BodyEngineTM is an online app that integrates cutting-edge software with proven fitness and nutritional science to monitor your fitness state and prepare an accurate diet and activity plan to help you reach a desired goal weight. Unlike other fitness and diet solutions, BodyEngine offers highly personalized features based on your age, gender, height, current weight and activity level. BodyEngine's innovative visual interface presents a unique experience that is both fun and effective and will help you to finally achieve your desired weight at your own pace.

  • FAQ
    • Get answers to the most frequently asked questions
  • Quick start guide
    • Read the easy step-by-step instructions for how to start using BodyEngine right away
  • Evaluate your fitness state
    • Find out if your Body Mass Index (BMI) is Underweight, Healthy, Overweight, or Obese
  • Set safe and feasible goals
    • Choose the desired weight
    • Set the date when to reach your goal
    • Control the pace at which to lose weight
  • See your personalized fitness plan to reach your goal
    • Consume a constant number of calories daily
    • See the calories you need to cut from your diet
  • Leverage the power of Social Networking
    • Share your fitness goal with your Friends on Facebook
    • Lose weight with the support and encouragement of your family and friends


Is BodyEngine free?

BodyEngine is completely free for personal use. If you find BodyEngine helpful and would like to support future improvement we would appreciate your financial donation. If you are interested in using BodyEngine for commercial use, please contact us for more information.

Is the information presented by BodyEngine accurate and reliable?

Yes. The logic of BodyEngine is largely based on equations provided in the U.S. DRI (Dietary Reference Intakes) from National Academy of Sciences, which is considered the official standard for nutritional and dietary guidelines in the USA and Canada. The calculations cover multiple factors such as resting metabolic rate (RMR), estimated energy requirements (EER), fat mass to fat-free mass ratio (FM/FFM), physical activity (PA) coefficients, etc.

Is BodyEngine better than other fitness applications?

BodyEngine is different. The goal of the application is not only to provide solid and accurate numbers, but also to hide the vast complexity of scientific fitness calculations behind an intuitive and convenient user interface where all controls and tools are readily available at a fingertip.

Does BodyEngine share my personal information?

BodyEngine does not collect, store, or share any of your information.

How do I set my current and goal weight?

You can set your weight by dragging and dropping the current and goal weight sliders shown on the weight chart.

How do I adjust the number of calories I need to consume every day?

Your daily caloric intake is determined based on your age, gender, height, activity level, and you goal weight. If you want to lower or increase the number of calories, move your goal weight and goal date on the chart until the desired calories limit is shown on your Daily Calories plate.

Does BodyEngine limit my diet choices to specific predefined meal plans or nutritional products?

Not at all. BodyEngine informs you how much you should eat based on your fitness state, while you are free to include any meals you like as long as the combined number of calories per day does not exceed the level recommended by BodyEngine.

Why did my goal weight change by itself?

If BodyEngine determines that your goal weight is not achievable in a safe way based on your current weight and activity level, it will automatically adjust the goal weight to the closest weight that is supported, safe, and feasible. In this case, you will notice that the goal weight label will be marked with the word "Limit". You can read more about the achievable goals here.

Can BodyEngine help me to gain weight instead of losing or maintaining my current weight?

The highest number of calories displayed by BodyEngine is what is required to maintain your current weight. If you wish to "bulk up" and increase your weight a little (for example if you are a bodybuilder) you can consume a diet consisting of more calories than what BodyEngine recommends. After you have gained enough weight you can adjust your fitness goal in BodyEngine such that to either maintain your new weight or to reduce it a little down to a desired level.

What is BMI and how does BodyEngine measure it?

Body Mass Index is a standard measurement index of human body weight in relation to height. BodyEngine measures your current and goal BMI scores to assign your body weight into one of the five weight level categories: Underweight, Healthy, Overweight, Obese or Morbidly Obese. You can see your exact BMI scores on the fitness plan window.

Using BodyEngine

Use this section to learn about the recommended steps to follow when using BodyEngine.

