Body Weight Simulator
The Body Weight Simulator, developed by
Dr. Kevin Hall’s research group, is an online tool designed for obesity
researchers and weight management professionals to better understand how diet and
exercise quantitatively contribute to weight loss and weight loss maintenance.
This information is for use in adults only and is not intended to provide personal
medical advice. NIDDK cannot provide a diagnosis or medical advice
for an individual situation. A health care provider who has examined you and knows
your medical history is the best person to provide that information. If you
have specific questions about the information presented, concerns about individual
health matters or body weight management, please consult your physician.
The Body Weight Simulator was published as part of The Lancet Series on Obesity.
Please reference this paper when publishing material using the Body Weight Simulator:
Hall KD, Sacks G, Chandramohan D, Chow CC, Wang YC, Gortmaker SL, Swinburn BA.
Quantification of the effect of energy imbalance on bodyweight.
Lancet. 2011 Aug 27;378(9793):826-37. (PMID:21872751)
Full description of the model equations can be found in the
Dynamic Mathematical Model of Body Weight Change in Adults (PDF, 244Kb)
View our brief introductory video about the Body Weight Simulator. To optimize viewing, your media player should be set to high resolution and the video should be viewed in full screen mode.
Requirements for Running the Simulator:
The first time the simulator is launched on your computer, your web browser will
request that the applet be given access to your computer. This is required so that
simulation results can be cut and pasted from the tabulated data.
The simulator requires that Java is installed to run. Please download the
The Body Weight Simulator application has been validated to run in the following
- Windows 7 operating system using IE 8.0 and 9.0, Firefox 12.0/19.0, and Google Chrome
- Windows XP PRO operating system using IE 7.0, Firefox 12.0, and Google Chrome 19.0
- Mac OS X v10.6.8 (Lion) using Firefox 12.0/18.0.2 and Safari 5.1.4/5.1.7
Mac users will find that OS X 10.7 (Lion) disables java (even the most recent version
of java) inside browsers. It's necessary to exit the browser, go to /Applications/Utilities
in the Finder and click on Java Preferences.app (or type "open -a Java\ Preferences"
in a terminal), click "Enable applet plug-in and Web Start Applications," and restart
Accessibility and Section 508 Compliance:
The National Institute of Diabetes and Digestive
and Kidney Diseases (NIDDK) and the
NIH Office for Intramural Research are committed to providing access
to all individuals - disabled or not - who are seeking information from their programs.
To provide this information, the Body Weight Simulator has been designed to conform
to Section 508 of the Rehabilitation Act
(as amended). Section 508 requires that all individuals with disabilities
(whether they are federal government employees or members of the general public)
have access to and use of information and data comparable to that provided to individuals
without disabilities, unless an undue burden would be imposed. This website has
been designed and tested for Section 508 conformance and accessibility, while acknowledging
that both may be a work-in-progress.
Persons using assistive technology may not be able to fully access graphical representations
of the Body Weight Simulator. However, all data is available and accessible in its
Any individual using assistive technology (such as a screen reader, Braille reader,
speech recognition software, etc.) who experiences difficulty in accessing information
on this site should contact Dr. Kevin Hall (NIDDK),
placing "Accessibility/Section 508 Conformance" in the subject line. The nature
of the accessibility problem and contact information should be included in any e-mail
message. If the accessibility problem involves a particular Web page, including
the URL (Web address) of the page would be helpful. A member of the
Laboratory of Biological Modeling - (LBM) staff will contact individuals
with accessibility problems as soon as possible to assist them and to provide them
the information sought.
For More Information:
If you find that you are still unable to run the Body Weight Simulator, please send
an email to
Dr. Kevin Hall (NIDDK) and indicate whether you are using a PC or a MAC,
what operating system and version, and which browser and version, and the nature
of the problem(s) you encountered.
Last Updated: 07/15/2013