Fever: metabolic changes, and typhoid
Fever raises BMR by about 13% for every 1 °C, breaks down protein and drains fluid. Typhoid needs a high-calorie, high-protein, low-residue, high-fluid diet.
At a glance
Worked example: energy needs in fever
A woman normally needs 2,000 kcal a day. She has typhoid with a temperature of 39 °C. How much energy does she need?
- Normal temperature = 37 °C, so the rise = 39 − 37 = 2 °C.
- BMR rises about 13% per 1 °C, so the increase = 13% × 2 = 26%.
- Extra energy = 26% of 2,000 = 0.26 × 2,000 = 520 kcal.
- Total = 2,000 + 520 = 2,520 kcal, rounded to about 2,500 kcal.
About 2,500 kcal a day (2,520 kcal before rounding). In °F, use about 7% per 1 °F rise.
Dietary principles in typhoid
| Nutrient | Recommendation | Why |
|---|---|---|
| Energy | High: add about 13% per 1 °C rise; easily digested carbohydrate (glucose, sugar, kanji, rice) | Fever raises BMR; carbohydrate spares protein |
| Protein | High: about 1-1.5 g/kg (textbook range) from milk, curd, egg, soft dal, paneer | Replaces protein lost in negative nitrogen balance |
| Fat | Moderate, in emulsified form (milk, butter, cream) | Adds energy; heavy fried fat is poorly tolerated |
| Fibre | Low residue: no whole grains, skins, seeds or raw salads | Protects the ulcerated ileum from bleeding and perforation |
| Fluid and electrolytes | 2.5-3 litres or more: ORS, tender coconut water, juices, soups, buttermilk with salt | Replaces loss from sweat and diarrhoea |
| Meal pattern and texture | Liquid to soft, bland food in small feeds every 2-3 hours | Easy on a weak appetite and inflamed gut |
Foods and a sample one-day menu (typhoid)
| Item | Details |
|---|---|
| Include | Milk, curd, buttermilk, egg, soft rice, rice kanji, idli, custard, mashed potato, boiled and strained vegetables, banana, papaya, fruit juices, glucose |
| Avoid | Whole grains, whole pulses, raw salads, fruits with skins and seeds, fried foods, chilli and spices, pickles, street food |
| 6 am | Milk with sugar or glucose |
| 8 am | Idli (3) with dal; boiled egg |
| 10 am | Sweet lime juice or tender coconut water |
| 12 noon | Soft rice with dal, mashed potato, curd |
| 3 pm | Custard or milkshake |
| 5 pm | Rice kanji with salt; banana |
| 8 pm | Curd rice; strained vegetable soup |
| 10 pm | Warm milk |
In a fever ward, record the temperature with each feed: as the fever rises, energy and fluid needs rise. Typhoid patients feel hungry in the third week, but high-fibre food must wait until the gut ulcers heal.
2 marks: “How much does BMR rise in fever?” About 13% for every 1 °C rise in body temperature (about 7% per 1 °F).
5 marks: “Explain the metabolic changes in fever.” Higher BMR, faster glycogen use, protein breakdown and negative nitrogen balance, water and salt loss, poor appetite, higher vitamin needs.
10 marks: “Discuss the dietary management of typhoid fever with a one-day menu.” Cause, symptoms and complications, metabolic changes, energy calculation, principles table (high energy, protein, fluid; low residue; bland), foods, menu.
Fever diet = H-H-H-L: High calorie, High protein, High fluid, Low residue. 13% per degree Celsius.