Diet in acute nephritis and nephrotic syndrome
Acute nephritis needs less protein, salt and fluid while urine is scanty; nephrotic syndrome needs normal protein, low salt and low saturated fat.
Aim and principles of the diet
Aim: To plan, prepare and calculate a diet for a young woman with nephrotic syndrome, and to show how it changes for acute nephritis. Acute glomerulonephritis (acute nephritis) often follows a streptococcal throat or skin infection, mostly in children. The inflamed glomeruli filter poorly, so there is oedema, high blood pressure, blood in urine and scanty urine (oliguria), and blood urea rises. Diet: energy adequate (about 35 kcal/kg) from carbohydrate and fat; protein about 0.5-0.6 g/kg while urea is high and urine is scanty, raised as the kidney recovers; sodium restricted (no added salt) while there is oedema or high BP; potassium restricted while urine is scanty; fluid = previous day's urine output + 500 mL for insensible loss. Nephrotic syndrome is a leak of protein through the glomeruli: heavy proteinuria, low serum albumin, generalised oedema and high cholesterol. Diet: energy about 35 kcal/kg so protein is not burnt; protein 0.8-1.0 g/kg, with a good share of high biological value (milk, curd, egg white). Some older textbooks advise a high-protein diet, but current guidance (KDIGO 2021; Krause) prefers 0.8-1.0 g/kg because extra protein mainly increases the protein lost in urine. Sodium below 2 g a day controls oedema; saturated fat and cholesterol are low because blood lipids are high; fluid is limited only if oedema is severe.
Nutrient prescription: acute nephritis compared with Ms. N's nephrotic syndrome (IBW 54 kg)
| Nutrient | Acute nephritis (oliguric adult) | Nephrotic syndrome (Ms. N) | Basis and source |
|---|---|---|---|
| Energy | About 1900 kcal (35 kcal/kg) | About 1900 kcal (35 kcal/kg × 54 = 1890) | Spares protein (Krause; Srilakshmi) |
| Protein | About 27-32 g (0.5-0.6 g/kg) while urea is high | About 54 g (1.0 g/kg), with a good share of high biological value | Nephritis: Indian texts. Nephrotic: KDIGO 2021 and Krause, 0.8-1.0 g/kg |
| Sodium | No added salt (about 1-2 g sodium) | Below 2 g sodium (about 5 g salt) | Controls oedema and BP |
| Potassium | Restricted while urine is scanty | Usually normal | Guided by serum potassium |
| Fluid | Previous day's urine + 500 mL (400 + 500 = 900 mL) | Not restricted unless oedema is severe | About 500 mL is lost through skin and breath |
| Fat and cholesterol | Normal | Below 30% of energy; saturated fat below 7%; cholesterol below 200 mg | Saturated fat and cholesterol: NCEP ATP III TLC limits; total fat below 30% is the usual textbook advice |
Foods to include and avoid (nephrotic syndrome)
| Food group | Include | Avoid |
|---|---|---|
| Cereals | Rice, idli without salt in the batter, chapati without salt, rice flakes, sago | Bread, biscuits and bakery items (salt and baking soda) |
| Protein foods | Measured milk, curd, egg white, moong dal | Egg yolk in excess, mutton, organ meats, salted dried fish |
| Vegetables and fruits | Fresh vegetables and fruits (limit high-potassium ones in nephritis) | Pickled or canned vegetables |
| Fats | Measured vegetable oils in rotation (groundnut, rice bran, mustard, sunflower) | Ghee, butter, vanaspati, fried foods |
| Seasoning | Lemon, tamarind, herbs, garlic, pepper | Table salt, pickles, papad, chips, sauces, ready-to-eat mixes |
Sample one-day menu: nephrotic syndrome (Ms. N)
| Time | Menu | Approx. amount (raw) |
|---|---|---|
| 6.00 am | Tea | Toned milk 100 mL, sugar 5 g |
| 8.00 am | Idli (3), no salt in the batter, with coriander-mint chutney | Rice 60 g + urad dal 15 g; herbs 20 g, oil 2 g |
| 11.00 am | Apple | 100 g |
| 1.00 pm | Rice, moong dal, vegetable poriyal, unsalted spiced buttermilk | Rice 100 g; moong dal 20 g; vegetables 100 g, oil 6 g; buttermilk 150 mL |
| 4.00 pm | Tea with sweet aval | Toned milk 100 mL, sugar 5 g; rice flakes 50 g, jaggery 10 g |
| 8.00 pm | Chapati (3, no salt), egg-white curry, vegetable | Atta 75 g, oil 3 g; 2 egg whites, vegetables 50 g, oil 4 g; vegetables 100 g, oil 3 g |
| 9.30 pm | Sago kheer | Toned milk 100 mL, sago 30 g, sugar 10 g |
Worked calculation: Ms. N's nephrotic diet, and the nephritis changes
Ms. N, 30 years, 160 cm, weighs 62 kg with oedema (usual weight 55 kg). She has nephrotic syndrome with normal kidney function. Find her IBW, energy and protein needs and check the menu. Then show the changes for acute nephritis with 400 mL urine a day.
