Chronic Kidney Disease (CKD) has gradually become a major public health concern in China. According to the Chinese National Survey on the Epidemiology of Kidney Diseases, the prevalence of CKD in China stands at 10.8%.
Over the past decade, nutritional therapy such as low-protein and low-phosphorus diets has been proven to slow CKD progression and become one of the core treatments for chronic kidney disorders. Reasonably restricting certain nutrients reduces metabolic waste production and eases the burden on kidneys. This alleviates overwork of remaining nephrons and slows their deterioration.
However, clinical practice is plagued by confusing dietary questions, such as whether tofu is edible or whether fish is an irritant food, with inconsistent opinions among doctors and dietitians. To address this, national nephrology and nutrition experts spent two years drawing on the Kidney Disease Outcomes Quality Initiative (K/DOQI) guidelines from the National Kidney Foundation of the United States. Combining China’s national conditions and clinical practice, they formulated the national standard Dietary Guidelines for Chronic Kidney Disease, which clarifies scientific, operable dietary benchmarks including reference intakes of energy, protein and other nutrients, as well as methods to calculate daily food portions for CKD patients.
CKD patients shall follow two core dietary principles: long-term adherence to a low-protein diet, and flexible food substitution and selection.
Low-Protein Diet: Small Intake with High-Quality Protein
Protein in the human body undergoes constant synthesis and breakdown. After eating meat or tofu, dietary protein is digested in the stomach and intestines and split into 20 types of amino acids, which are then absorbed into the bloodstream.
A core issue in CKD nutritional management is the optimal protein intake. While some advocate limiting daily protein to less than 0.38 grams per kilogram of body weight, the national guideline recommends 0.6–0.8 g/kg body weight daily, prioritizing high-quality protein rich in essential amino acids, such as milk, eggs, lean meat, fish and chicken.
A widespread misconception claims tofu damages the kidneys, leading many doctors and patients to avoid soy products. In fact, soy protein counts as high-quality protein and does not require excessive restriction; soy food can be consumed as a substitute for meat from a purely protein perspective.
Uremic patients need to limit low-quality protein from cereals. Wheat starch is now recommended as a staple replacement for regular wheat flour and rice. During processing, nearly all protein is extracted from wheat flour, lowering its protein content from 9.9% to below 0.6%. Using wheat starch as the primary energy source reduces intake of non-essential amino acids.
Adjust Diet According to Individual Condition
Nutritional status of kidney patients strongly affects quality of life, complication risk and survival rates, yet malnutrition remains prevalent, affecting 30% to 60% of patients. Key recommendations are as follows:
1. Conduct regular nutritional screening and assessment, and adjust diet promptly to improve quality of life and long-term survival, including maintaining stable body weight, grip strength and normal laboratory indicators.
2. Prioritize high-quality protein within the daily protein limit to meet bodily protein demands and curb breakdown of bodily tissue protein. After symptoms resolve and blood urea nitrogen stabilizes for a period, protein intake may be slightly and gradually increased. Distribute daily high-quality protein evenly across three meals to maximize protein complementary effects.
3. Ensure sufficient daily energy supply, mainly from complex carbohydrates and monounsaturated vegetable oils.
4. Strictly control electrolyte intake to prevent hyperkalemia and hyperphosphatemia. Adjust salt intake based on edema and disease status to maintain electrolyte and acid-base balance. Patients with hyperkalemia shall consume fruits and vegetables cautiously; soaking or boiling produce in ample water can reduce potassium content during cooking.
Principles for Food Selection and Substitution
1. Cap total protein intake. Replace rice and wheat flour with wheat starch or other starches as staples. Source most protein from controlled portions of high-quality foods including milk, eggs and aquatic meat. Alternative low-protein staples include potatoes, sweet potatoes, lotus roots, water chestnuts, Chinese yams, taro and pumpkins.
2. Apart from quantified animal protein, limit other foods high in plant or animal protein, such as soybeans and their products, nuts and grains.
3. Most patients may freely choose fruits and vegetables, except those with hyperkalemia who must restrict high-potassium varieties including certain fruits, potatoes, potato starch and leafy greens.
4. For patients with poor appetite, add extra starch and vegetable oil during cooking to boost total calorie intake.
In addition, patients are advised to stick to suitable favorite foods, maintain moderate exercise, avoid tobacco and alcohol, and sustain a positive lifestyle. All these measures deliver significant benefits for disease control and treatment outcomes.