Unit Preferences & Conversion

YuHeng provides a robust system for handling different nutritional and weight units, allowing users to track their intake in the units they are most comfortable with.

Supported Units

Energy

• kcal (Kilocalories): The default unit for energy tracking.
• kJ (Kilojoules): Commonly used in Australia, New Zealand, and parts of Europe.
• Conversion: 1 kcal ≈ 4.184 kJ

Weight

• g (Grams): The default metric unit for food weight and macronutrients.
• oz (Ounces): The imperial unit for weight.
• Conversion: 1 g ≈ 0.035274 oz

Implementation Details

The core conversion logic is centralized in lib/units.ts.

Base Units

Internally, YuHeng stores all data in base units:

• Energy: kcal
• Weight: grams

Conversions only happen during input (when saving to the database) and output (when displaying to the user).

Formatting Helpers

The system provides several helper functions for clean UI rendering:

• displayEnergy(value, unit): Returns a rounded number based on the preferred unit.
• displayWeight(value, unit): Returns a number with appropriate decimal places (1 for oz, 0 for g).
• formatEnergy / formatWeight: Returns a string with the value and unit unit suffix.

User Configuration

Users can switch their preferred units in the Settings page. Changing these settings only affects how data is displayed; existing logs in the database remain consistent because they are stored in base units.