No - they work on people with a "lil bit of Chub" they are currently getting sold online as the "forgotten secret" they are sold mostly to Ham-beasts who want to be better but not apply Will to Effort, and they only work for a bit you can out eat them or lose weight but it doesn't work for long it always had reprocutions that backfire.
I asked my better 3/4's and she says she see's this shit shilled all the time and it's always marketed as quick and natural and forgets to mention the other priblems that come along with it, She's a Veterinarian and if these things work at all even for a while are little more than a infection risk at best or a sham that hurts you at worst.
No, tapeworms leech the nutrients from you, not your fat. I mean, sure, when it kills you from malnutrition even though you eat 4000 calories a day and are still fat, after you start decomposing you will lose weight at a record speed but I don't think that's what you mean.
There's always the risk of eating too much and thus facilitating the growth of the tapeworm. And the thing about such worms is that they'll continue to grow so long as they have an ample supply of food; meaning that they can potentially fill your intestines to the point that you can't adequately absorb nutrients from the food you consume. They can also pass beyond your intestinal wall and grow even longer, but such is a rather rare occurrence.
My advice is to simply cut the amount of calories you consume on a daily basis, while also incorporating exercise into your daily routine. The results won't be immediate, but you'll be much better off than if you had a parasite impacting your colon.
They do consume some calories, but mostly just steal your nutrients. Don't do it, besides being disgusting, you also might spread microscopic eggs and infect others.