Model number

Program predicts how many calories you are consuming to maintain your current weight based on sex, lifestyle, age, height, number of hours of exercise per week. Projections of weight based on modification of life style, calories, and exercise.


Only undertake a weight loss program involving dieting and exercise after first consulting with your primary care physician.
This is a weight prediction program based on the revised Harris-Benedict equations. As such, it represents a "best fit" to the data of several people. It gives estimates which may or may not be reflective of your personal data.

Enter your personal data:
SEX: Choose female or male
LIFESTYLE: Your Life style determines your metabolic rate.
Sedentary (little or no exercise, desk job) metabolic_rate = 1.2;
Lightly active (light exercise/sports 1-3 days/wk) metabolic_rate = 1.374;
Moderately active (moderate exercise/sports 3-5 days/wk) metabolic_rate = 1.55;
Heavy exercise (hard exercise/sports 6-7 days/wk) metabolic_rate = 1.725;
Set_Met_Rate if you know what your metabolic rate is (between 1 and 2).

HEIGHT (in inches)
AGE (in years)
WEIGHT (current weight in pounds)
daily_cals (Calories consumed daily on average. Make an estimate. You will actually be computing the number of calories you consume on average to maintain your weight.)
exercise_hour (Estimate the number of hours you exercise each week on average)

ESTIMATE DAILY CALORIES TO MAINTAIN CURRENT WEIGHT: Go to the optimizer GUI (button, bottom left) and run the optimizer. It will estimate your average calorie intake to maintain your weight. (The number will be in scientific notation: 2.171E3 = 2173.)

PREDICT WEIGHT LOSS BY REDUCING DAILY CALORIES: Go to Loops and run loops. It will give you your predicted weight as the number of daily calories is decreased.

PREDICT WEIGHT LOSS BY LIFESTYLE CHANGES: Enter a new values for daily calories and lifestyle, and exercise hours per week. Go to the Run Time page and run the model.

SENSIBLE WEIGHT LOSS: ONE POUND PER WEEK: A reasonable and health weight loss rate is one pound per week. Go back to the optimizer. Under Data Curves, uncheck the first box and check the box below it. The amount of calories you need to consume for a one pound/week weight loss over the course of your weight loss will be calculated.

WEIGHT LOSS MAINTENANCE: For WEIGHT enter your goal weight and LIFESTYLE changes you intend to keep doing. Enter a new goal weight which is WEIGHT-10 pounds. Go to the optimizer page, and under data curves, check the first box, and uncheck the second box. Run the optimizer. This will give you the daily calorie level you need to sustain your weight loss.

BASAL METABOLIC RATE IS BASED ON THE REVISED HARRIS BENEDICT EQUATION Muller B, Merk S, Burgi U, Diem P. Calculating the basal metabolic rate and severe and morbid obesity Schweiz Rundsch Med Prax 2001 Nov 8;90(45):1955-63 Article in German

Calories used per hour in exercise: See applet at

Basal Energy Expenditure using original Harris-Benedict equations:
See applet at

For additional background material and applets, see



The equations for this model may be viewed by running the JSim model applet and clicking on the Source tab at the bottom left of JSim's Run Time graphical user interface. The equations are written in JSim's Mathematical Modeling Language (MML). See the Introduction to MML and the MML Reference Manual. Additional documentation for MML can be found by using the search option at the Physiome home page.

Download JSim model project file

 - Help running a JSim model.

Harris J, Benedict F. A biometric study of basal metabolism in man. 
Washington D.C. Carnegie Institute of Washington. 1919.

Muller B, Merk S, Burgi U, Diem P., Calculating the basal metabolic rate 
and severe and morbid obesity. Praxis (Bern 1994). 2001 Nov 8;90(45):1955-63.

Please cite in any publication for which this software is used and send one reprint to the address given below:
The National Simulation Resource, Director J. B. Bassingthwaighte, Department of Bioengineering, University of Washington, Seattle WA 98195-5061.

Model development and archiving support at provided by the following grants: NIH U01HL122199 Analyzing the Cardiac Power Grid, 09/15/2015 - 05/31/2020, NIH/NIBIB BE08407 Software Integration, JSim and SBW 6/1/09-5/31/13; NIH/NHLBI T15 HL88516-01 Modeling for Heart, Lung and Blood: From Cell to Organ, 4/1/07-3/31/11; NSF BES-0506477 Adaptive Multi-Scale Model Simulation, 8/15/05-7/31/08; NIH/NHLBI R01 HL073598 Core 3: 3D Imaging and Computer Modeling of the Respiratory Tract, 9/1/04-8/31/09; as well as prior support from NIH/NCRR P41 RR01243 Simulation Resource in Circulatory Mass Transport and Exchange, 12/1/1980-11/30/01 and NIH/NIBIB R01 EB001973 JSim: A Simulation Analysis Platform, 3/1/02-2/28/07.