BulkUp / References
Scientific References
Updated June 2026 · BulkUp
BulkUp provides calorie targets, protein targets, weight gain forecasting, body composition estimates, and nutrition tracking tools. The information presented in the app is intended for educational and fitness purposes only and should not be considered medical advice.
Disclaimer: All calculations are estimates based on published research and population-level models. Individual energy expenditure, body composition, and nutritional requirements vary. Consult a qualified healthcare professional before making significant dietary or training decisions.
Food nutrition information displayed within BulkUp is derived from the following public nutrition dataset:
Nutritional values may vary by manufacturer, preparation method, serving size, and region.
BulkUp estimates resting calorie requirements using the Mifflin–St Jeor Equation, one of the most widely used predictive equations for resting energy expenditure.
Daily calorie targets are calculated using activity multipliers applied to estimated resting energy expenditure. Activity multipliers follow commonly accepted sports nutrition and exercise science guidelines.
BulkUp estimates calorie surpluses using the commonly accepted approximation that:
This approximation is used to estimate daily calorie surpluses required to support different rates of weight gain.
By default, BulkUp recommends protein intake based on approximately 1 gram of protein per pound of body weight, a guideline commonly used within strength training and physique-focused nutrition.
BulkUp uses the U.S. Navy Circumference Method for body fat estimation when body measurements are provided. This method estimates body fat percentage using body circumferences and height rather than direct body composition measurement.
When enabled, BulkUp uses data provided by Apple Health including:
These values are used to personalize calorie targets based on recorded energy expenditure.
Goal dates and projected progress estimates are mathematical forecasts based on selected weight gain rates and historical weight entries. Forecasts are estimates only and do not guarantee future outcomes.
BulkUp is a fitness and nutrition tracking application and is not a medical device. BulkUp does not diagnose, treat, cure, or prevent any disease or medical condition. Information provided by the app should not be used as a substitute for professional medical advice, diagnosis, or treatment.
