Renal cortical necrosis is a rare form of kidney tissue death that affects only part or all of the outer layer (cortex) of the kidney and not the inner layer (medulla). Renal cortical necrosis can occur at any age. About 10% of cases occur in infants and children. More than half of the newborns with cortical necrosis are delivered with abrupt placental separation (placental abruption); the other most common cause is bacterial infection of the blood stream (sepsis). In children, cortical necrosis can be followed by infection, dehydration, shock, or hemolytic uremic syndrome. In adults, bacterial sepsis causes cortical necrosis in approximately 1/3 of all cases. Although the accelerated etiology and prolonged anuric phase may complicate the clinical presentation, treatment is similar to other forms of acute renal failure. All appropriate methods, including maintenance dialysis, are applied to restore residual function. Some patients may regain adequate function after a few months without the need for continued maintenance dialysis. However, long-term dialysis or kidney transplantation is usually necessary. After many years of clinical experience, the consensus is that when the patient’s renal function is in the early or middle stage of impairment, i.e., when the glomerular filtration rate (GFR) is greater than about 25 ml/min, a protein intake of about 0.6 g/kg body weight per day is appropriate, and caloric supplementation is necessary. In recent years, some people also advocate supplementation with essential amino acid preparations or α-keto acid amino acid preparations. However, these preparations are more expensive, which limits their use. In the low-protein diet, high-quality protein should be the mainstay, such as milk, eggs, fish and lean meat, and the caloric energy in the diet must be sufficient. A minimum of 35 kcal per kilogram of body weight is required. How to increase the amount of high quality protein in the diet and reduce the amount of vegetable protein, nowadays, wheat starch is often used clinically as the main source of caloric energy. Corn starch and potato starch can also be used instead of rice and flour. Because of the low vegetable protein in starch, it contains 0.4 to 0.6 grams of vegetable protein per 100 grams, while flour contains 6 to 10 grams of vegetable protein per 100 grams. Clinically, plant protein will be saved to be supplemented with animal protein such as eggs, milk, lean meat, etc., so as to meet the physiological needs of the body. This can meet the caloric energy needs, on the other hand, can also correct the abnormal amino acid metabolism in the body. In addition to starch, foods containing high calories and low protein can be used in the diet as the main source of calories, such as potato, yam, taro, groundnut, lotus root, pumpkin, vermicelli, water chestnut, lotus root powder, rhizome powder, water chestnut powder, dough powder, etc. Foods containing high non-essential amino acids should be limited, such as dried beans, soy products, hard fruits and cereals, etc.