Undereating.

I keep reading things about how getting less than your daily amount of needed calories will stall weightloss but I'm not understanding it because you need a calorie deficit to lose weight? I started a diet and I'm just not as hungry because it's not fun to eat healthy so I'm likely getting under the amount of calories I need but I'm 30 lbs overweight so whatever. Has anyone lost weight cutting down calories less than you know you need? I'm not saying like an unhealthy amount but say 1000 calories or something? I'm not starving myself I've just lost my appetite a bit. Genuine question I know I'll probably get backlash but I'm just looking for advice I guess.