Everyone's loose skin story is different. With very little doubt, if you are going to be losing more than 50-100 pounds or more, you will have some loose skin somewhere. I can certainly see where mine is developing. Genetics and age play a role in skin elasticity, so there are some people who have skin that bounce back fairly well, but there are plenty of people in their 20s with loads of loose skin, and people in their 50s who don't have that much.
There is also very little you can do about it. There are many people who have suggestions, but there isn't any real clinical evidence that anything works better than just letting your body do its thing and then deciding on whether or not you are okay with it, or not. Losing weight slowly seems to be the best way to allow skin to rebound somewhat, but it still depends on starting size, genetics and age somewhat.
The best thing I can recommend is to accept that it is most likely going to happen, and if you already know that it is something you'd want to get surgery for, then start saving money now in a special surgery savings account. You'll be losing weight for 12-24 months after surgery, and then most plastic surgeons will want you to maintain your weight for at least a year after that, so you probably have two to three+ years to save up enough money to put toward skin removal surgery.
Some insurance companies will pay for it if the loose skin are causing rash, sores, fungal issues and/or other issues that aren't treated effectively by other means. If it does seem to be causing skin or other issues (after you've established that you have loose skin) be sure to talk to your PCP about it, and make repeat visits to document the issues so it is easier to make the case for insurance.