title: Limiting returned wordpress fields from WP_Query or 'get' functions
body: <p>Looking to limit the returned fields of a WP Query to help with speeding up the response from the server and reducing the amount of data retrieved. For the query I'm using, it only needs up to 3 fields of data, the rest is brought in through ACF get_field_object in the loop. Other functions I'm using such as get_posts or get_terms have field options but are limited to a small number of things, such as 'slug' only or 'id => slug'. </p>
  
  <p>I'm used to developing in CakePHP, which has the option to specify each and every field to return, but the project calls for wordpress for other functionality and so I'm quite limited.</p>
  
  <p>TL;DR need to speed up getting posts from Wordpress</p>