Sugars a hell of a drug. To the point where our brain has evolved to be hooked on sugar. Every organ in your body, from the liver, to the pancreas, to that little muscle near your balls that lets you sorta flex your groin has evolved to literally eat themselves before letting your brain lose it's access to glucose. But those processes take time to engage.It baffles me that she can't let go of carbs, it's like watching a heroin addict say "I am not doing heroin, I am being healthy " then proceed to do a line of coke.
When you're sexual escapades in the amazon lead to you starving in some back water tribal village, you might just confuse it with being hungry or tired. But that first week of the diet, the most important part, is where your body is making more glucose transporters to cope, and starting to process adipose to make it into sugar through gluconeogenesis, so it can ship it to the brain. In that week or two, your body will fucking crave sugar like it's no ones fucking business, because your brain literally feels like it's starving. you aren't of course. You're just being a little bitch, but the only time your brain isn't on glucose is when your basically kicking the bucket.
I know I've both under and over explained this, but your comparison to heroin is extremely fitting. 99% of this woman is literally dead weight, producing nothing while screaming for glucose. Her brain screams for glucose. Whatever is left of her muscles scream for glucose. She's over 500 pounds of sugar junkie, literally unable to escape from the sugar surrounding her.
It reminds me of when I started eating sugar again after around 3 months of hiking through Alaska. It started with a glass of lemonade, and 2 days later I was fucking gorging myself. I couldn't imagine being 550 pounds, with literally nothing to do but fucking eat.