I&#x27;d say the calorie is fine (other than being obsolete, you should use Joule. 1c = 4.2j). It may not be easy to measure with high accuracy. That&#x27;s not going to change with a new system.
Also, just because the body sometimes can&#x27;t use parts of the calories you feed it, doesn&#x27;t mean it&#x27;s broken.