Protein is the building material of our body. So while proteins are important for your body, a high-protein diet can lead to an accelerated decline in kidney function in chronic kidney disease. In this article you will find the most important topics about protein & early-stage kidney disease.
Protein - the basic building block
Proteins are the building blocks of our body. Optimal protein intake is important to avoid depleting the body's reserves. We need it, among other things, to build and maintain muscles, for immune defense and as a component of the blood. Protein is found in animal and plant foods. An adequate intake of protein is fundamentally important for your health.
Protein in case of early-stage kidney disease
Although protein is essential for your body, some studies in the past showed that a high-protein diet can promote faster progression of kidney disease to dialysis in known kidney failure stages 3 to 5 (without the need for dialysis). Scientists believe that increased protein intake may overstress the kidneys' filtering function. Different rules apply to patients with renal insufficiency requiring dialysis and after kidney transplantation. In dialysis, a high protein intake is often even important and recommended. A slightly higher protein intake can also be beneficial for diabetics. In this article you can read about the guidelines for protein intake in stages 3 to 5 of kidney failure (without the need for dialysis) and what you should look out for.
What exactly is protein?
Protein consists of several building blocks called amino acids. You can think of them like Lego bricks. Our body cannot produce some of the building blocks itself. Therefore, it needs a certain amount every day in order not to have to break down its own muscle mass for the daily required amount of protein. Since there are many different Lego building blocks, it is best to make your diet as varied as possible. This way you ensure that you are consuming a high number of different amino acids.
Which foods contain a lot of protein?
As mentioned, you can control your protein level primarily through your diet. Basically, you can say that all animal foods (e.g. fish, meat, sausage) or their products (cheese, eggs) contain a relatively high amount of high-quality protein. Vegetable foods such as cereals, bread, pasta or rice also contain protein. Fruits and vegetables, as well as fats and sugar, contain little or no protein.
What happens when there is an undersupply or oversupply?
An oversupply of protein can lead to a faster deterioration of kidney function and thus to dialysis if you already have early-stage kidney disease, as you already know. In healthy people, a high protein content in the diet is often recommended for weight regulation. This should be avoided in the case of known kidney disease and instead attention should be paid to an individual daily protein intake.
Older people with kidney disease in particular often consume too little protein. This is especially true for people on dialysis, who have an increased protein requirement. Scientists estimate that 28-54% of people on dialysis are malnourished. This is not good because when people are undersupplied, they lose muscle mass particularly quickly. This in turn leads to physical weakness. As a result, malnutrition can lead to health problems. Your doctor also calls malnutrition.
How much protein should I consume?
For people with kidney disease who do not have diabetes, are not pregnant, and are not on dialysis, a reduced protein intake may be recommended. Exactly what that means depends on your overall nutritional status, your age, and several other important aspects of your kidney disease and life circumstances. Some medical guidelines recommend a reduced protein intake of 0.55 - 0.6 g per kg body weight per day. However, this should only be recommended under close monitoring by a caring medical team and under certain conditions. These include a stable nutritional status, a healthy body weight and a stable general condition. The calories saved by such restricted protein intake should be replaced by carbohydrates and fats.
Since the recommendation of a significant restriction of protein intake may be accompanied by an increased risk of malnutrition and undersupply of important nutrients, a moderate protein intake of about 0.8 to 1.0 g per kg body weight per day is often recommended.
With a protein intake of 0.8 g/kg/day, this corresponds to a daily protein intake of 56 g for a body weight of 70 kg. Please consider these calculations as an approximate guideline. For dialysis, the recommended amount increases to 1.0 - 1.2 g per kg body weight per day. Exactly how much protein you need requires an individual recommendation from your nephrologist.
Will I feel if I am consuming too much or too little protein?
Too much protein intake can lead to high urea levels (urea is a breakdown product of protein). In addition, high protein intake can also lead to an accelerated decline in your kidney function. You can recognize this faster progression of your kidney disease by a faster decrease of your glomerular filtration rate (=GFR) in your personal laboratory values. However, this is not about an extreme decrease in your kidney function in a short period of time. Rather, we are talking about a decline in GFR over many years that can be slowed with a low-protein diet.
In the worst case, malnutrition can lead to an undersupply of important proteins. You may notice such deficiency by feeling especially tired and physically weak. Your doctor will determine malnutrition by different values. Signs may be a weight loss of more than 5% in 3 months or 10% in 6 months, a BMI below 23, or a serum albumin in the laboratory below 38 g/l.
What do I need to watch out for on a low protein diet with kidney disease?
To slow down the progression of your kidney disease and keep your kidneys healthy and fit, you should follow the upper limit for protein intake. In the Mizu app's food diary, you can keep track of your daily protein intake and view your daily guidelines.
In Mizu's food search feature, you can also look up the protein content of individual foods and check which foods are suitable for you. This way you can easily keep track of your protein intake in case of kidney disease.
So what does kidney disease mean for my diet now?
You should make sure that you keep track of your protein intake in kidney disease. The target range for chronic kidney disease without dialysis or diabetes is 0.8 - 1.0 g per kg body weight per day. In the Mizu app you will find many practical nutrition tips, examples and tricks.
