I'm a doctor, though I haven't had the ?good fortune to treat many bulemics. It's thankfully rarer here in India than in the West, even if I agree with Scott's theory that it's largely social contagion, it's only slowly taking root.
To put it as succinctly as possible, yes, though that's orthogonal to whether or not it's a good idea.
I can't see where the question even arises really, if you're eating a relatively normal amount of food yet vomiting it back up, you're clearly not getting most of the calories, especially since bulemics try and purge themselves as soon as they can instead of timing things.
Weight loss is obviously a sign of bulemia in clinical practise, most of them have a distorted self image/dysmorphia where despite being quite slim or even thin compared to their peers, they perceive themselves as overweight or at least desire further weight loss.
Regular self-induced vomiting has plenty of downsides, including the erosion of teeth enamel from repeated exposure to stomach acids, dyselectrolytemias from both loss of gastric fluids as well as an improper diet, and finally the cardiac strain from a grossly insufficient intake of calories.
If they're within a normal-ish weight range, we usually refer them for therapy or other psychiatric services, but if they drop down to a very low BMI they often need to be admitted for supervised care.
CICO (accounting for absorption) is trivially true, even if our biology makes adhering to it difficult, and I for one am very glad that Ozempic and other GLP-1 agonists are on the market for obesity, not that the typical bulemic should take them for the purposes of losing weight.
TLDR: Yes, and it works too well, hence the associated health risks.
In my experience the best way to sate hunger is to have multiple gallon jugs of water lying around and drinking too much water when you feel hungry. I know this is a little off topic, but it's likely a better solution than bulimia.
I have a family member who used to vomit daily. I never noticed any negative effects on him from it, apart from the rapid weight loss; which I guess is the point. I guess the general disgust other people felt around him when he went off to go throw up was a pretty negative effect. Also his weight loss looked unhealthy. He had twig arms, still had a lot of stomach fat, and was generally much more irritable than usual.