@Shiemiin Nah. The manga is completed and ended after its third volume, but we're currently missing the last two chapters if I'm not mistaken. No scanlation group is currently working on this manga (the last update was more than 10 months ago) so we'll just have to wait for now.
@sukaley Technically, assuming you know what you're doing with exercise and nutrition, losing fat without losing muscle at 15-25% body fat (going from normal to fit/ripped) takes a while even with a good high-protein diet. Losing fat without losing muscle at 40+% body fat (going from obese to chubby) can happen relatively fast.
Of course i wouldn't expect a teenage girl to have such knowledge. She's probably still stuck at the permacardio, zero strength training phase while eating a crash diet with 1000 calorie deficit and zero protein, lol.