Current standard-of-care diet composed of dietary protein, fluid, sodium potassium, and phosphorus restrictions provided via monthly face-to-face sessions of 30-45 minutes over a period of 6 months, and a follow-up session after 3 months provided by the same licensed/registered dietitian. Patients will be recruited to the control arm in the same period to avoid seasonal differences.

Triceps Skinfold thickness measured using a measuring tape and a skinfold caliper Unit: mm

%Body Fat for edema-free patients assessed using Bioimpedance analysis (Maltron Bioscan) Unit: %

%Fat Free Mass for edema-free patients assessed using Bioimpedance analysis (Maltron Bioscan) Unit: %

%Total Body Water for edema-free patients assessed using Bioimpedance analysis (Maltron Bioscan) Unit: %

BUN assessed via blood test Unit: mg/dL

eGFR calculated using the Cockcroft-Gault equation = (((140 - age in years) x (weight in kg)) x 1.23) / (serum creatinine in micromol/l) Unit: mL/min/1.73m²

Serum K assessed via blood test Unit: mEq/L

Serum P assessed via blood test Unit: mg/dL

Serum CRP assessed via blood test Unit: mg/L

Serum Albumin assessed via blood test Unit: g/dL

Serum Hemoglobin assessed via blood test Unit: g/dL

Serum Hematocrit assessed via blood test Unit: %

Average size of red blood cells assessed via blood test Unit: Femtoliter (fL)

Serum Ferritin assessed via blood test Unit: ng/mL

Glycated hemoglobin (A1C) measured via blood test Unit: %

UmACR assessed via urine test Unit: mg/g creatinine

Urinary potassium excretion (spot) measured via urine test Unit: meq/L

Urinary phosphorus excretion (spot) measured via urine test Unit: mg/dL

GLIM criteria for the diagnosis of malnutrition. A participant is identified as malnourished when at least one phenotypic and one etiologic criterion is met. Phenotypic criteria include unintentional weight loss (>5% within 6 months or >10% beyond 6 months), age-specific low Body Mass Index (< 20 kg/m2 for individuals < 70 years old and < 22 kg/m2 for individuals 70 years and older), and reduced muscle mass assessed using body composition parameters to detect muscle depletion. Etiologic criteria include reduced food intake or assimilation (defined as a reduction in energy intake > 50% of requirements for over one week or any reduction lasting more than 2 weeks) and the presence of acute disease or chronic diseases related inflammation.

Score: one phenotypic criterion and one etiologic criterion, to diagnose malnutrition

The total caloric intake will be assessed using a culturally specific quantitative Food Frequency Questionnaire (FFQ) crossed-checked with 24-hour recall series (one on a weekday and one on a weekend). The estimated total caloric intake (Kcal) will then be divided by the body weight (kg) at the same time point of data collection.

Unit: Kcal/kg

The total dietary protein intake will be assessed using a culturally specific quantitative Food Frequency Questionnaire (FFQ) crossed-checked with 24-hour recall series (one on a weekday and one on a weekend). The estimated total amount of dietary proteins in grams (g) will then be divided by the dry body weight (kg) at the same time point of data collection.

Unit: g/kg

The total carbohydrate intake will be assessed using a culturally specific quantitative Food Frequency Questionnaire (FFQ) crossed-checked with 24-hour recall series (one on a weekday and one on a weekend). The estimated total amount of carbohydrate in grams (g) will then be multiplied by 4 Kcal to get the calories of carbohydrates. Afterwards, it will be divided by the total amount of calories consumed at the same time point of data collection to obtain the percentage of total intake.

Unit: percentage (%)

The total fat intake will be assessed using a culturally specific quantitative Food Frequency Questionnaire (FFQ) crossed-checked with 24-hour recall series (one on a weekday and one on a weekend). The estimated total amount of fat in grams (g) will then be multiplied by 9 Kcal to get the calories of fat. Afterwards, it will be divided by the total amount of calories consumed at the same time point of data collection to obtain the percentage of total intake.

Unit: percentage (%)

The total trans-fat intake will be assessed using a culturally specific quantitative Food Frequency Questionnaire (FFQ) crossed-checked with 24-hour recall series (one on a weekday and one on a weekend). The estimated total amount of trans-fat in grams (g) will then be multiplied by 9 Kcal to get the calories of fat. Afterwards, it will be divided by the total amount of calories consumed at the same time point of data collection to obtain the percentage of total intake.

Unit: percentage (%)

The total potassium intake will be assessed using a culturally specific quantitative Food Frequency Questionnaire (FFQ) crossed-checked with 24-hour recall series (one on a weekday and one on a weekend) and reported in grams per day.

Unit: g/d

The total phosphorus intake will be assessed using a culturally specific quantitative Food Frequency Questionnaire (FFQ) crossed-checked with 24-hour recall series (one on a weekday and one on a weekend) and reported in grams per day.

Unit: g/d

The total sodium intake will be assessed using a culturally specific quantitative Food Frequency Questionnaire (FFQ) crossed-checked with 24-hour recall series (one on a weekday and one on a weekend) and reported in grams per day.

Unit: g/d

The nutrition focused physical examination will be conducted by a licensed dietitian who will assess fat and muscle depletion, as well as the presence of edema.

Muscle strength will be measured using a handgrip strength assessment with a calibrated hand dynamometer. Participants will be seated upright with their back supported, feet flat on the floor, and their elbow flexed at a 90-degree angle. The hand dynamometer will be adjusted to fit the participant's hand size who will be instructed to squeeze the dynamometer with maximum effort for 3-5 seconds. Three measurements will be taken for each hand, with a rest period of 30 to 60 seconds and the average of the three measurements will be recorded as the final handgrip strength.

Unit: kg

Gastrointestinal symptoms will be assessed using the Birmingham IBS Symptom Questionnaire (B-IBS-Q), a validated tool for evaluating the frequency, severity, and impact of gastrointestinal symptoms. It is a self-administered questionnaire consisting of 11 items designed to assess the frequency of IBS-related symptoms, with each question having a standard response scale. Symptoms are measured based on a 6-point Likert scale (0-5) ranging from all of the time (5) to none (0) and converted to 100, with higher scores indicating more frequent IBS symptoms. The scale has 3 dimensions, including pain, constipation, and diarrhea.

Quality of life will be assessed using the EuroQOL-5D-5L (EQ-5D-5L), a widely validated and internationally recognized instrument for measuring health-related quality of life. The tool consists of two components: a descriptive system and a visual analog scale (VAS). The descriptive component includes five dimensions of health: mobility, self-care, usual activities, pain/discomfort, and anxiety/depression. Each dimension is rated on a 5-level scale, ranging from no problems to extreme problems. Participants will select the most appropriate level that reflects their current health status for each dimension. The responses are then used to generate a health state profile, which can be converted into a single index score using country-specific value sets. In addition to the descriptive system, participants will rate their overall health status using a visual analog scale (VAS), ranging from 0 (worst imaginable health) to 100 (best imaginable health).

Costs relevant to direct medical costs, direct non-medical costs, and indirect costs assessed using a resource utilization questionnaire with the patients, and calculated following the identification, measurement, and valuation steps.