This article briefly introduces the role of diet and nutrition in the prevention and treatment of CKD. This article briefly introduces the important role of diet and nutrition in the prevention and treatment of CKD. As the saying goes, “disease enters through the mouth”, a variety of bad eating habits and lifestyle are closely related to the occurrence and development of kidney disease. Obesity, hypertension and other lifestyle-related diseases are also closely related to kidney disease. 1, water and kidney disease Insufficient water intake is not conducive to kidney regulation of water and electrolytes, easy to occur urinary tract infections and stones. Drinking large amounts of beer will increase the burden on the kidneys, if already suffering from kidney disease, and unlimited consumption of large amounts of beer, will cause uric acid deposition leading to renal tubular obstruction, resulting in kidney failure. Often people will drink instead of boiling water, and soda, cola and other carbonated beverages or coffee and other drinks contain caffeine, often leading to an increase in blood pressure, and high blood pressure is one of the important factors that damage the kidneys. 2, salt (“eat” too salty) high salt diet is an important culprit of the increased burden on the kidneys. 95% of the salt in the diet is excreted by the kidneys, excessive intake will increase the burden on the kidneys. Sodium will lead to the body’s water is not easily excreted, and further increase the burden on the kidneys, thus leading to the decline in kidney function. Eating too salty is also likely to trigger hypertension. High salt diet will cause a significant increase in urinary sodium excretion, resulting in impaired renal tubular reabsorption of calcium, an increase in urinary calcium salt saturation, and promote the formation of calcium-containing kidney stones. 3, fat (“eat” too greasy) long-term high cholesterol diet prone to hyperlipidemia, causing atherosclerosis. Increased lipids are also extremely detrimental to the kidneys: those with severe systemic atherosclerosis have more renal vascular damage and glomerular disuse. High cholesterol feed feeding test mice, can cause glomerulosclerosis; original kidney disease in rats fed high cholesterol feed for a few weeks, it will be found that the increase in urine protein, but also found that animals with high blood lipids, the pressure of the kidney unit in its body is also increased, the increased pressure will also cause damage to the kidney unit. 4, obesity Eating too sweet, too oily will not only increase the burden on the kidneys, but also trigger obesity. Obesity will lead to increased fat content of the kidney, increased weight, increased volume, glomerular hypertrophy. Obese patients are also prone to insulin resistance, which can lead to diabetes. About nearly 40% of diabetic patients will appear diabetic nephropathy. 5, hypertension hypertension can lead to small arteriosclerosis of the kidneys, resulting in glomerulosclerosis, renal function decreases. Hypertension is closely related to diet: the incidence of hypertension is 8.1% in people with greasy food; only 2.4% with a light diet. Kidney disease, the occurrence of hypertension and diet and nutrition are closely related to the development and prognosis of the disease and diet and nutrition are more closely related once suffering from a variety of kidney disease. 6, urinary stones and diet High purine food such as animal offal (pig liver, chicken kidney, lamb belly and so on) in the body metabolism produces uric acid, uric acid in the urine increases, precipitation, deposition, and finally become uric acid stones. High salt diet can cause a significant increase in urinary sodium excretion, resulting in the inhibition of calcium reabsorption by the renal tubules, which increases the amount of calcium salt saturation in the urine and promotes the formation of calcium-containing kidney stones. Excessive consumption of dairy products in adults can lead to excessive absorption of calcium, which increases urinary calcium and also predisposes to stone formation. Spinach contains a large amount of oxalic acid, which can increase the oxalic acid content in the urine when consumed in large quantities, making it easy to form calcium oxalate stones. Patients with peptic ulcers, due to long-term overdose of milk and oral alkaline drugs, can also produce stone – lacto-alkaline syndrome. The pH of the urine helps in the treatment of certain stones. In addition to medication, the acidity and alkalinity of urine can be changed by food. We should grasp the acidity and alkalinity of the diet: some food metabolites are acidic (e.g. meat, fish, eggs, cereals) and some are alkaline (e.g. milk, vegetables, fruits). 