A normal person requires 35 kcal/kg body weight /day. If undernourished about 500 more calories and if obese 500 less calories are adjusted from the daily requirement.
Usual adult requirement is 1g/kg /day. In case of chronic kidney disease about .8 gm/kg/day is recommended. Patients on dialysis require about 1.2 to 1.5 g/kg/day.
Proteins from animal sources are absorbed better. However there is uncertainty whether animal proteins i.e. milk, eggs, fish , meat etc are better for preserving the residual renal function in CKD patients.
In nephrotic syndrome the proteins recommended are .8g/kg/day. However daily urine losses in g/day are added to this calculation.
In case proteins are low in the blood, atherosclerosis of arteries is hastened. Cardiovascular and cerebrovascular complications are more common and life expectancy is reduced if S alb is < 3.5gm/dl. Hence if proteins are curtailed, care should be taken that the protein level in blood remains in normal range. Severe protein restriction can also lower body immunity and make a person prone to infections. These are no longer recommended. Fats: These should not form > 40 % of the caloric requirement in the body. Very low intake reduces essential fatty acids and fat soluble vitamins. Each gm of fat provides 9 kcal. Hence in 2000 kcal diet about 60-100 gm of fats /day should not be exceeded. Fats having high levels of polyunsaturated fatty acids are preferred. Sunflolwer and safflower seeds are good sources of PUFA.
Rest of the calories are made of carbohydrates. Complex carbohydrates are better than simple sugars. Simple sugars are avoided in diabetics. These increase triglyceride levels and make a person prone to obesity as well.
Vitamins & Minerals:
Salt restriction is necessary in nearly all hypertensives, patients with edema due to nephrosis , dialysis and fluid overload situations. A watch is kept over salt and water status to prevent both dehydration and overhydration. In some cases kidneys can lose excessive salt (salt losing states). Your doctor can advise you better in these situations.
In dialysis patients , water soluble vitamins may be lost during dialysis. Supplements of these are then required to replenish body resources.