More on BODYSIM
Last updated March 12, 2025
What Does BODYSIM Include? The BODYSIM package:
- Subscription access to the BODYSIM app which includes Fitness forecasting via the BODYSIM Digital Twin, Recommendations on consumption and exercise expenditure, Rx Meal Planning and food logging, Rx Workouts and resistance training tracking, 3D body scans and other biometric tracking.
- Quarterly DEXA scans at a DEXAFit location; our team will reach out to you on locations and credits.
- Monthly At-home blood tests; you will receive your kits at home. You will receive notification in the app on when to administer the test. We will share detailed instructions and help is available throughout the whole process.
- Withings Body Scan BIA scale; your Withings scale will ship directly to your home from Withings.
- Welcome to BODYSIM box, including an Escali kitchen food scale, a BODYSIM t-shirt, a BODYSIM blender bottle, and a BODYSIM heat pack to use with your at home blood tests.
Getting Started
Download and install the BODYSIM app from the Apple Store. You will log in twice to get started, once so that our app receives your email and a second time after we enable your account. If you need help, please contact support@bodysim.com.
Once you have access to BODYSIM, the app will guide you to create or enter:
- your food macro settings that will be used during the 7-14 day training period. BODYSIM will recommend short term initial macro targets in line with your goals and the metabolism of people with similar measurements and habits. This is to provide some guidance during the training period after which, you will receive your true macro targets when BODYSIM has learned your unique metabolism.
- your body weight.
- frame size measurements.
- and set a goal.
The information above will be stored in your profile and NOTE that you need to return to your profile after your DEXA scan to add your lean mass, fat mass, bone mass and body weight per the DEXA scan values.
You will also be guided to take your first 3D body scan from the app. Note that you will return to your profile after your DEXA scan to update your lean mass, fat mass, bone mass and body weight per the scan values.
BODYSIM will recommend initial macro targets in line with your goals and the metabolism of people with similar measurements and habits. This is to provide some guidance w Later, you’ll update your macro targets once BODYSIM has learned your unique metabolism.
Checklist:
- Log your first day of meals. Food logging is the cornerstone data that powers your digital twin
- Start daily weigh-ins on your Withings scale
- Ensure your fitness tracker(s) are connected to Apple Health and flowing into BODYSIM
- If you’ve logged and weighed-in in other apps before, remove any partial days or incorrect data from Apple Health
- Click on the Exercise tab to setup your workout preferences and plan your first split
- Take your first in-app 3D body scan
- Schedule your DEXA scan and take your first blood test 7-14 days after you have started logging food and weigh-ins (Look for your DEXA Scan email)
- Schedule an onboarding session with us
Routine Activities By Frequency
Daily
- Log meals
- Weigh-in
- Log resistance training workouts
Weekly
- 3D Scan (biweekly)
- Review Data Feeds
- Review meal planning
- Order groceries
- Review workout splits
Monthly
- Test Blood
- Take POMS Survey
- Review Overtraining Score
- Reset Goals & Targets
Quarterly
- Complete DEXA Scan
Expectations for Success
BODYSIM learns your metabolic and physiologic digital twin using a variety of data, including your energy consumption and energy expenditure. It is much more sophisticated than the old “calories in, calories out” method and so requires a bit of care. The following best practices will cultivate good habits for logging, weighing and tracking exercise AND will ensure you’re creating good data to train your model. You can then use BODYSIM to inquire or forecast outcomes on changes you are considering.
- BODYSIM uses logged food consumed, exercise and your body biometrics (weight, lean mass, fat mass) along with other data you may already be collecting through various activity trackers (Garmin, iPhone, Apple Watch, etc) to construct your Digital Twin.
- The Digital Twin triangulates the true signal from all your data sources and learns your metabolism’s response to food and exercise and simulates what will happen if you stay on your plan or trend if you have been operating differently than planned.
- Set everything up in Apple Health. After you get your BODYSIM app and your Withings scale, you will need to make sure all apps have access to Apple Health, this includes: BODYSIM, Withings, and fitness trackers. Note: If you have historical weight or food logging data, you should remove access to Apple Health for those apps and delete the old data from Apple Health. We mention this because this is a common snag.
