Self-Performed Dietary Sodium Reduction and Blood Pressure in Patients With Essential Hypertension: A Randomized Clinical Trial.

BACKGROUND: Hypertension is the leading risk factor for cardiovascular disease worldwide. Patients with blood pressure (BP) response to dietary sodium reduction are referred to as "salt sensitive." Salt sensitivity (SS) might be due to differences in sodium storage capacity and the erythrocyte SS examines this capacity of the red blood cells. This study aimed to test the effect of a self-performed sodium reduced diet on BP in patients with essential hypertension and examine whether erythrocyte SS predicts SS. METHODS AND RESULTS: Seventy-two patients with hypertension were included and randomized 2:1 to either sodium reduction or a control group for 4 weeks. Blood samples, 24-hour BP measurement, and 24-hour urine collection were performed before and after. The intervention group received advice on how to lower sodium intake. Urinary sodium excretion decreased 66 mmol (95% CI, -96 to -37 mmol) in the intervention group compared with the control group. Systolic 24-hour BP decreased 9 mm Hg after low-sodium diet compared with the control group (95% CI, -13 to -4 mm Hg). Similarly, the difference in reduction in diastolic BP between the groups was 5 mm Hg (95% CI, -8 to -1 mm Hg). We found no correlation between erythrocyte SS at baseline and decrease in 24-hour BP, neither systolic nor diastolic (P=0.66 and P = 0.84). CONCLUSIONS: Self-performed sodium reduction was feasible and led to decrease in 24-hour BP of 9/5 mm Hg compared with a control group. The erythrocyte SS did not correlate to the change in BP after lowering sodium intake. REGISTRATION: URL: https://clinicaltrials.gov; Unique Identifier: NCT05165823.

Dietary sodium and fluid intake in heart failure. A clinical consensus statement of the Heart Failure Association of the ESC.

Sodium and fluid restriction has traditionally been advocated in patients with heart failure (HF) due to their sodium and water avid state. However, most evidence regarding the altered sodium handling, fluid homeostasis and congestion-related signs and symptoms in patients with HF originates from untreated patient cohorts and physiological investigations. Recent data challenge the beneficial role of dietary sodium and fluid restriction in HF. Consequently, the European Society of Cardiology HF guidelines have gradually downgraded these recommendations over time, now advising for the limitation of salt intake to no more than 5 g/day in patients with HF, while contemplating fluid restriction of 1.5-2 L/day only in selected patients. Therefore, the objective of this clinical consensus statement is to provide advice on fluid and sodium intake in patients with acute and chronic HF, based on contemporary evidence and expert opinion.

An educational intervention for improving knowledge, attitude, and practice of dietary salt intake among individuals with hypertension in public sector secondary care facilities, Agra, India, 2021.

We conducted a pre-post intervention study to determine knowledge, attitude, and practice toward dietary salt intake before, immediately, and 1-month after nurse-led one-on-one counseling. We purposively selected three public health facilities in Agra, India, and enrolled all eligible hypertensive patients aged 18-60 under treatment for ≥6 months. Of the 153 patients at the 1-month follow-up, counseling improved knowledge (4% vs. 42%, p < .001), a greater prioritization of a low salt diet (34% vs. 52%, p < .001), and practice of adding less salt to the dough (48% to 41%, p < .001). The counseling intervention improved knowledge, attitude, and practice toward dietary salt intake.

Non-pharmacological interventions to reduce thirst in patients with heart failure or hemodialysis: A systematic review and meta-analysis.