Figure 1: Main window of BodyEngine

After launching the app, follow the steps indicated in Figure 1 to:

  1. Verify your personal information
  2. Update your current weight
  3. Set your fitness goal
  4. Set your activity level
  5. Check your daily calories
  6. Follow your fitness plan

1. Verify Your Personal Information

Make sure that your personal information is correct. If it is not correct, click the Update button and provide the correct information.

2. Update Your Current Weight

Drag the drop the Current Weight slider on the Body Weight chart to reflect the weight shown on the weight scale.


3. Set Your Fitness Goal

Drag the Goal Weight slider to the weight you want to reach and by the date you want to reach it.


4. Set Your Activity Level

Select the Activity Level you will maintain from the current date up to the goal date.


5. Check Your Daily Calories

After updating the parameters in previous steps, take note of what your calculated daily calories should be in order to reach your selected goal and update your daily meal plan to match the calories specified by BodyEngine.


6. Follow Your Fitness Plan

Refer to the Fitness Plan for a summary of the information and parameters updated in previous steps. From the Fitness Plan window, you will also be able to share your fitness goal with your Friends on your Facebook wall.


Setting Body Weight

Body Weight Chart

Use the Body Weight chart to set your current weight, goal weight, and goal date.

Figure 1: Body Weight chart

The Body Weight chart includes the following elements (Figure 1):

  • Weight and Time range axes
  • Weight sliders
  • Weight progress line
  • Body weight colored zones
  • Zoom controls

Chart Axis

The vertical axis on the left represents your body weight in pounds (lb). The weight range displayed on the chart starts from the underweight zone up to maximum weight of 400 lb.

The horizontal axis represents the time range starting from one or more months in the past to six or more months in the future.

The vertical axis on the right represents the Body Mass Index (BMI) divided into five levels: underweight, healthy, overweight, obese, morbidly obese.

Weight Sliders

On top of the chart you can see two sliders: the Current Weight slider and the Goal Weight slider.

Current Weight Slider

Drag and drop the Current Weight slider to set your current weight as of today by moving the slider up or down. The current weight slider is always fixed on today's date and is limited from your healthy BMI weight up to a maximum weight of 400 pounds. At this time, this is the only weight range supported by BodyEngine.

Goal Weight Slider

Drag and drop the Goal Weight slider to set your desired weight and the date by which you want to reach that weight. You can set the desired weight by moving the Goal Weight slider up or down, and your target date by moving the slider left or right. Notice that the slider's movement is bound within a weight and time zone (represented by dashed-lines) that is supported, safe, and feasible (see Goal Selection Zone for more information).

Weight Progress Line

The line between the sliders (your current and future fitness states) shows your projected weight from the current date to the goal date as you follow the fitness plan calculated by BodyEngine. You can click at any point on the progress line to see the intermediate state on that day.

For example, as shown in Figure 2, if you weigh 200 lb on August 21 and your goal is to weight 180 lb on November 1, by clicking on the progress line you can see that on September 11 you will be 193 lb if you follow the Fitness Plan calculated by BodyEngine.

Figure 2: Progress line with Current, Goal, and Intermediate fitness states

Weight Zones

The weight chart is made up of different color zones to help you see if your current and goal BMIs fall in the Underweight (yellow), Healthy (green), Overweight (yellow), Obese (light red) or Morbidly Obese (dark red) level. The actual BMI score for your Current and Goal weight is shown on the Fitness Plan page (see Following Fitness Plan).

For example, if your Current Weight slider falls in the upper yellow zone, according to the BMI scale you are currently Overweight. However, you can instruct BodyEngine to guide you towards a Healthy BMI level by moving the Goal Slider in the green zone.

Chart Zoom Controls

Click on the zoom-in [+] and zoom-out [-] buttons at the top right of the chart to increase or decrease the weight range displayed on the chart. Alternatively, you can also zoom in by clicking once on the chart and using the mouse wheel to zoom in or out.