- Daily food logging in BODYSIM and daily weigh ins using the Withings Body Scan. Occasional missed days are not a problem. Remember your data is your contribution to constructing your Digital Twin. You should weigh-in and log essentially all food (with macros, not just calories), at least 6 days a week, with no gaps of two or more consecutive days as a best practice. While you want to avoid skipping days, when logging food your Digital Twin can handle missing days better than incomplete days.
- You will need to log for 7-14 days for the Digital Twin to collect enough data to generate a good Fitness Forecast (aka simulation.) This Fitness Fore is the basis for goal setting and recommendations you will receive in the app.
- Weigh your food using the Escali scale provided. It gets faster with practice and we will send some tips and tricks, including what to do when eating out.
- Expect some differences between your DEXA scan and Withings for lean mass and fat mass. We use the DEXA scan as the benchmark and the daily signal from Withings to determine daily change.
- Our BODYSIM recipes used in Rx Meal Planning have an integrated shopping cart that allows you to quickly order home delivery using Wal-Mart+. The recipes are intended to take the work out of your meal planning and food logging. You are not required to use them or to use Wal-Mart+, it just makes meal planning, food logging (and shopping for that matter) easier.
- Our BODYSIM Rx Workouts are another convenience feature. Resistance training is critical to muscle gain and while an integral part of the program, totally adaptable to your needs and equipment. When you start it will take some time to watch the demonstration videos but if you have ever consumed workout videos from the internet it's not a bigger time investment than that. You are not required to use the Rx Workouts, you can build a custom plan of your own using our extensive library of exercises.
- All cardio workouts tracked in other apps and devices will come into BODYSIM automatically if you complete the Apple Health set up.
Setting and Updating Macro Targets
When you started BODYSIM, initial target macros were created based on the data you provided. Once you complete your DEXA and enter those results, a new set of macros will be recommended in the Body → Lean/Fat Mass Goal Progress → Nutrition Targets. You can accept or adjust those. The "Protein Preference" slider allocates calories to protein, then you can choose whether to add extra calories to carbs or fat. Essentially, the app is calculating your energy deficit or surplus, then you can influence how much extra you put into which macros:
The exercise calories should be an average over the course of the week. For example, if I typically burn 400-600 calories doing cardio four days/week, 350 calories doing resistance training twice a week, with one rest day, I'll keep my average around 400 calories for exercise. It's easy to accidentally overestimate exercise calories with rest days, so the average should always be a little lower than any actual exercise session.
Food Log
Log your food intake daily using BODYSIM. While occasional missed days are not a problem, try to log essentially all food 6 days a week, and try to avoid gaps of two or more consecutive days. Never log partial days–either go back later to fill them or completely delete all meals on that day.
Collecting quality data takes some time, so in the first few weeks, pay more attention to fine tuning your habits as well as monitoring your energy balance (Body → Energy Balance → Typical Energy Expenditure) and macros. While you are logging, tracking and physically training–you are also training your model. If your energy expenditure looks low, you might be accidentally under logging calories. Vice versa, if your energy expenditure looks unusually high, you could have accidentally over logged. We had an example of accidentally logging a whole jar of peanut butter, and another of repeatedly logging only 1g of olive oil rather than 1tsp.
Weight and Activity Tracker Data
We need to make sure BODYSIM gets the right data to feed into the model. We're currently using Apple Health as a hub, so the correct sources need to be syncing to Apple Health, and any defunct sources should be disabled. Here's the overview:
- Weigh-in daily using the Withings Body Scan. Ensure your Withings Scale is writing to Apple Health. Go to Apple Health → Data Access and Devices → Withings → Turn On All
- Connect BODYSIM to Apple Health. Go to Apple Health → BODYSIM → Turn On All
- Make sure your other devices, like activity and sleep trackers, are writing to Apple Health
- When you get your DEXA scan, add that information to BODYSIM by selecting More → DEXA Scans
- At the end of each week, review your past “Energy Balance Last 7 Days” in Body → Energy Balance to identify potential issues. Unusually high or low values could come from missed days of food logging or issues with activity tracking in Apple Health.
- Watch out for incorrect scale weights coming from other devices or apps such as Power Sync. Every day you skip a weigh in–Power Sync could fill in the gap with old data.