BACKGROUND: Thirst is a frequent and burdening symptom in many patients, especially in patients with chronic heart failure (CHF) and/or receiving hemodialysis (HD). As drug therapies are not feasible, non-pharmacological strategies are needed to reduce thirst and thirst-related burden. OBJECTIVES: To identify non-pharmacological interventions aiming to reduce thirst in patients with CHF and/ or HD, to describe intervention components, and to evaluate the effectiveness of these interventions. METHODS: In February 2024, we completed a systematic search in MEDLINE via PubMed, Livivo, CINAHL, Cochrane Library and Web of Science. Two reviewers independently screened titles, abstracts, and full texts, performed critical appraisal and data extraction. We checked risk of bias with the checklists of the Joanna Briggs Institute and the Cochrane Risk of Bias tool and calculated meta-analyses for sufficiently homogeneous studies using fixed-effects models. RESULTS: We included 15 intervention studies applying non-pharmacological interventions including chewing gum (n = 8), low-sodium diet (n = 2), acupressure (n = 1), frozen strawberries (n = 1), fluid timetables (n = 1), ice cubes and mouthwash (n = 1), and a psychological intervention (n = 1). Sample sizes varied between 11 and 88 participants. Eleven intervention studies showed a reduction of thirst as intervention effect. Meta-analyses for chewing gum showed no significant effect on thirst using a visual analogue scale (IV: -2,32 [-10.37,5.73]; p = 0.57) or the dialysis thirst inventory (IV: -0.26 [- 1.83, 1.30]; p = 0.74). Quality of studies was moderate to low. CONCLUSION: Results indicate that various non-pharmacological interventions could be helpful to reduce thirst in patients with CHF or HD, but important uncertainty remains.

The effect of salt substitution on frequency and severity of headache: results from the SSaSS cluster-randomised controlled trial of 20,995 participants.

BACKGROUND: Headache is one of the most common neurological symptoms. Headache disorders are associated with a high global burden of disease. Prior studies indicate that short-to-medium term sodium reduction reduces headache symptom. This study evaluated the effects of long-term reduced-sodium, added-potassium salt on headache frequency and severity in rural China. METHODS: The Salt substitute and stroke study (SSaSS) was an open-label cluster-randomised trial in rural China designed to evaluate the effect of salt substitution on mortality and cardiovascular events. Participants included adults with a history of prior stroke and those aged ≥60 years with uncontrolled high blood pressure (BP). Villages were randomly assigned in a 1:1 ratio either to intervention with salt substitute (75% sodium chloride and 25% potassium chloride by mass) or to control with continued use of regular salt (100% sodium chloride). In this pre-specified analysis, between-group differences in headache frequency and severity were evaluated. The study was registered with ClinicalTrials.gov (identifier number: NCT02092090). RESULTS: A total of 20,995 participants were included in the trial (mean age 64.3 years, 51% female, mean follow-up 4.7 years). At final follow-up at the end of the study, headache outcome data including frequency and severity of headaches was available for 16,486 (98%) of 16,823 living participants. Overall, 4454/16,486 (27%) individuals reported having headache: 27.4% in the intervention group (2301/8386) vs 26.6% in the control group (2153/8100) (RR 1.04, 95% CI: 0.93, 1.16, p = 0.48). There was no difference in headache severity between intervention and control groups (p = 0.90). CONCLUSION: Long term salt substitution did not reduce the frequency or severity of headaches in this population.

Post-intervention Adherence to the New Nordic Renal Diet among patients with chronic kidney disease, stages 3 and 4.

The New Nordic Renal Diet (NNRD) is a meal pattern reduced in phosphorus, protein, and sodium for patients with moderate chronic kidney disease. The NNRD showed improvements in metabolic, and physiological outcomes after 26-weeks intervention. In the original study, participants were randomized to NNRD (n = 30), or control (habitual diet) (n = 30). The aim of this study was to explore adherence to the NNRD 3 months after cessation of intervention (follow-up). Fifty-seven participants completed the follow-up visit, which consisted of fasting blood samples and 24 h urine samples. At follow-up, there was no longer a significant reduction in 24 h urine phosphorus excretion in the NNRD group. From intervention to follow-up, 24 h urine phosphorus increased by 63 mg in the NNRD group, vs. -24.1 mg in the control group, between-group difference 87.1 mg (-10.1, 184.3, p = 0.08). Our findings show that more active intervention is needed to support adherence and maintain beneficial effects of the NNRD.

Effects of Sodium-Specific Medical Nutrition Therapy from a Registered Dietitian Nutritionist in Individuals with Chronic Kidney Disease: An Evidence Analysis Center Systematic Review and Meta-Analysis.

