my boyfriend does this , he was raised in a family where they got what they got and they couldn’t complain , so it’s trauma from his childhood but the best way to do fix this is to try and savor the bites and figure out what you can taste. my boyfriend says this helps

Eating slowly is better for your metabolism than eating fast. Don't let anyone pressure you into eating faster than you're comfortable with. I used to eat fast and a lot because I was a defensive eater and also struggled with binge eating. My dad would threaten to eat or throw away my food if I didn't eat all of it or if I didn't eat it fast enough so I'd eat all my food really fast, even if it made me painfully full or I didn't actually want to eat it. I have some really good people in my support system that have been slowly helping me accept that it's okay to not finish food and it's okay to not force yourself to eat if you don't want to. You can always save it for later if you know you'll want to finish it, and there's no shame in throwing out food if you genuinely don't want it and don't have any one else that'll finish it for you. I used to hoard and hide food as part of my defensive eating habits. I'd end up never being in the mood to eat it (or I'd convince myself I didn't deserve to eat it) and it would go bad eventually and I'd have to toss it anyway. Mindful eating has helped me tremendously on learning portion control. Eat slowly, and as you do be conscious of how each new bite effects how you feel. Notice when you start to feel full and how much food it took to get you there. You can use that as a guide to know how much food you actually need for each meal and plan accordingly when you buy food in the future. It's an uncomfortable process but it really does help in the long run. Only buy food if you know 100% sure that you want to eat it. No impulse buying because you think you'll want it later. Keep ingredients stocked for safe foods that you can fall back on if you have nothing else you want to eat at the moment. It's totally okay to have the same thing over and over just because you know you'll eat it every time. What matters most is that you're eating enough to stay alive, you can worry more about what you eat as you start to learn healthier habits.