For friends with chronic kidney disease (CKD) stages 3 to 5 and those undergoing dialysis, daily diet is by no means a trivial matter of "eating whatever you want." Scientific and rational dietary management is an important foundation for maintaining stable conditions and improving quality of life. Its core principles can be summarized in five key words: potassium control, phosphorus control, sodium control, high-quality protein, and water restriction. Eating right lightens the body's burden; eating wrong may worsen discomfort.

It should be specifically noted that "high-quality protein" is the cornerstone of the kidney failure diet, but the intake needs to be "tailored to the individual" — non-dialysis patients emphasize "high-quality low protein" to reduce the burden on the kidneys; dialysis patients need "high-quality adequate protein" to compensate for protein loss during the dialysis process.

I. Foods Recommended to Eat in Moderate Amounts

Under the premise of controlling total daily protein intake, it is recommended that more than half of the protein comes from "high-quality protein." This type of protein contains essential amino acids for the human body, has high utilization rates, and produces relatively less metabolic waste. When selecting protein sources, fish and poultry can be prioritized, followed by soybeans, and finally eggs, dairy, and livestock meat.

Specifically, you can choose moderate amounts of fish, poultry (white meat preferred), egg whites (extremely low phosphorus), and milk (recommended not to exceed 300 ml daily). Soybeans and their products (such as tofu and soy milk) are high-quality plant protein sources. Although some phosphorus in soybeans exists in the form of phytic acid, the actual phosphorus load after processing should not be underestimated. Those with poorly controlled blood phosphorus still need strict limitation and should not relax their vigilance simply because it is plant-based. Eggs and dairy are generally high in phosphorus and require appropriate control; eggs should not exceed 1 per day.

This can both reduce the metabolic burden on the kidneys and help maintain the body's basic nutritional needs.

For vegetables, it is recommended to prioritize low-potassium varieties such as winter melon, cucumber, loofah, Chinese cabbage, and zucchini. It should be reminded that even for low-potassium vegetables, it is recommended to slice and soak or blanch before cooking, which can further remove some potassium ions and make them safer to eat.

For fruits, low or moderately low potassium types such as apples, pears, strawberries, blueberries, and grapes are recommended. Grapes have relatively low potassium content and are generally safe in moderation, but still need to be counted toward the daily total potassium intake. High-water-content fruits such as watermelon must be strictly limited if edema or oliguria exists. For kidney disease patients with concurrent diabetes, fruit intake needs even more careful control.

Staple foods should be guaranteed in sufficient amounts. Low-protein staples such as wheat starch, lotus root starch, and vermicelli are more suitable for patients who need strict protein limitation; ordinary staples such as rice, noodles, and steamed buns contain high protein that is not high-quality and will increase the burden on the kidneys, so their intake should be reduced. If consumed, they must be counted toward the total daily protein intake. The purpose is to provide sufficient energy for the body and avoid protein being used as fuel due to insufficient energy. For cooking oil, vegetable oils such as olive oil and rapeseed oil are recommended, used in small amounts.

II. Foods Recommended to Eat Less or Avoid Altogether

High-potassium foods are a category that kidney failure patients need to be particularly vigilant about. Bananas, oranges, grapefruit, kiwi, potatoes, yam, taro, and various nuts generally have high potassium content and are recommended to be eaten less or avoided. In addition, vegetables such as okra, spinach, and celery have medium or relatively high potassium content; patients with high blood potassium should avoid them; if you really want to eat them, they must be thoroughly blanched and the cooking liquid discarded before small amounts are tried.

Fungi and algae (such as shiitake mushrooms, wood ear, kelp, nori, and enoki mushrooms) are typical high-potassium foods. Those with high blood potassium should strictly limit them; if consumed, they must be thoroughly blanched with the cooking liquid discarded, and can only be used in small amounts as side dishes.