Dietary sodium intake can increase risk of hypertension, a leading cause of kidney failure in individuals with chronic kidney disease. The objective of this systematic review was to examine the effect of sodium-specific medical nutrition therapy provided by a registered dietitian nutritionist or international equivalent on blood pressure and urinary sodium excretion in individuals with chronic kidney disease, stages 2 through 5, receiving maintenance dialysis and posttransplant. Medline, the Cumulative Index to Nursing and Allied Health Literature, Cochrane Cochrane Central Register of Controlled Trials, and other databases were searched to identify eligible controlled trials published in the English language from January 2000 until June 2020 that addressed the research question. Risk of bias was assessed using the RoB 2.0 tool and quality of evidence was examined by outcome using the Grading of Recommendations Assessment, Development, and Evaluation method. Of the 5,642 articles identified, eight studies were included in the final analyses. Six studies targeted clients who were not dialyzed, including one with clients who were posttransplantation, and two studies with clients receiving maintenance hemodialysis. Sodium-specific medical nutrition therapy from a registered dietitian nutritionist significantly reduced clinic systolic blood pressure (mean difference -6.7, 95% CI -11.0 to -2.4 mm Hg; I2 = 51%) and diastolic blood pressure (mean difference -4.8, 95% CI, -7.1 to -2.4 mm Hg; I2 = 23%) as well as urinary sodium excretion (mean difference -67.6, 95% CI -91.6 to -43.6 mmol/day; I2 = 84.1%). Efficacy was limited to individuals who were not dialyzed, including posttransplantation, but the intervention did not significantly improve blood pressure in individuals receiving maintenance hemodialysis. Adults with chronic kidney disease should begin to work with registered dietitian nutritionist early in the course of disease to receive individualized, effective counseling to improve risk factors and, ultimately, health outcomes.

Effect of Mineral-Balanced Deep-Sea Water on Kidney Function and Renal Oxidative Stress Markers in Rats Fed a High-Salt Diet.

This study investigated the effect of mineral-balanced deep-sea water (DSW) on kidney health using an animal model of kidney injury due to a high-sodium diet. High magnesium/low sodium (HMLS) and high magnesium/high calcium (HMHC) DSW samples with different mineral contents were prepared. Sprague-Dawley rats were fed an 8% sodium chloride (NaCl) diet for four weeks to induce kidney injury, and each group was supplied with purified water or mineral water. Kidney injury was observed in the NaCl group according to increased kidney injury markers and malondialdehydes, providing evidence of oxidative stress. However, the kidney injury was repaired by the intake of mineral-balanced DSW. It was confirmed that the HMLS and HMHC groups showed improved Na+ excretion through the urine. Kidney injury markers in urine decreased and upregulation of low-density lipoprotein receptor-related protein2 mRNA expression was observed in the HMLS and HMHC groups. In addition, superoxide dismutase activity was increased in the HMHC groups. The gene expression patterns of the RNA sequencing were similar between the CON and HMLS groups. These results suggest that DSW has beneficial effects on kidney health due to the balanced magnesium and calcium levels in models of kidney injury caused by excessive sodium intake.

A High-Sodium Diet Modulates the Immune Response of Food Allergy in a Murine Model.

Mounting evidence demonstrates that a high-salt diet (HSD) not only affects hemodynamic changes but also disrupts immune homeostasis. The T helper 17 (Th17) and regulatory T cells (Tregs) are susceptible to hypersalinity. However, research on the influence of sodium on Th2-mediated food allergies remains scarce. We aimed to investigate the effect of dietary sodium on the immune response to food allergies. Mice maintained on an HSD (4% NaCl), low-salt diet (LSD; 0.4% NaCl), or control diet (CTRL; 1.0% NaCl) were orally sensitized with ovalbumin (OVA) and a cholera toxin (CT) adjuvant, and then subjected to an intragastric OVA challenge. OVA-specific immunoglobulin G (IgG), IgG1, IgG2a, and IgE antibodies were significantly higher in the HSD group than in the CTRL group (p < 0.001, p < 0.05, p < 0.01, and p < 0.05, respectively). Mice on HSD had significantly higher interleukin (IL)-4 levels than the CTRL group (p < 0.01). The IL-10 levels were significantly lower in the HSD group than in the CTRL group (p < 0.05). The serum levels of interferon-γ (IFN-γ), sodium, and chloride did not differ among the three groups. This study indicates that excessive salt intake promotes Th2 responses in a mouse model of food allergy.

Feasibility of Low-Sodium, High-Potassium Processed Foods and Their Effect on Blood Pressure in Free-Living Japanese Men: A Randomized, Double-Blind Controlled Trial.