Zoom in if you have difficulty with setting the weight sliders at an exact weight value or zoom out if you want to see where your weight falls into the color-coded BMI scale. As a convenience, you can also use the Optimal zoom button [] to adjust the zoom level to show both the current and goal weight at a zoom level that is convenient for positioning the sliders.

If you move the slider really close to either the top or bottom edge of the chart, the chart will zoom out automatically to keep the sliders within view.

Setting Fitness Goal

Goal Selection Zone

As you move the goal weight slider on the chart, you will notice that it is restricted within the dashed lines which surround the Goal Selection zone (Figure 1). The Goal Selection zone is limited to weight and date ranges that are supported, safe, and feasible. As you update your fitness parameters (e.g. current weight, activity level), the selection zone will expand and contract accordingly.


Figure 1: the Goal Selection zone within the dashed lines (marked with red arrows) limits the Goal Weight slider

Goal Weight Limits

Minimum Safe Goal
The minimum current weight supported by BodyEngine is the lowest weight that corresponds to your Healthy BMI level (see Weight Zones). You cannot set your goal weight in the Underweight BMI zone because being underweight is considered unsafe and could result in health issues.

Minimum Feasible Goal
The selection zone excludes weight goals which cannot be reached by the goal date.

For example, if you currently weigh 180 lb, you will not be able to set the Goal Weight slider to 160 lb two days from now because that goal is not feasible with a safe and realistic diet and activity level.

Maximum Supported Goal
Currently, BodyEngine can help you to only lose weight. Gaining weight is not supported at this time and because of this, the goal selection zone is limited to a maximum weight equal to the current weight.

For example, if you currently weigh 180 lb, you will not be able to set the Goal Weight to 201 lb because that would require you to gain 1 lb.

Current Weight Limits

Minimum Safe Weight
The minimum current weight supported by BodyEngine is the lowest weight that corresponds to your Healthy BMI level. This depends on your weight and height. Weights that fall in the Underweight BMI are not supported at this time for safety reasons.

Maximum Supported Weight
The maximum current weight supported by BodyEngine is 400 lb. Higher weights are not supported at this time for safety reasons.

Setting Activity Level

Activity Level

Your physical activity level is a very important factor for managing your weight. You should think of your Activity Level as a commitment and try to integrate it in your lifestyle.

BodyEngine provides four Activity Levels (Figure 1): Very Active, Active, Lightly Active, and Sedentary. They are color coded to indicate healthy levels (green), levels that can be improved (yellow), and unhealthy levels with potential health risks (red).

Click on the Activity Level to set the average physical activity which you will be maintaining between today and the goal date.

Figure 1: Activity Level panel

How to Estimate the Activity Level

Compare the activities which you perform as part of your daily routine to examples listed in Table 1 and select the corresponding Activity Level category.


Includes only minimum activity associated with typical independent day-to-day living.

Lightly Active

Includes activity equivalent to walking briskly (at 3-4 mph) about 1.5 to 3 miles per day, in addition to the light physical activity associated with typical independent living.


Includes activity equivalent to walking more than 3 miles per day at 3 to 4 miles per hour, in addition to the light physical activity associated with typical independent living.

Very Active

Includes athletic training for 2 or more hours a day in moderate to intense exercise.





Mild Walking (at 2 mph) for 1 hour or less.

Brisk Walking (at 4 mph) for 2 hours.

Power Walking (at 5 mph) for 1 hour and 15 minutes.

Power Walking (at 5 mph) for at least 2 hours.





Jogging (at 6 mph) for 30 min or less.

Jogging (at 6 mph) for 45 min.

Jogging (at 6 mph) for 1 hour.

Jogging (at 6 mph) for at least 1 hour and 40 minutes.





Moving loan for 1 hour or less.

Hiking without load for 1 hour.

Hiking with a load of about 10 pounds for 1 hour and 30 minutes.

Hiking with a load of about 10 pounds for at least 2 hours and 10 minutes.





No activities besides light tasks around household.

