Of course it is possible to Overeat Fat!! We don’t count calories but Calories Do Count. If you want to Lose Weight, you can’t drink loads of Butter and Coconut Oil in coffee. You keep carbs very low, under 20g, to force your body to use its own stored body fat. If you eat too much fat...it won't.

Don’t make these mistakes:
https://youtu.be/8mqHJh3xEWU


Ps: there are other health reasons that a high fat ketogenic diet works to control symptoms (epilepsy, dementia, etc) but you asked about weight loss.