An interventional study of Low-potassium, ultra-processed diet and Low-potassium, minimally processed diet in Chronic Kidney Disease, sponsored by University of Alberta. Not yet recruiting. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-10-26.
Sponsored by University of Alberta · Not applicable, Interventional, and Basic science
What is this study about?
This clinical trial is designed to learn how potassium from different types of food affects blood potassium levels and overall health in people with chronic kidney disease (CKD, stages 3B-5).
People with CKD are often advised to avoid potassium-rich foods, even though fresh fruits and vegetables are important for good health. However, potassium in processed foods (such as packaged snacks and ready-made meals) may be absorbed differently than potassium from fresh foods.
This study will compare minimally processed vs. ultra-processed foods to determine how different sources of potassium affect potassium levels and help create better dietary recommendations for people with CKD.
What are the study goals?
The study will answer:
Researchers will compare the effects of four diets to understand how low and normal-potassium rich diets from fresh vs. processed foods influence:
What will participants do?
Participants will follow four different 10-day diets over the course of the study. All food will be provided at no cost. These diets are:
There will be 16-day breaks (washout period) between diets where participants return to their normal eating habits.
During the study, participants will:
3,090 studies on the registry are indexed under Renal Insufficiency, Chronic; 698 are open to participants now.
This study's planned enrollment of 48 is below the median of 73 across 2,157 interventional studies indexed under Renal Insufficiency, Chronic.
Browse Renal Insufficiency, Chronic studies →University of Alberta is the lead sponsor of 823 studies on the registry; 169 are open to participants now.
Of its 5 completed or terminated interventional studies of FDA-regulated products, 3 (60%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
General
Kidney Function
Intervention-related Conditions
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
The New York Heart Association’s four classes of how much heart failure limits physical activity.
Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
A blood test of average blood sugar over the past two to three months, given as a percentage or in mmol/mol. 6.5% (48 mmol/mol) or more is the usual threshold for diabetes, normally confirmed by a second test.
GFR and eGFR (kidney filtering)
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
NYHA class (heart failure)
The New York Heart Association’s four classes of how much heart failure limits physical activity.
Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Autoimmune disease
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HbA1c
A blood test of average blood sugar over the past two to three months, given as a percentage or in mmol/mol. 6.5% (48 mmol/mol) or more is the usual threshold for diabetes, normally confirmed by a second test.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants in this group will follow a diet consisting of ultra-processed foods with restricted potassium content.
Other: Low-potassium, ultra-processed diet
Participants in this group will follow a diet consisting of minimally processed foods with a normal potassium content.
Other: Normal potassium-rich, minimally processed diet
Participants in this group will follow a diet consisting of ultra-processed foods with a normal potassium content.
Other: Normal potassium-rich, ultra-processed diet
Participants in this group will follow a diet consisting of minimally processed foods with restricted potassium content.
Other: Low-potassium, minimally processed diet
A diet restricted in potassium, primarily composed of industrially processed foods such as packaged snacks and processed meals.
A diet restricted in naturally occurring potassium, primarily composed of fresh fruits, vegetables, whole grains, and other minimally processed foods.
A diet with normal potassium content, primarily composed of fresh fruits, vegetables, whole grains, and other minimally processed foods, rich in naturally occurring potassium, following a Mediterranean-style pattern.
A diet with normal potassium content, primarily composed of industrially processed foods such as packaged snacks and processed meals
Fasting Serum Potassium Levels (mmol/L)
This measure assesses the concentration of potassium in participants' blood after fasting overnight. Normal potassium levels typically range from 3.5 to 5.0 mmol/L.
Time frame: Days 10, 36, 62, and 88.
Postprandial Whole-Blood Potassium Response (mmol/L)
This measure examines changes in blood potassium levels after a standardized test meal. Blood samples are collected before the meal (baseline) and at regular intervals (15, 30, 60, 90, 120, 150, and 180 minutes) to calculate the area under the curve (AUC), which reflects the total potassium response over time.
Time frame: 15, 30, 60, 90, 120, 150, 180 minutes post-meal at days 10, 36, 62, and 88.
Potassium Bioavailability
Potassium bioavailability is assessed by measuring the potassium content in 24-hour urine samples. This provides insights into how much potassium from the diet is absorbed and how much is excreted by the body.
Time frame: Days 7-9, 33-35, 59-61, 85-87.
Body Composition (kg)
This measure estimates participants' fat mass and fat-free mass. Body composition is assessed using bioelectrical impedance analysis, which uses safe, low-level electrical currents to estimate tissue and fluid distribution. Results are reported in kilograms (kg).
Time frame: Baseline and days 10, 36, 62, and 88.
Body water (L)
This measure evaluates fluid status, i which plays a role in potassium handling. Body water is estimated using bioelectrical impedance analysis, which uses safe, low-level electrical currents to estimate tissue and fluid distribution. Results are reported in liters for total, extracellular, and intracellular water.
Time frame: Baseline and days 10, 36, 62, and 88.
24h blood pressure (mmHg)
Systolic and diastolic blood pressure will be monitored for 24h.
Time frame: Days 8-10, 34-36, 60-62, and 86-88.
Dietary Satisfaction Questionnaire
Self-administered questionnaire to provide feedback on the palatability, variety, and overall acceptability of the study-provided diets.
Time frame: Days 10, 36, 62, and 88.
Hyperkalemic Events
The frequency and severity of hyperkalemic events (serum potassium ≥5.5 mmol/L) are monitored throughout the study to ensure participant safety. Hyperkalemia episodes are recorded as a count of occurrences for each dietary phase. Evaluated at screening, baseline and Day 10 of each 10-day dietary phase.
Time frame: Enrollment (Screening), baseline, and days 10, 36, 62, and 88.
Potassium Content in Foods (mg)
The potassium content of study-provided meals is measured to ensure accurate dietary potassium levels during each phase. Measured during the menu development phase and throughout the study.
Time frame: Before enrollment and through study completion, an average of 3 years
Phosphorus Content in Foods (mg)
The phosphorus content of study-provided meals is measured to ensure accurate dietary phosphorus levels during each phase.Measured during the menu development phase and throughout the study.
Time frame: Before enrollment and through study completion, an average of 3 years
Sodium Content in Foods (mg)
The sodium content of study-provided meals is measured to ensure accurate dietary sodium levels during each phase. Measured during the menu development phase and throughout the study.
Time frame: Before enrollment and through study completion, an average of 3 years
No study locations are listed for this record.
Plan to share: No — We have not yet finalized a plan for sharing individual participant data. The decision will depend on several factors, including participant consent, ethical approval, and institutional policies regarding data privacy and security. Future data sharing may be considered upon additional ethical review and participant consent.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is not yet recruiting, as verified in Oct 2026. You cannot join it, but the record below documents what was studied.
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