For many people, the time after a kidney transplant means much more normality in everyday life compared to the time on dialysis. In this article, you will find out what changes you will have to make to your diet and what will remain unchanged in return.
With a new kidney, many people who were previously on dialysis feel that they can regain some normality in their daily rhythm of life. A rhythm that, during dialysis, is largely dictated by a rigid therapy schedule. As soon as your transplant has fully taken up its function, the daily or several times weekly dialysis therapies are no longer necessary. In this context, nutrition restrictions, which were likely quite tricky previously, can also relax. Let's now look at the core differences compared to the time on dialysis. Please note that the guidelines in this article are only general guidelines. Your medical team knows your personal health situation best and you should of course always follow their recommendations.
Potassium & Phosphate
If you've been on dialysis before, you've most likely mastered the principles of low phosphate and low potassium diets. During dialysis, this is especially important: when the kidneys (almost) stop working, they also fail to excrete enough potassium and phosphate through the urine. As a result, the potassium and phosphate balance in the blood can become unbalanced.
Excessive potassium and phosphate levels in particular can cause challenges for the medical team treating the patient. These two electrolytes can only be removed from the body during dialysis. That is why it is so important during this time to support the process by not taking in too much potassium and phosphate through food. The basic goal is to keep the amount of potassium in the blood within the normal range. This ranges for potassium between 3.5 and 5.0 mmol/L. For phosphate it is often more difficult and therefore the goal is to bring the value as close as possible to the reference range. This lies in the blood between 0.84 and 1.45 mmol/L.
What changes after transplantation?
As a rough upper limit, a maximum intake of 3,000 mg of potassium per day and a maximum of 800 to 1,000 mg of phosphate per day is recommended for people on dialysis. The strict guideline values for potassium are often no longer relevant after transplantation. However, you can keep in mind which foods contain particularly high amounts of potassium and phosphate. Accordingly, you should only treat yourself to a soft drink on very special occasions, for example. But you probably know yourself that soft drinks are not healthy - regardless of your kidney.
For people with a transplant, the same rules regarding potassium and phosphate apply as for people with healthy kidneys. For potassium, the recommended daily maximum is 4,700 mg, and for phosphate, less than 1,000 mg.
The exact guideline values vary somewhat depending on the source. Unless your transplant team recommends otherwise, it is much more important to maintain a generally balanced diet.
You may experience low phosphate levels in your blood after transplantation. In this case, your transplant team may even prescribe tablets with extra phosphate.
On the other hand, if you experience high levels of phosphate or potassium in your blood, your transplant team may recommend at temporary restrictions, as during dialysis.
Your medical team will continue to monitor your potassium and phosphate blood levels regularly. This will ensure that your electrolyte levels remain in the normal range. If there are any big outliers, you may need to pay a little more attention to what you eat again. Your transplant team should tell you about this if needed. However, as long as your kidney is doing a great job, it shouldn't come to that.
In the following table you will find a short summary of the possible target ranges in case of a potassium and/or phosphate reduced diet:
Proteins
Proteins are an important source of energy in the diet. Since proteins are often lost from the body during dialysis, the protein requirement is significantly higher during this time. At least 1.2 g of protein per kilogram of ideal weight per day. Proteins are essential for many bodily functions - especially for your muscles, your immune system, and your wound healing. To ensure that these systems continue to function properly despite the increased protein loss during dialysis, it is important to consume more protein during this time.
What changes after the transplant?
With the new kidney, the energy- and protein-consuming dialysis treatments are finally over and the new kidney hopefully quickly takes over the task of the body's own janitor again.
As mentioned above, proteins are also particularly important in wound healing. Therefore, it probably comes as no surprise to you that you should also not skimp on protein in your diet for the first 4 weeks after the transplant. During this time, as much as 1.4 g of protein per kilogram of your ideal weight per day or more may be recommended. Afterwards, a daily protein intake of about 1 g per kilogram of ideal weight can be recommended.
In general, the exact daily guidelines are less important than a balanced and healthy diet (Mediterranean diet is the most common example). Now in this article the word "ideal weight" has been mentioned many times. This is especially relevant if you are particularly overweight or underweight (underweight: BMI <16; overweight >30 kg/m²). Your ideal weight if you identify as male is calculated as 50,0 kg + 2,3 kg for all 2,5 cm over 152,4 cm and if you identify as female as 45,5 kg + 2,3 kg for all 2,5 cm over 152,4 cm height.