- IBW = (160 − 100) × 0.9 = 54 kg (use IBW, because the oedema adds water weight).
- Energy = 54 kg × 35 kcal/kg = 1890, about 1900 kcal.
- Protein = 54 kg × 1.0 g/kg = 54 g (KDIGO 2021 and Krause: 0.8-1.0 g/kg); about a third of it comes from milk, buttermilk and egg white.
- Approximate values used (kcal and g protein per 100 g raw unless stated; rounded from Indian food composition tables, mainly IFCT 2017 and the older Nutritive Value of Indian Foods; a few, such as toned milk, are estimates): toned milk 60 and 3 per 100 mL; sugar 400; rice 355 and 8; urad dal 325 and 23; mixed vegetables 30 and 1.5; oil/ghee 900; apple 60 and 0.3; moong dal 325 and 24; buttermilk 15 and 0.8 per 100 mL; rice flakes 350 and 7; jaggery 380 and 0.4; atta 320 and 10.5; egg white 17 kcal and 3.5 g per piece; sago 350 and 0.2.
- Cereals (rice 160 g, rice flakes 50 g, atta 75 g, sago 30 g): 1088.0 kcal, 24.2 g protein.
- Pulses (urad dal 15 g, moong dal 20 g): 113.8 kcal, 8.3 g protein.
- Milk and milk products (toned milk 300 mL, buttermilk 150 mL): 202.5 kcal, 10.2 g protein.
- Egg white (2 egg whites): 34.0 kcal, 7.0 g protein.
- Vegetables (mixed vegetables 270 g): 81.0 kcal, 4.1 g protein.
- Fruits (apple 100 g): 60.0 kcal, 0.3 g protein.
- Oil and ghee (oil/ghee 18 g): 162.0 kcal.
- Sugar (sugar 20 g, jaggery 10 g): 118.0 kcal.
- Energy = 1088.0 + 113.8 + 202.5 + 34.0 + 81.0 + 60.0 + 162.0 + 118.0 = 1859.3 kcal.
- Protein = 24.2 + 8.3 + 10.2 + 7.0 + 4.1 + 0.3 = 54.1 g.
- Compare with the prescription: energy 1859.3 ÷ 1900 × 100 = 98%; protein 54.1 ÷ 54 × 100 = 100%.
- Acute nephritis with 400 mL urine: protein = 54 × 0.5 = 27 g to 54 × 0.6 = 32 g. Cereals alone give about 24 g in this menu, so the dal, egg white, buttermilk and two cups of milk are removed and the chapati is replaced by rice and sago dishes. This brings protein to about 31 g, inside the 27-32 g range; extra sugar and oil keep energy near 1900 kcal.
- Fluid for nephritis = previous day's urine + 500 mL = 400 + 500 = 900 mL, counting milk, tea, buttermilk and kheer.
- Each group is rounded to one decimal and the totals are the sums of those rounded figures; all values are approximate.
Nephrotic syndrome: about 1900 kcal and 54 g protein prescribed; the menu gives about 1859 kcal (98%) and 54 g protein (100%) with no added salt. Acute nephritis: protein about 27-32 g and fluid 900 mL.
Preparation and serving tips, and result
- Cook the patient's food in a separate pot without salt; use only the measured salt for the day (about 3 g) if the doctor allows it.
- Make unsalted food tasty with lemon, tamarind, garlic, ginger and curry leaves.
- Weigh the patient daily: a quick gain means fluid is building up.
- For nephritis keep a fluid chart; every cup of water, milk, tea, soup and kheer counts in the allowance.
- Result: The nephrotic diet gives about 1859 kcal and 54 g protein with no added salt, meeting Ms. N's prescription; for acute nephritis protein falls to about 27-32 g and fluid to 900 mL.
In the diet kitchen, renal trays are cooked salt-free in separate vessels, with a small measured salt sachet only if allowed. For acute nephritis the kitchen follows the fluid allowance written each morning from the previous day's urine output, so soup, milk and tea are counted in it.
Short answer: “How is the fluid allowance calculated in acute nephritis?” Previous day's urine output + 500 mL for insensible loss; e.g. 400 mL urine gives 900 mL fluid.
Short answer: “Why is a very high-protein diet not advised in nephrotic syndrome?” Extra protein mainly increases protein loss in urine and strains the kidney; 0.8-1.0 g/kg of good-quality protein with enough energy is advised.
Structured question: “Compare the diet in acute nephritis and nephrotic syndrome.” Energy about 35 kcal/kg in both. Protein: nephritis 0.5-0.6 g/kg while urea is high; nephrotic 0.8-1.0 g/kg, high biological value. Sodium: restricted in both (below 2 g). Potassium: restricted in oliguric nephritis. Fluid: urine + 500 mL in nephritis; not restricted in nephrotic unless severe oedema. Fat: low saturated fat and cholesterol in nephrotic syndrome.
Nephr-ITIS = Inflamed: cut protein, salt and fluid. Nephrotic = protein leaks out: keep protein normal, cut salt and saturated fat.