7, eat unknown sources of medicine food Bad eating habits also include improper “medicine food”, snake bile or grass fish bile and other cases of acute kidney failure is common. Many Chinese medicines contain nephrotoxic ingredients such as aristolochic acid, which will not only bring great harm to the kidneys, but some will even cause harm to the whole body. Second, the progression of chronic kidney disease is closely related to diet and nutrition Factors that affect the progression of declining renal GFR include obesity, hypertension, diabetes, etc. are all closely related to diet and lifestyle. Factors that have a poor effect on CKD treatment such as persistent proteinuria, high blood lipids, uremic toxin accumulation, metabolic acidosis and malnutrition are also related to diet and nutrition. Patients who already have renal insufficiency or renal failure can aggravate the burden on the kidneys if they still eat a large protein diet, which will eventually lead to the progression of renal disease. Large amount of proteinuria can aggravate and promote glomerular sclerosis, lead to tubulointerstitial lesions and aggravate the deterioration of renal function. Proteinuria is an important factor in the progression of renal failure in the course of any glomerular disease or other diseases. Diseases such as hypertriglyceridemia or hypercholesterolemia can contribute to the progression of kidney disease. Nutritional therapy for chronic kidney disease has been used for more than 130 years. Active and effective nutritional therapy is essential to relieve the symptoms of uremia, delay the progression of chronic kidney disease and improve the quality of life of patients, and the diet plan should be adjusted at any time according to the degree of kidney function lesions. As diabetic nephropathy progresses more rapidly, dietary treatment is even more important. III. Dietary nutritional therapy for chronic kidney disease The purpose of nutritional therapy for CKD is to delay the progression of renal failure and postpone the start of dialysis; reduce toxins in the body, alleviate patient symptoms and improve quality of life; correct various metabolic disorders and reduce complications; improve nutritional status, increase patient survival and improve patient quality of life. In the process of nutritional therapy, one should avoid entering the misunderstanding of treatment, which affects the therapeutic effect. For example, patients with chronic renal failure need to reduce protein intake in order to reduce the burden on the kidneys, so is the lower the protein the better? A normal protein diet should be about 1 gram per kilogram of body weight per day, a low protein diet is 0.6 grams per kilogram of body weight per day, and a very low protein diet is 0.3 to 0.4 grams per kilogram of body weight per day. Low protein diets and very low protein diets must be supplemented with essential amino acids or keto acid preparations to adequately maintain nutrition and ensure protein metabolism. The low protein diet is not the lower the better, but should be arranged according to the actual situation and according to the kidney function. The supply of calories must be ensured in the case of a low protein diet, and only with giving an adequate supply of calories can the protein be fully utilized. In addition amino acid (including essential amino acids) preparations can be harmful to residual kidney function, causing glomerular hyperfiltration, accelerating the destruction of kidney units and accelerating the progression of kidney disease. The incidence of malnutrition in chronic kidney disease is about 10-40% in CKD stage 3 and 4, about 18-56% in peritoneal dialysis patients, and about 70% in hemodialysis patients. Causes of malnutrition in CKD patients include non-dialysis causes (reduced dietary intake, metabolic acidosis, high catabolic substitution, endocrine dysfunction, uremic toxins, chronic inflammation, etc.) and dialysis causes (inadequate dialysis, biologic incompatibility reactions, dialysis complications, etc.). Malnutrition can decrease renal GFR and renal blood flow, which in turn affects residual renal function. Advanced malnutrition can lead to hypoproteinemia, which in turn leads to decreased blood volume and cardiac output, which in turn can be exacerbated by decreased renal function or inadequate dialysis. Malnutrition increases the rate of hospitalization, and the relative risk of death increases by 0.4 for every 1g decrease