonary disease, as well as LoCalMed’s generalizability to PM associated disease.

Objective: We quantified the association of overall and daytime time in range (TIR, 70-140 mg/dL) with weight change in a behavioral weight loss intervention. Methods: Data for this study came from the Personal Diet Study, a 6-month weight loss trial in adults with prediabetes or moderately controlled T2D (HbA1c<8%) involving remote behavioral counseling and dietary self-monitoring via a smartphone app. Participants wore blinded Abbott Freestyle Libre Pro CGMs for ≤2 weeks at baseline and 6 months. Based on clinically meaningful changes in two TIR metrics: “All-TIR” (all CGM readings) and “Day-TIR” (6am-midnight CGM readings), participants were categorized as “Improved” (>5%), “No Change” (-5 to 5%), or “Declined” ( Results: We analyzed baseline and 6-month CGM data from 66 participants (age 63±8 years, 62% female, 64% White, 20% African American, BMI 31.5±5.0 kg/m2, HbA1c 5.8±0.5%). When stratified by Day-TIR change, Improved had greater weight loss compared to No Change and Declined (p=0.006) (Figure 1). When stratifying using All-TIR, no significant weight change differences were observed across groups (p=0.15). Conclusion: Improved daytime TIR, but not overall TIR, was associated with greater weight loss in a behavioral weight loss intervention. Disclosure S. Barua: None. M. Mottern: None. D. St-jules: Consultant; Ardelyx, Inc. E. Segal: None. M. Bergman: None. J. O. Aleman: Advisory Panel; Intellihealth, Consultant; Novo Nordisk, Employee; Veterans Administration, Research Support; NIH - National Institutes of Health, Veterans Administration. A. Schmidt: None. M. Sevick: None. D. A. Upadhyay: None. C. Popp: None. L. Hu: None. M. Curran: None. L. Berube: None. H. Li: None. C. Wang: None. M. Pompeii: None. Funding American Heart Association (17SFRM33590133)

Phosphorus is a vital nutrient, but disturbances in phosphorus homeostasis are central to chronic kidney disease-mineral and bone disorder. To minimize disturbances, traditional dietary guidance focused on a numerical phosphorus target leading to the exclusion of many healthy foods and implementation challenges. Contemporary phosphorus guidance focuses on dietary source, avoiding additives, and emphasizing low-phosphorus bioaccessibility foods, leading to a more liberal approach. Additional work is needed to demonstrate the efficacy of these contemporary approaches and understand the influence of specific foods, processing, and cooking methods. Unfortunately, patient education using traditional and contemporary strategies may give mixed messages, particularly related to plant-based foods. Thus, greater clarity on the effects of specific foods and dietary patterns may improve phosphorus education. This review aims to discuss the evolution of dietary phosphorus management while highlighting areas for future research that can help move the field toward stronger evidence-based guidance to prevent and treat hyperphosphatemia.