We aimed to verify the effect of new low-sodium high-potassium seasonings and processed foods containing poly-γ-glutamic acid on blood pressure in free-living settings. To this end, we conducted a randomized, double-blind controlled trial on 187 Japanese men, aged 35-67 years, who did not use antihypertensives. Participants were randomly allocated to an intervention (n = 93) or a control group (n = 94). They were given a boxed lunch and miso soup (average Na and K content for the intervention group: 1175 and 1476 mg; for the control group: 2243 and 703 mg, respectively). Blood pressure was measured three times every morning for 1 week immediately before and during the final week of the trial. On the day before and the final day of the intervention period, 24 h urine samples were collected. After intervention, the intervention group showed a significantly stronger decrease in the urinary sodium-to-potassium ratio than the control group (p < 0.001). The mean difference in systolic blood pressure change after adjustment for baseline values between the two groups was -2.1 (95% CI: -3.6, -0.6) mmHg. Compliance between the groups was similar, suggesting successful blinding. In conclusion, the use of new seasonings and processed foods aimed at lowering blood pressure in free-living settings may be feasible and effective.

Sodium Intake and Related Diseases.

Moderation in the use of salt (sodium chloride) in food and food preparations prevents the tendency of blood pressure to increase with age, and this is documented by many studies in current literature [...].

Comparison of Salt-Related Knowledge and Behaviors Status of WeChat Users between 2019 and 2020.

In order to identify the status of salt-related knowledge and behavior of the residents who were active in WeChat software between 2019 and 2020, 10-day salt-related surveys were conducted in 2019 and 2020 based on the WeChat public platform of China Healthy Lifestyle for All Campaign. Distribution and scores of salt-related knowledge, salt reduction behavior and high-salt intake behavior between 2019 and 2020 were compared. Data of 2109 participants in 2019 and 12,732 participants in 2020 were left for analysis. Overall, 88.2% of participants in 2019 had a willingness to reduce the amount of cooking salt in their households, significantly lower than 90.2% in 2020 (p-value < 0.05). In 2019 and 2020, over 80% of the participants knew fine dried noodles contain salt, but less than 30% knew ice cream contains salt. Over 78% of participants chose 5 g or 6 g for the maximum daily salt intake of healthy adults, and about 98% of participants knew that excessive salt intake would increase the risk of hypertension in both years. The percentage of participants who used salt measuring spoons asked restaurants to use less salt, read the sodium content on the nutrition facts table, chose foods with low sodium content and regularly used low-sodium salt, were 36.1%, 45.0%, 44.1%, 40.3% and 35.8% in 2019, and the percentage increased significantly to 46.4%, 49.2%, 50.8%, 47.1% and 43.4% in 2020 (all p-value < 0.05). The percentage of people regularly eating pickled mustard tubers, salted vegetables and sauce foods or using high-salt condiments also increased from 2019 to 2020. The median of salt-related knowledge scores, salt reduction behavior scores and high-salt intake behavior scores were 11, 2, 5 points in 2019, and 10, 3, 5 points in 2020, respectively. Compared to 2019, the salt-related knowledge score was relatively lower, while the salt reduction behavior score and high-salt intake behavior score were relatively higher in 2020. Besides, the score of salt-related knowledge and behaviors differed in different gender, age and hypertension groups. The COVID-19 epidemic may have influenced the salt-related knowledge and behaviors status of WeChat users in China. Promotion and education of salt-related knowledge and online behavior intervention are still needed, particularly for male and hypertension patients in the future.

Is There Association between Altered Adrenergic System Activity and Microvascular Endothelial Dysfunction Induced by a 7-Day High Salt Intake in Young Healthy Individuals.

This study aimed to test the effect of a 7-day high-salt (HS) diet on autonomic nervous system (ANS) activity in young healthy individuals and modulation of ANS on microvascular endothelial function impairment. 47 young healthy individuals took 7-day low-salt (LS) diet (3.5 g salt/day) followed by 7-day high-salt (HS) diet (~14.7 g salt/day). ANS activity was assessed by 24-h urine catecholamine excretion and 5-min heart rate variability (HRV). Skin post-occlusive reactive hyperemia (PORH) and acetylcholine-induced dilation (AChID) were assessed by laser Doppler flowmetry (LDF). Separately, mental stress test (MST) at LS and HS condition was conducted, followed by immediate measurement of plasma metanephrines' level, 5-min HRV and LDF microvascular reactivity. Noradrenaline, metanephrine and normetanephrine level, low-frequency (LF) HRV and PORH and AChID significantly decreased following HS compared to LS. MST at HS condition tended to increase HRV LF/HF ratio. Spectral analysis of PORH signal, and AChID measurement showed that MST did not significantly affect impaired endothelium-dependent vasodilation due to HS loading. In this case, 7-day HS diet suppressed sympathetic nervous system (SNS) activity, and attenuated microvascular reactivity in salt-resistant normotensive individuals. Suppression of SNS during HS loading represents a physiological response, rather than direct pathophysiological mechanism by which HS diet affects microvascular endothelial function in young healthy individuals.

