Can I send calories by API to my Garmin personal account?

The Health API available to approved developpers can only read data from Garmin. You'd need the Health SDK for that purpose, and it is reserved to business partners of Garmin, and it is subject of license fees, so I guesss you do not have a big chance to get hold of it. You can try looking at MFP, whether your app could send the consumed Calories to Garmin through their API. You could perhaps (but only perhaps) import the Calories through the Import page (what could be automated in your app too), but I am not quite sure whether the supported FitBit file format allows sending of consumed Calories, and whether they are accepted by GC. You'd need to find out at FitBit, and test it.

You could also check out the Connect IQ API, but I doubt a bit it can be used for that purpose.

thanks for the clarification, Ill try to get access to MFP.
I sent a request to MFP developer portal and waiting for their response

Following. I would love to be able to import from loseit to Garmin.

ByondF1 said:

I would love to be able to import from loseit to Garmin.

If you want to develop the interface yourself, request the access to the Health SDK. Otherwise you'll need to ask Loseit to do it. Garmin offers a multitude of API's, but generally does not code any integration of 3rd parties - that needs to be done by the respective 3rd party. The problem is that many 3rd parties refuse doing it, because it costs money not only for the programmers, but in some cases also in license fees for the API access.