The Preferences panel is toggled from either the Weight2Weight:Preferences menu item (cmd,) or by clicking the [Preferences] button.

Figure 1. Preferences panel

The {Units} preference determines which units are used for calculations and display. English units are pounds and inches; Metric units are kilograms and centimeters. The units symbols are automatically updated when {Units} is selected.

Weight2Weight does not convert displayed values from one system to another. It assumes whatever values are displayed are in the units indicated. If "200" is entered as 200 pounds while English units are displayed and then "Metric" units is selected, subsequent calculations will use the "200" as 200 kilograms. Although not necessary for the calculations, the [Clear all] button can be used to clear all inputs when units are changed to avoid potential confusion.

The {Cal/day/lb} preference determines which of four methods is used for estimating the number of Calories/day required to sustain one pound of body weight in the weight and BMI calculations. "AmerHrtAssn" uses formulas from a brochure published by the American Heart Association 10-15 years ago that have sex and activity levels as variables for the calculations. "HarBenMcArd" uses the Harris-Benedict-McCardle equations with sex, activity levels, height and age as variables. "MifflinStJeor" uses the Mifflin-St Jeor equations, also with sex, activity levels, height and age as variables. "Custom" provides an option for a user-defined number of Calories/day/pound of body weight. Note that the entered custom value must be the Calories required per day per pound. Metric users must convert Calories per day per kilogram to Calories per day per pound by multiplying by 0.45359237.

See <Calculations> for more details and the specific parameters for each calculation.

The [Restore] button will restore the default values of English units, Male sex, v.Sedate activity level and "AmerHrtAssn" Cal/day/lb. The [Save] button must be clicked to store a new set of preferences, including restored default values. Stored preferences will be recalled in subsequent Weight2Weight launches.