Here is a small calculation example for the ideal weight of a woman with a height of 160 cm:
160 cm - 152.4 cm = 7.6 cm
7.6 cm / 2.5 = 3.04
3.04 x 2.3 kg = 6.992 kg -> approx. 7 kg
45.5 kg + 7 kg = 52.5 kg ideal weight
As always, it is best to talk to your treating medical team to get a personal recommendation for your diet. All information about protein intake is summarized in the following table:
Energy requirements
The amount of energy found in your food is expressed in calories (e.g. kilocalories =kcal). How much energy your body uses during the day depends on many different things. For example, it depends on your biological sex. It also makes a difference whether you spend a lot of time on the couch or do endurance sports. The time spent on dialysis is also usually accompanied by increased energy consumption. Here, the rule of thumb is to consume about 25 to 35 kcal per kilogram of ideal weight per day.
What changes after the transplant?
As a rule, you can stick to the same guideline of 25 to 35 kcal per kilogram of ideal weight in the first weeks after transplantation and in the longer term. If you are underweight, your nutritionist (specialized in kidney transplantation) may recommend a little more calories per day. If you are overweight, the opposite is true, of course.
In general, after kidney transplantation the same guidelines of approx. 25 to 35 kcal per kilogram of body weight per day apply again, which you already know from your time on dialysis. Of course, it is important for your health that your body weight is in the green zone. But your new kidney also benefits from a healthy weight. Studies have even found that the new kidney often functions longer in people with a normal weight than in overweight people. If you are not yet at your ideal weight, your recommended energy intake will be more in the range of 25 kcal per kilogram of body weight per day. If you are underweight, 35 kcal per kilogram of ideal weight or more may be recommended. However, as always, it is best to find out your personal target values from your medical team.
The following table summarizes the most important information:
Drinking amount
You probably still have the voice of your attending physician in your ear, instructing you to not drink too much. During your time on dialysis, the excess water in your body is primarily removed during dialysis treatments. To prevent too much water from accumulating in the body between therapies, it is important not to drink too much. The personal drinking quantity is based primarily on the amount of urine produced daily. The basic rule of thumb is to drink about 500 mL more than you produce urine.
What changes after the transplant?
The new kidney is there, and as soon as it has developed its full function, it will also produce urine diligently again. As a rule, the restriction on the amount of urine that can be drunk is lifted quite quickly. From now on, the same rules apply again as for people with healthy kidneys. As a rule, you can drink at least 1.5 to 2 liters (preferably water, of course) a day. It is best to drink as much as your thirst dictates and make sure that you do not go below 1.5 L per day. However, as always, your medical team has the final say.
Low-bacteria diet
One new aspect of your diet that is very different from your time on dialysis is the low-bacteria diet. In order for your new kidney to arrive relaxed in your body and do a good job, you have to take so-called immunosuppressants. These are drugs that reduce your body's own defense system (=immune system) so that it does not identify your new kidney as a foreign body and in the worst case, reject it.
These drugs are essential for the survival of your new kidney. But as always, there are pros and cons. When your immune system is shut down to protect your new kidney, pathogens like viruses, bacteria and fungi have an easier time getting into your body. Because these germs can hide on food and nutrition, there are a few rules you should follow after your transplant. These "rules" are collectively known as a bacteria-free diet. But don't worry - with a few tips and tricks, you can master even this challenge. Since this is a very important topic, you will find a separate article on the topic of "low-bacteria diet" in the Mizu app.
What remains the same?
Now you already know the most important changes regarding your diet after transplantation compared to the time on dialysis. But there are also one or two things that don't change.
You should continue to eat a healthy and balanced diet. In terms of the health of your new kidney, the Mediterranean diet is recommended. Key ingredients are fish instead of meat, lots of fruits and vegetables, and plant fats instead of animal fats. As already discussed, you don't have to pay as much attention to phosphate and potassium levels here now.
Since the Mediterranean diet is also based on preparing the dishes yourself, you literally have the amount of salt in your own hands. You are probably familiar with a low-salt diet from your time on dialysis. Specifically, this involves the electrolyte sodium, which is contained in table salt. The sodium level in your blood is also normally regulated by your kidney. Before the transplant, dialysis also took care of this. The recommendation of a maximum of 2.3 mg sodium per day also applies to kidney-healthy people and therefore also to you after transplantation. These 2.3 mg of sodium correspond to about 6 g of salt, which is also your maximum daily requirement. This means that in this case you do not have to change your diet at all. You can continue to add pizzazz to your meals with herbs and spices. If you do that, you will automatically need less salt. And you won't fall for hidden sugars in convenience foods when you cook for yourself either.
If you want to know even more about the Mediterranean diet, check out the other blog articles on this topic in the Mizu app.
How do I keep track of my diet?
Do you already know about the food diary in the Mizu App? There you can continue to enter your individual daily target values - for example for phosphate, potassium, and sodium - even after the transplant. You can also document what you eat during the day. The system automatically shows you how much of your daily target value is covered by the corresponding meal. This way you can always keep track. And now have fun eating and drinking!
