Skip to main content

Does MacroFactor use energy expenditure data from my wearable activity tracker?

In short, no.

The MacroFactor team is open to incorporating this data into our algorithms in the future. In fact, it would be quite easy to do, because we already have the integrations necessary to sync with relevant devices and applications.

However, the decision to incorporate energy expenditure (EE) data from wearable technologies presents an interesting dilemma – if we include EE data from wearables, we incorporate their estimation error into MacroFactor adjustments. Depending on the wearable device and context of activity, this error can be substantial, nonrandom, and hard to predict.

Conversely, if we exclude EE data from wearables, MacroFactor’s algorithms will figure out a user’s total daily energy expenditure (TDEE). We are dedicated to transparency, and this article fully explains how MacroFactor uses a continuous, running assessment of energy intake and changes in total body energy to maintain an up-to-date estimate of your TDEE. The major advantage of this approach is that we know our current method of estimating energy expenditure works. If it didn't, that would imply that everything we know about human metabolism is wrong. The only downside to this approach is there's a small time lag; if activity levels decrease a lot, your TDEE estimate won't drop immediately to the full extent that activity levels decreased, and if they increase a lot, your TDEE estimate won't increase immediately to the full extent that activity levels increased. Incorporating activity data from wearables could potentially help us make appropriate adjustments a little sooner, but we'd need to have unwavering confidence that the data coming from the wearable technology is valid and reliable.

Dealing With Day-To-Day Changes in Energy Expenditure

Users often ask what types of adjustments should be made when energy expenditure is going to be atypically higher or lower than normal for a particular day. If your main focus is on long-term changes in body composition, no action is needed. Long-term body composition changes are dictated by the cumulative state of energy balance (deficit, balance, or surplus) over long stretches of time, so a single day of “mismatched” energy intake and energy expenditure, whether it results in an unusually large deficit or unusually large surplus, won’t have a meaningful impact in the long run.

If your main focus is on adequately fueling your body for a particular bout of physical activity, modifications might be warranted. For example, you might be gearing up for a long hike or a recreational race, and you might be interested in increasing your energy intake to facilitate that activity. In this case, one option is to make an educated guess regarding your anticipated increase in TDEE, and simply increase your energy intake on that day without changing any app settings. MacroFactor is adherence-neutral, so eating well beyond your calorie target will not unfavorably impact the app’s function in any way. MacroFactor’s algorithms will have no issue understanding, based on your patterns in energy intake and body weight, that the increase in energy intake was accompanied by an increase in energy expenditure.

Understandably, some users will be bothered by the idea of going over their listed calorie target. For this scenario, there is another (slightly more tedious) option. You could go to settings, and navigate to the “expenditure” section. In this section, you could go into the "dynamic/static" setting, toggle to use static expenditure, enter a suitable TDEE value based on your anticipated increase in energy expenditure, and tap the check mark in the top right to save. Then when your transient, short-term increase in energy expenditure is over, you would reverse the process. Navigate to the setting, switch back to dynamic mode, and tap the check mark in the top right to save.

Dealing With More Sustained Changes in Energy Expenditure

Sometimes, our increase in energy expenditure is not a fluke or a one-off event, but a change that will be sustained for more than a day or two. If the change in energy expenditure is going to persist for the foreseeable future, the same two options are available. If you simply leave your settings as they are, the app will recognize your change in energy expenditure fairly promptly, and adjust your TDEE estimate and calorie target accordingly. If you were concerned about the possibility of overeating or undereating during this transition process, you could also choose to eat above or below your calorie target based on an educated guess of your anticipated TDEE in response to your change in activity level.

Alternatively, you could expedite the adjustment process while adhering to the calorie target presented within the app by changing a few settings. To accomplish this, go to settings and navigate to the “expenditure” section. Change the “expenditure start date” to the most recent date available, then tap on “initial expenditure.” Tap “manual,” enter an educated guess of your anticipated TDEE value, and tap the check mark in the top right to save.

In some cases, changes in activity levels (and subsequent changes in TDEE) will persist for several days or weeks, but are temporary in nature. For example, you might have a 1-2 week event that dramatically increases your TDEE, and this event could occur multiple times throughout the year. If you are concerned about expediting these transition phases as promptly as possible, similar methods apply. You could eat above or below your calorie target based on an educated guess, without adjusting any settings.

Alternatively, you could change some settings to give the algorithm a head start on the adjustment process. To accomplish this, begin by making a note of your current TDEE estimate. Then go to settings, and navigate to the “expenditure” section. Change the “expenditure start date” to the most recent date available, then tap on “initial expenditure.” Tap “manual,” enter an educated guess of your anticipated TDEE value, and tap the check mark in the top right to save. When the event is over and you return to your typical physical activity levels, you would reverse this process. You would follow the same exact steps, but instead of manually entering an educated guess for your TDEE value, you would manually enter the TDEE value that MacroFactor was presenting before you initially changed it.

Summary

Based on current evidence regarding the validity and reliability of common wearable activity trackers, we have more confidence in the function of our algorithm than the measurement error of common wearable devices. Nonetheless, we plan to do extensive data analysis in the future to determine if we can leverage wearable technologies to refine the performance of our algorithms. If the data indicate that incorporating energy expenditure estimates from wearable technologies can meaningfully and robustly improve our algorithms without error, we will follow the data and update accordingly.