The Effects of a Low Sodium Meal Plan on Blood Pressure in Older Adults: The SOTRUE Randomized Feasibility Trial.

Reduced sodium meal plans are recommended by the Centers of Disease Control to lower blood pressure in older adults; however, this strategy has not been tested in a clinical trial. The Satter House Trial of Reduced Sodium Meals (SOTRUE) was an individual-level, double-blind, randomized controlled pilot study of adults living in a congregate living facility subsidized by the Federal Department of Housing and Urban Development (HUD). Adults over age 60 years ate 3 isocaloric meals with two snacks daily for 14 days. The meal plans differed in sodium density (<0.95 vs. >2 mg/kcal), but were equivalent in potassium and macronutrients. Seated systolic BP (SBP) was the primary outcome, while urine sodium-creatinine ratio was used to measure compliance. Twenty participants were randomized (95% women; 95% white; mean age 78 ± 8 years), beginning in 7 October 2019. Retention was 100% with the last participant ending 4 November 2019. Mean baseline SBP changed from 121 to 116 mmHg with the typical sodium diet (-5 mmHg; 95% CI: -18, 8) and from 123 to 112 mmHg with the low sodium diet (-11 mmHg; 95% CI: -15.2, -7.7). Compared to the typical sodium meal plan, the low sodium meal plan lowered SBP by 4.8 mmHg (95% CI: -14.4, 4.9; p = 0.31) and urine sodium-creatinine ratio by 36% (-36.0; 95% CI: -60.3, 3.4; p = 0.07), both non-significant. SOTRUE demonstrates the feasibility of sodium reduction in federally mandated meal plans. A longer and larger study is needed to establish the efficacy and safety of low sodium meals in older adults.

Blood Pressure Effects of Sodium Reduction: Dose-Response Meta-Analysis of Experimental Studies.

BACKGROUND: The relationship between dietary sodium intake and blood pressure (BP) has been tested in clinical trials and nonexperimental human studies, indicating a direct association. The exact shape of the dose-response relationship has been difficult to assess in clinical trials because of the lack of random-effects dose-response statistical models that can include 2-arm comparisons. METHODS: After performing a comprehensive literature search for experimental studies that investigated the BP effects of changes in dietary sodium intake, we conducted a dose-response meta-analysis using the new 1-stage cubic spline mixed-effects model. We included trials with at least 4 weeks of follow-up; 24-hour urinary sodium excretion measurements; sodium manipulation through dietary change or supplementation, or both; and measurements of systolic and diastolic BP at the beginning and end of treatment. RESULTS: We identified 85 eligible trials with sodium intake ranging from 0.4 to 7.6 g/d and follow-up from 4 weeks to 36 months. The trials were conducted in participants with hypertension (n=65), without hypertension (n=11), or a combination (n=9). Overall, the pooled data were compatible with an approximately linear relationship between achieved sodium intake and mean systolic as well as diastolic BP, with no indication of a flattening of the curve at either the lowest or highest levels of sodium exposure. Results were similar for participants with or without hypertension, but the former group showed a steeper decrease in BP after sodium reduction. Intervention duration (≥12 weeks versus 4 to 11 weeks), type of study design (parallel or crossover), use of antihypertensive medication, and participants' sex had little influence on the BP effects of sodium reduction. Additional analyses based on the BP effect of difference in sodium exposure between study arms at the end of the trial confirmed the results on the basis of achieved sodium intake. CONCLUSIONS: In this dose-response analysis of sodium reduction in clinical trials, we identified an approximately linear relationship between sodium intake and reduction in both systolic and diastolic BP across the entire range of dietary sodium exposure. Although this occurred independently of baseline BP, the effect of sodium reduction on level of BP was more pronounced in participants with a higher BP level.

