Nutritionix Support Center

Q: How do we determine calories burned?

A: To determine how many calories are burned during an activity, we reference METs listed for each activity in the Compendium of Physical Activities. MET stands for metabolic equivalent, which is the ratio of the working metabolic rate to the resting metabolic rate. 1 MET is equal to 1 calorie per kg of body weight burned per hour. The higher the MET, the higher intensity the activity is. To determine calories burned, you simply multiply the MET of the activity by body weight (in kg) by duration (in hours).

While this provides a great estimation of calories burned, it does not take into account other factors such as age, gender, and height. We take those factors (along with weight) to determine an adjusted MET for each activity. This gives a more personally tailored estimate of calories burned.

Keep in mind that even with all of these factors accounted for, these are still just estimates. Here are some tips to make exercise tracking easier and more accurate:

· If logging an activity such as running, jogging, walking, or hiking, log the distance traveled instead of time spent. Our system uses an average speed for each of these activities, so if you move at a quicker or slower pace logging the time may result in an under or overestimation of calories burned.

· If you use an activity tracker or monitor that provides information on calories burned, you can log those calories directly into the app! Just type a phrase like “burned 500 calories running” and we will take care of the rest.