# Protein Intake Calculator

> Recommends a daily protein range in grams from body weight and goal (sedentary RDA 0.8 g/kg up to 1.6–2.2 g/kg for muscle gain or fat loss), based on the ISSN position stand.

- Calculator id: `protein-intake` · Category: Health (`health`) · Tool name: `calculate_protein_intake`
- Canonical page: https://tttkmbb.com/health/protein-intake · This document: https://tttkmbb.com/health/protein-intake.md · JSON definition: https://tttkmbb.com/health/protein-intake.json

## Purpose

Recommends a daily protein range in grams from body weight and goal (sedentary RDA 0.8 g/kg up to 1.6–2.2 g/kg for muscle gain or fat loss), based on the ISSN position stand.

**Use when:** You want a protein target in grams per day for an adult given their activity or goal.

**Do not use when:** Kidney disease or other medical conditions limit protein; consult a clinician.

## Input

| Parameter | Type | Unit | Required | Description |
| --- | --- | --- | --- | --- |
| `weight_kg` | number | kg | required | Body weight in kilograms. (> 0, max 700) |
| `goal` | enum: sedentary \| active \| endurance \| muscle_gain \| fat_loss \| older_adult |  | optional, default "active" | Determines the g/kg range applied. |

## Output

| Field | Type | Unit | Description |
| --- | --- | --- | --- |
| `protein_min_g` | number | g/day | Lower end of the range. |
| `protein_max_g` | number | g/day | Upper end of the range. |
| `protein_recommended_g` | number | g/day | Midpoint of the range. |
| `g_per_kg_range` | string |  | Grams per kilogram applied. |

## Formula

`protein_g = weight_kg × g_per_kg (range depends on goal)`

## Data Sources

- Jäger R et al. (2017) ISSN Position Stand: protein and exercise, J Int Soc Sports Nutr 14:20 — https://jissn.biomedcentral.com/articles/10.1186/s12970-017-0177-8 (peer_reviewed, retrieved 2026-09-23)
- National Academies – Dietary Reference Intakes for protein (RDA 0.8 g/kg) — https://nap.nationalacademies.org/catalog/10490 (standard, retrieved 2026-09-23)

Data freshness: `static`. Deterministic formula with fixed constants; results never go stale. Inputs supplied by the caller determine the output.

## API

- `GET https://tttkmbb.com/api/v1/calculate/protein-intake?weight_kg=…`
- `POST https://tttkmbb.com/api/v1/calculate/protein-intake` with JSON body `{"inputs": {…}}`
- Response: unified envelope (`success`, `request`, `result.values`, `result.units`, `sources`, `freshness`, `timestamp`, `next_actions`, `links`); see https://tttkmbb.com/docs/response-format.md
- Schema: https://tttkmbb.com/api/v1/calculators/protein-intake · OpenAPI operationId `calculate_protein_intake` in https://tttkmbb.com/openapi.json
- Authentication: none. Rate limit: fair use, see https://tttkmbb.com/docs/rate-limits.md.

## MCP

- Server: `https://tttkmbb.com/mcp` (Streamable HTTP, JSON-RPC 2.0, no auth)
- Tool:  `run_calculator` with `{"calculator_id": "protein-intake", "inputs": {…}}`

## Example

- 70 kg sedentary: inputs `{"weight_kg":70,"goal":"sedentary"}` → `{"protein_min_g":56,"protein_max_g":56,"protein_recommended_g":56,"g_per_kg_range":"0.8–0.8"}`
- 80 kg muscle gain: inputs `{"weight_kg":80,"goal":"muscle_gain"}` → `{"protein_min_g":128,"protein_max_g":176,"protein_recommended_g":152}`

```
GET https://tttkmbb.com/api/v1/calculate/protein-intake?weight_kg=70&goal=sedentary
```

## Limitations

Kidney disease or other medical conditions limit protein; consult a clinician. All values are computed from the formula above; no measurement or live data is involved.

## FAQ

**Can I eat too much protein?**

Healthy adults tolerate intakes up to about 2 g/kg long term; higher intakes are not harmful for healthy kidneys but bring no extra benefit.

**Should I use total or lean body weight?**

For people with obesity, using target or lean body weight avoids unrealistically high targets.

## Related

- [Macro Calculator](https://tttkmbb.com/health/macros.md) — Fit the protein target into a full macro split.
- [Lean Body Mass Calculator](https://tttkmbb.com/health/lean-body-mass.md) — Use lean mass instead of total weight for very heavy individuals.