Feelings and shit are scary. I mean okay, let's just slow down for a sec and think... What exactly would Amber fill the food void with? No really, think about it... Imagine her routine, from gasping awake in the morning (4pm) to bed time. All she knows is eat, go out to eat, get delivery, throw slop together and eat. The only time she bothers to converse with Becky or anyone else for that matter is when she's in the process of procuring or devouring food. It's a good distraction from actually having to converse or pay attention.
Just imagine sitting across a table with the half braindead sloth looking Becky with no plate of food in between you, just staring, and she starts talking.. and talking.. and she just won't stop about the nephews and... Goddamn. So you want to get away from that but if you're not going to eat then.. what do you do? Amber doesnt know what, and has no interests beyond food so.. guess it's back to bed then, good day. Yeah that's why she's terrified of real change, she's an empty husk and knows it, there's no meaning to life without her lord and savior Orange Chicken. Without the constant comfort food, and the crippling morbid obesity that excuses her from most of life's responsibilities she wouldnt know what to do with herself.