It's like with what happened to her eyebrows, the same amount of hair was still there but because she was getting so fat, the skin inevitably stretches and spreads out the hair folicules. This leads to a 'baldening' if you will, but fucked up hormone levels and overall poor health from a shitty diet will not help that hair look any better no matter how tough her genes are. She's past her peak and the signs of decay are setting in already at only 30. It's all downhill from here, one mukbang at a time.More like she's getting so massive her head appears to shrink. And yes, she'll be bald by 40.