The Metadata API has never really been the most optimal API for an IDE, hence Salesforce are now working on the Tooling API (currently in Pilot). So I would not be surprised to see it use more than one, but 24 API requests does seem quite excessive. I have just done a Save and consumed 3 API requests. There is a report you can run to get a little more information. 

Click on Reports, and under the Administrative Reports folder you'll find this...

![enter image description here][1]

[Force.com API Usage Limits](https://na11.salesforce.com/help/doc/en/integrate_api_rate_limiting.htm#rate_limits_title)


  [1]: https://i.sstatic.net/QVYFt.png