Swimming in a pool leisurely for 1 hour and 30 minutes.

Party dancing for 2 hours.

Intense aerobic exercise for at least 1 hour and 15 minutes.

Table 1: Activity Level categories, intensity and duration.

How Activity affects your Goal Weight and Daily Calories

It is important that you update the activity level in BodyEngine to reflect your lifestyle because it affects your goal state and your daily calories (Figure 2). Increase your activity level if you want to set a more aggressive goal and/or consume more calories. On the other hand, by decreasing your activity level you will limit the goal weight which you can reach and will lower your daily calories.

Figure 2: Effect of changing Activity Level. The Lightly Active level limits the goal weight to 153 lb and reduces the calories number by 10.

For Example: You initially set your goal weight to 140 lb by March 16 and commit to an Active lifestyle (Figure 2 left) by exercising three times a week. A few weeks later, you stop exercising and update your activity level to Lightly Active. Based on the new Activity Level, BodyEngine adjusts your goal weight and recalculates your daily calories accordingly:

  - Your initially set goal weight of 140 lb will change to 153 lb (see Setting Body Weight)

  - Your required daily calories will change from 2070 to 2060 (see Checking Calories)

NOTE: if you change your mind, you can select the Active level again and reset the goal weight to 140 lb.  

Checking Calories

Daily Calories

As you update your fitness parameters, BodyEngine shows the daily calories required to reach your goal weight (Figure 1). The calories number is also visualized as a plate of food showing your daily calories (partial orange circle) as a portion of the calories required to maintain your current weight (full orange circle).

Figure 1: Daily Calories Plate

Goal Calories

The goal calories number indicates the calories you should consume as your daily diet in order to reach your goal weight. The goal calories number changes automatically depending on your current weight, goal weight (see Setting Body Weight), and your activity level (see Setting Activity Level).

The number of calories recommended by BodyEngine are constant until you reach your goal weight. As such, once you start following your Fitness Plan, it is easy to remember the number of calories you need to consume and can easily adjust your diet accordingly. In order to reach your goal weight, you must complement your constant daily calories with your selected level of physical activity (see Setting Activity Level).

Daily Plate

The Daily Plate helps you visualize the difference between the calories required to maintain your current weight and the calories required to reach your goal weight. While losing weight, the Daily Plate will be only partially full, with the missing piece indicating the difference (daily deficit) between the goal calories and maintenance calories (Figure 1). While maintaining your current weight, the plate will be completely full.

The Daily Plate changes automatically as you update the goal weight and activity level. The lower your weight goal is, the lower the daily calories will be. The more active you are, the more calories you need to consume to support your physical activity.

Following Fitness Plan

Fitness Plan Window

The Fitness plan window presents an instructional detailed view of how to reach the goal weight selected on the Body Weight chart.

Figure 1: Fitness plan window

Fitness plan window displays the following data:

  • Current fitness state
  • Goal fitness state
  • Progress requirements
  • Progress statistics

Fitness States

The current fitness state on the left side represents your weight as of today, as well as your actual BMI score and the corresponding weight level (see Body Weight Zones).

The goal fitness state on the right side represents the goal weight which you have selected on the Body Weight chart, and the date when you will reach it.

Progress Requirements

In order to reach your goal, you must follow the dietary and activity requirements shown on your Fitness Plan for the duration shown. Ideally, you should commit to the same Activity Level and Daily Calories every day and integrate them into your lifestyle.  Since the number of calories that you need to consume is the same every day, you can prepare daily meal plans with a constant number of calories in advance and follow them day by day.

If counting calories is not convenient or possible for your lifestyle, you can try to estimate the calories you need to eat based on the ratio of your current diet (e.g. 75% = three quarters of the plate) or you can focus on cutting the number of calories shown for the Calories Deficit.

Progress Statistcs

In addition to the fitness requirements, the Fitness Plan also shows the number of days for which you will follow the plan, how much weight you are expected to lose between today and the goal date, and the projected average rate of weight loss per week.