Oso Polar

It is definitely possible. In 2017 I've started riding and in about 7 months lost about 75 pounds without much effort. But it is not about riding, it is all about eating. Riding will help you to maintain good physical shape, changing diet to something low carb + high fat and less calories will help with weight reduction. Apart from riding, go to gym as well. And do riding and gym not just once or twice a week, do it much more frequently (I usually ride or go to gym 5-7 days a week). You don't want to eat less and don't do any exercises - you will lose weight but you'll become weak, muscles will be the first to go but fat will stay.

BTW, I find it much easier to lose weight while riding longer distances at a slower rate than ride shorter distances but much faster. Basically, riding at lower speed doesn't really require any snacks for hours, it is very easy to eat pretty much normally. However, it is simply not possible to ride hard and not eat during the ride and/or get serious hunger afterwards, the end result being that your weight may actually go up as you may overcompensate by eating too much, it is not easy to find a balance (especially at first).

For me, the process basically went in two stages. As I wrote, during first 7 months I've lost about 75 pounds (went from ~240 lb to ~ 165 lb, I'm 5'11"), I became stronger, bought a new bike, joined a local bike club and started riding on group rides (which proved to be way more challenging than riding solo). Due to this for the next few months I actually didn't lost any more weight but I became MUCH thinner, especially around the waist (pants 36 -> 29) and needed to change all clothes. Became much stronger as well. I guess it was fat changing to muscles which resulted in size reduction but not weight reduction.