📦 react-daily-calorie-intake

A lightweight TypeScript/React library to calculate daily calorie needs and macronutrient splits (protein, carbs, fats) using the Mifflin-St Jeor formula and activity multipliers.

It helps you quickly estimate:

• BMR (Basal Metabolic Rate) → calories your body needs at rest
• Maintenance calories → calories needed to maintain current weight
• Adjusted calories → based on fitness goal (lose, maintain, gain)
• Macronutrient split → protein, carbs, fats in grams

Perfect for fitness apps, diet planners, or any React project that needs calorie and nutrition tracking.

🚀 Installation

npm install react-daily-calorie-intake

or

yarn add react-daily-calorie-intake

🛠 Usage in React

import React from "react";
import { calculateCalories } from "react-daily-calorie-intake";

export default function App() {
  const result = calculateCalories({
    gender: "male",
    weight_lbs: 170,     // weight in pounds
    ageYears: 25,        // age in years
    heightInches: 70,    // height in inches (5'10")
    goals: -1,           // lose 1 lb per week (-1), maintain (0), gain 1 lb per week (+1)
    activityLevel: "moderate", // sedentary, light, moderate, active, very_active
  });

  return (
    <div>
      <h2>Daily Nutrition Recommendation</h2>
      <p><strong>BMR:</strong> {result.bmr.toFixed(0)} kcal</p>
      <p><strong>Maintenance Calories:</strong> {result.maintenance.toFixed(0)} kcal</p>
      <p><strong>Target Calories:</strong> {result.adjustedCalories.toFixed(0)} kcal</p>
      <p><strong>Protein:</strong> {result.macros.protein.toFixed(0)} g</p>
      <p><strong>Carbs:</strong> {result.macros.carbs.toFixed(0)} g</p>
      <p><strong>Fat:</strong> {result.macros.fat.toFixed(0)} g</p>
    </div>
  );
}

📊 Example Output

For a 25-year-old male, 170 lbs, 5’10”, moderate activity, and goal = lose 1 lb per week:

{
  "bmr": 1800,
  "maintenance": 2790,
  "adjustedCalories": 2290,
  "macros": {
    "calories": 2290,
    "protein": 229,
    "carbs": 229,
    "fat": 51
  }
}

🧾 Input Parameters

{
  weight_lbs: 170,     // body weight in pounds
  ageYears: 25,        // age in years
  heightInches: 70,    // height in inches (5'10")
  goals: -1,           // weekly goal: lose 1 lb (-1), maintain (0), gain 1 lb (+1)
  activityLevel: "moderate" // sedentary, light, moderate, active, very_active
}

gender: "male" | "female"

weight_lbs: number

ageYears: number

heightInches: number

goals: number

• What it is: Weekly goal for weight change in pounds per week.
  • (-1) → lose 1 lb per week
  • (0) → maintain weight
  • (1) → gain 1 lb per week activityLevel: "sedentary" | "light" | "moderate" | "active" | "very_active"

| Level | Multiplier | Description | | --------------- | ---------- | ------------------------------------------------------------------------------------------------------ | | Sedentary | 1.2 | Little or no exercise, mostly sitting (desk job, minimal movement). | | Light | 1.375 | Light exercise 1–3 days/week (walking, casual activity, easy workouts). | | Moderate | 1.55 | Moderate exercise 3–5 days/week (gym, sports, cycling, active job). | | Active | 1.725 | Hard exercise 6–7 days/week or a very physical job (construction, athletes-in-training). | | Very Active | 1.9 | Intense exercise/training twice daily, or a physically demanding lifestyle (elite athletes, military). |