EER Formulae

[Gondwana]

With my apologies, John... 😉

I'm trying to use the EER formulae here (in a Wear OS app). I question the "1.0 x" multipliers on these grounds:

• Multiplying anything by 1.0 doesn't make any difference and implies that those factors are placeholders for the real value(s).
• The Fitbit app seems to be using factors of about 1.2 rather than 1.0 to estimate my EER.
• Following the link to here, a PA factor of 1.0 would imply that Fitbit assumes or encourages users to be sedentary. Fitbit probably doesn't/didn't intend that. A factor of 1.2 would be between "low active" and "active", which is a more plausible and desirable goal.

Would it be possible to clarify what PA multiplier is actually used? If it's not 1.0, the documentation should probably be corrected (although I suspect I'm the only one who's ever tried to use those equations).

Utmost thanks!

[JohnFitbit]

Hi @Gondwana,

I'm not quite familiar with this section of the documentation, but I'll ask around and see if I can clarify what PA is actually used, and if the documentation is accurate.

I'll let you know when I have an update!

[Gondwana]

Thanks John. I know it's an odd question.

[Gordon-C · Accepted solution]

Hi @Gondwana 

I'm going through some old support issues and came across your question which was unanswered.  I've been looking at the documentation and the information on the CDC.gov site (https://www.cdc.gov/pcd/issues/2006/oct/06_0034.htm).  The content in the Web API documentation that you referenced is a really old section and likely needs to be updated or clarified.  The information in our documentation matches the CDC formulas, except for the "1.0" value that you're asking about.   From what I can tell, the person who wrote the content didn't post the formula.  Instead, they posted an example for when the user is sedentary.

According to the formula on the CDC site, EER is calculated as 

For men:

TEE = 864 − 9.72 × age (years) + PA × [(14.2 x weight (kg) + 503 × height (meters)]

For women:

TEE = 387 − 7.31 × age (years) + PA × [(10.9 x weight (kg) + 660.7 × height (meters)]

where PA is

For men:

Sedentary: PA = 1.0, when 1.0 ≤ PAL <1.4
Low active: PA = 1.12, when 1.4 ≤ PAL <1.6
Active: PA = 1.27, when 1.6 ≤ PAL <1.9
Very active: PA = 1.54, when 1.9 ≤ PAL <2.5

For women:

Sedentary: PA = 1.0, when 1.0 ≤ PAL <1.4
Low active: PA = 1.14, when 1.4 ≤ PAL <1.6
Active: PA = 1.27, when 1.6 ≤ PAL <1.9
Very active: PA = 1.45, when 1.9 ≤ PAL <2.5

I hope this information helps.

[Gondwana]

Thanks Gordon! Your support is amazing.

You confirmed my suspicion about the 1.0. Based on reverse-engineering of the maths for my own case, it seems that Fitbit/Google is using PA of about 1.2. It would have been nice to get confirmation of this, but such things are probably proprietary. I need to do this calculation in a Wear OS app because Wear OS doesn't make it easy to access Fitbit data.