Efficacy of salt reduction for managing overactive bladder symptoms: a prospective study in patients with excessive daily salt intake.

This study aimed to investigate the efficacy of salt intake restriction on overactive bladder (OAB) symptoms in patients with excessive salt intake. Patients received a brochure on nutritional guidance regarding salt intake reduction and received health education every 4 weeks for 12 weeks. Data from overactive bladder symptom score (OABSS) questionnaires and frequency volume charts (FVCs) were evaluated. The daily salt intake was estimated by determining the urinary sodium and creatinine concentrations using spot urine samples. Of the 98 patients included, 71 (72.4%) successfully restricted their daily salt intake after 12 weeks (salt restricted [R] group), while 27 (27.6%) did not (salt non-restricted [N-R] group). The scores to each OABSS question and the resulting total score improved significantly in the R group; however, the individual scores remained unchanged and the total score increased in the N-R group. The FVC data indicated improved voided volumes in the R group as compared to in the N-R group. Ultimately, 17 (23.9%) patients in the R group no longer fulfilled the OAB diagnostic criteria after salt intake reduction. Thus, salt intake reduction improved urinary symptoms in patients with OAB and may be a therapeutic option for OAB in patients with excessive daily salt intakes.

Cleavage state of γENaC in mouse and rat kidneys.

Extracellular proteases can activate the epithelial Na channel (ENaC) by cleavage of the γ subunit. Here, we investigated the cleavage state of the channel in the kidneys of mice and rats on a low-salt diet. We identified the cleaved species of channels expressed in Fisher rat thyroid cells by coexpressing the apical membrane-bound protease channel-activating protease 1 (CAP1; prostasin). To compare the peptides produced in the heterologous system with those in the mouse kidney, we treated both lysates with PNGaseF to remove N-linked glycosylation. The apparent molecular mass of the smallest COOH-terminal fragment of γENaC (52 kDa) was indistinguishable from that of the CAP1-induced species in Fisher rat thyroid cells. Similar cleaved peptides were observed in total and cell surface fractions of the rat kidney. This outcome suggests that most of the subunits at the surface have been processed by extracellular proteases. This was confirmed using nonreducing gels, in which the NH2- and COOH-terminal fragments of γENaC are linked by a disulfide bond. Under these conditions, the major cleaved form in the rat kidney had an apparent molecular mass of 56 kDa, ∼4 kDa lower than that of the full-length form, consistent with excision of a short peptide by two proteolytic events. We conclude that the most abundant γENaC species in the apical membrane of rat and mouse kidneys on a low-Na diet is the twice-cleaved, presumably activated form.NEW & NOTEWORTHY We have identified the major aldosterone-dependent cleaved form of the epithelial Na channel (ENaC) γ subunit in the kidney as a twice-cleaved peptide. This form appears to be identical in size with a subunit cleaved in vitro by the extracellular protease channel-activating protease 1 (prostasin). In the absence of reducing agents, it has an overall molecular mass less than that of the intact subunit, consistent with the excision of an inhibitory domain.

The Feasibility of Using Computrition Software for Nutrition Research-A Pilot Study.

We evaluated the feasibility of using Computrition to design and implement a low vs. typical sodium meal plan intervention for older adults. Dietitians used Computrition to design a 7-day meal plan with three caloric levels (≤1750, 2000, ≥2250 kcals/day) and two sodium densities (low = 0.9 mg/kcal; n = 11 or typical = 2 mg/kcal; n = 9). Feasibility was determined by post-hoc definitions of effectiveness, sodium compliance, palatability of diet, sustainability, and safety. Given the low number of participants in one of the three calorie groups, the higher calorie groups were combined. Thus, comparisons are between low vs. typical meal plans at two calorie levels (≤1750 or ≥2000 kcals/day). Overall, regardless of the calorie group, the meal plans created with Computrition were effective in reaching the targeted sodium density and were safe for participants. Furthermore, individuals appeared to be equally compliant and reported similar palatability across meal plans. However, one of the three criteria for the sustainability definition was not met. In conclusion, we successfully used Computrition to design low and typical sodium meal plans that were effective, compliable, and safe. Future studies of older adults in similar settings should focus on improving the palatability of the meal plans and scaling this protocol to larger studies in older adults.