Carbs and Protein

Somebody told me that you need to watch how much protein that you take in because if you take in too much then your body will metabolize the protein instead of carbs and eventually get used to using protein instead of carbs. Is this true? This puts me in a tricky situation because I’m trying to loose body fat so I’m trying to limit my calories, but I don’t still take protein to supplement my muscles. Any help would be greatly appreciated.

Thanks,
Mike