High-phosphorus foods also need strict control. Animal organs and egg yolks, though high-quality protein, have high phosphorus content. Patients with hyperlipidemia or hyperphosphatemia should limit the number of egg yolks (such as within 3–4 per week) or mainly eat egg whites. Dairy products need attention to total amount, with daily intake not exceeding 300 ml. Various processed snacks, cola, and other carbonated drinks containing phosphorus additives should be avoided as much as possible because their phosphorus absorption rate is close to 100%. Concentrated soups and bone broth mainly have problems of high fat, high purine, and high sodium, with low nutritional value, so it is recommended to drink less; the truly vigilant "hidden high-phosphorus" sources are processed foods containing phosphorus additives.

High-salt and high-sodium foods will increase thirst and edema risk. It is recommended to stay away from pickled vegetables, cured products, ham, instant noodles, and dishes with large amounts of MSG and chicken essence, as well as heavy-flavor takeout food. Alcohol should be strictly limited or avoided; strong tea and coffee are recommended in moderation, avoiding overly strong or excessive amounts; spicy food depends on individual gastrointestinal tolerance — if there is no discomfort after eating, there is no need for absolute prohibition, but overly salty and oily spicy dishes should be avoided.

For high-moisture foods such as soups, porridge, and hot pot broth, extra attention is needed. High-water-content fruits such as watermelon must be strictly limited if edema or oliguria exists; non-dialysis patients with normal urine output can eat in moderation, but they must also be counted toward the daily total water intake; dialysis patients, even with normal urine output, need strict total control under the guidance of a doctor.

III. Five Practical Principles for Daily Diet

A low-salt diet is the first iron rule. The general population is recommended not to exceed 5 grams of salt daily; if combined with hypertension or impaired kidney function, it is best controlled below 5 grams, with the ideal state being below 3 grams. Once edema appears, salt intake must be strictly limited to within 3 grams, and with severe edema, a salt-free diet may even be required under medical advice to help control edema and blood pressure.

High-quality protein intake needs precise control. For non-dialysis CKD stages 3 to 5 patients, the recommended protein intake is 0.6 to 0.8 grams per kilogram of body weight per day. Among them, metabolically stable patients with good compliance can control at 0.6 grams; if compliance is poor or there is malnutrition risk, it can be appropriately relaxed to 0.8 grams. Specific plans should be formulated under the guidance of a doctor or dietitian; dialysis patients, due to protein loss during dialysis, need to increase their requirement to 1.0 to 1.2 grams per kilogram of body weight per day. In either case, plans should be formulated under the guidance of a doctor or dietitian. Do not blindly supplement with protein powder or eat large amounts of meat.

In strict control of potassium and phosphorus, especially for dialysis patients or those with moderate to severe kidney function impairment, it is recommended to develop the habit of checking food ingredients, choosing natural, less processed foods as much as possible, and reducing hidden potassium and phosphorus intake.

Water control needs to be tailored to the individual. For non-dialysis patients without edema, without heart failure, and with normal urine output, daily water intake can reference 1,500 to 1,700 ml, but weight changes must be closely monitored (weighing at the same time daily is recommended). If weight increases by more than 1 kg in a short period, or eyelid/lower limb edema appears, water intake should be immediately reduced and medical attention sought. Those with edema or oliguria need to strictly follow the "output matches intake" principle for water intake, individually adjusted under a doctor's guidance based on the previous day's urine output, insensible water loss, sweating amount, and cardiac function status. Do not self-apply fixed formulas. Dialysis patients must strictly follow doctor's orders.

Cooking methods are recommended to focus on steaming, boiling, stewing, and cold dressing, avoiding frying, grilling, and other high-oil, high-temperature methods. A light diet not only reduces sodium and fat intake but also helps protect cardiovascular health.

Conclusion

Dietary management for kidney failure patients is a fine science; there is no one-size-fits-all "universal recipe." Each person's kidney function indicators, blood potassium and phosphorus levels, urine output, and whether they are receiving dialysis are all different, so dietary plans must be individually adjusted. The above content is safe advice based on general principles, hoping to provide a reference direction for your daily diet. For specific dietary plans, please communicate fully with your attending physician or clinical dietitian, and find the most suitable plan for yourself under professional guidance. Remember: eating right versus eating wrong really makes a big difference.

Note: This article is for popular science purposes only and does not constitute any medical advice. If you feel unwell, please seek medical attention promptly.