in serum albumin. Patients with concomitant malnutrition who enter dialysis will have a significantly higher mortality rate than those with good nutritional status; therefore, a reasonable diet for CKD patients is essential. Low-protein diet for CKD patients should try to increase the proportion of high-quality protein (50-70%) on the basis of limiting the total protein, while limiting the intake of vegetable protein in staple foods. Wheat starch can be used instead of some common flour and rice. High-quality protein foods include eggs, milk, lean meat (soy products, hard fruits also contain vegetable protein, but it also contains more essential amino acids, also belongs to high-quality protein). Choose foods with high caloric energy and relatively low protein content: potatoes, white potatoes, yams, taro, lotus root, pumpkin, lotus root powder, rhizome powder, etc. When eating less, you can add some sugar or vegetable oil to increase caloric energy and meet the basic needs of the body. Patients with chronic kidney disease are prone to multiple water-soluble vitamin deficiencies and deficiencies of zinc, iron, copper, selenium, magnesium and other trace elements due to insufficient intake caused by restricted eating and metabolic changes caused by impaired nephropathy, so vitamins and trace elements should be supplemented appropriately. Patients with chronic kidney disease generally have abnormal calcium and phosphorus metabolism, and often have hyperphosphatemia. It is advisable to have a low phosphorus diet, reduce the consumption of foods with high phosphorus content such as nori, egg yolk, mushrooms, crabs and peanuts, and control the phosphorus intake below 800mg/day. If the patient’s blood phosphorus is still elevated, phosphorus binding agents are often given clinically, so that phosphorus combined with the intestinal excretion can reduce blood phosphorus. The potassium supply should be adjusted according to the blood potassium level. Patients with hyperkalemia can use methods of potassium removal such as pre-boiling with water and discarding the soup in their diet, and tea and coffee should not be consumed. In advanced patients with bleeding tendency and anemia, the diet should be supplemented with iron-rich foods. Fourth, therapeutic dietary control The best treatment is prevention. As mentioned above, the prevention and control of kidney disease is concerned about the intake of salt, fat and protein, and the prevention and control of kidney disease is closely related to the prevention and control of hypertension and diabetes. The dietary management of kidney disease, hypertension and diabetes has a lot in common. The current view of “therapeutic diet control” is also clinically important for the prevention and treatment of kidney disease. The “therapeutic diet control” includes DASH (Dietary Approaches to Stop Hypertension), TLC (Therapeutic Lifestyle Changes) The “Healthy Diet” includes DASH (Dietary Approaches to Stop Hypertension), TLC (Therapeutic Lifestyle Changes), Weight Control Diet, etc. A healthy diet and lifestyle (proper diet, weight control, physical activity, alcohol restriction, smoking cessation, etc.) can prevent hypertension and kidney damage. In the NIH-funded DASH study, 459 patients (mean age 44.6 years) with moderate hypertension (systolic blood pressure below 160 mmHg, diastolic blood pressure 80-95 mmHg) were observed for 11 weeks and their diet was improved (1 additional vegetable, 1-2 fruits, 4-5 grains, low-fat dairy products, low saturated fat diet, low salt diet per day). The results showed that the DASH diet reduced systolic blood pressure by 11.4 mmHg and diastolic blood pressure by 5.5 mmHg, leading to a presumed 15% reduction in deaths from heart disease and 27% reduction in deaths due to stroke. The study also found that the DASH diet significantly reduced serum cysteine levels, cholesterol levels. TLC (therapeutic lifestyle change) includes controlling total daily calorie intake from saturated fatty foods to be less than 7%, 25-35% calories from fat, daily cholesterol intake less than 200mg, salt intake 2400mg/d, more grains, vegetables, fruits, etc. In conclusion, renal disease and diet and nutrition have a close relationship, and a reasonable diet is important to prevent and control hypertension, diabetes, obesity and other factors that aggravate renal disorders, we should fully understand the important role of a reasonable diet and nutrition program to prevent and control the progression of renal disease and guide patients to a reasonable diet to improve their nutritional status and long-term prognosis.