If you've been paying attention to the stuff I've been writing you'd know that I've been encouraging people to eat healthy but most of us have an obstacle to overcome when tying to do so and that obstacle is the fact that junk food tastes good. It's a bit hard to criticize someone for eating things that taste good but we all have to cope with the fact that a lot of these things are poisoning us, so we have to reduce if not eliminate these things from our lives.
Despite what you may be led to believe the realistic process of eliminating these things is a gradual one but it is easier to start than one might think. The first step is proper education on the topic, if you can't explain why exactly something is bad for you you'll be less likely to avoid it, if a child doesn't know that touching a hot stove will hurt them they'll probably end up doing it at some point but if they know that it will burn they won't touch it. Seek out information from trustworthy sources and educate yourself on what you put in your body.
The next step is to convince yourself that the stuff you learn is actually true and important. There will be times where knowledge about a particular food is enough to get you to stop eating it (soda doesn't taste the same to me now that I know they are designed to make us thirsty) but this probably won't happen for everything and certainly not for everybody. The best way I know to convince yourself of something is through the words you use, if you say something enough times it will eventually become true in your mind. For months now whenever I'd come home from the store after having bought junk food I'd half-jokingly tell my roommates that I'd committed sin by buying a box of oreos or something, after doing this for long enough I rarely get the urge to buy that sort of stuff anymore.
But of course we will still end up buying these things from time to time, a few weeks ago I caved and bought one of those chocolate pies with an oreo crust covered in caramel. When I bought it I was intending to only eat one piece a day so that it would last a while. When I got home I ate a piece and it tasted alright but I felt awful soon afterwards. I correctly recognized that the pie was the problem and thought to myself, "If I eat a piece of this pie every day for a week I'll feel like crap for a week, but if I eat this whole pie in one day I'll only feel like crap for one day." Now I'm not sure if its necessarily the best idea for anyone to eat that much pie in one day but I did it and I was glad that I wouldn't have to go through the pain of digesting that for a week but only for a day.
The best way to avoid buying junk food is to learn to cook good real food made out of real ingredients. The fact that all the restaurants got shut down last year forced people back into their kitchens and many people started to learn to cook more things. Unfortunately it is uncommon to see people cook with real food, there's one soyboy I occasionally watch on YouTube will often use MSG when he does he'll sing out the letters MSG in a happy praiseful voice. Now I'm no violent opponent of MSG, but I do believe that if you have to add mysterious white powder to your food in order to make it taste good then you aren't all that great of a cook. The same goes for frosting, there are of course some cases where frosting is acceptable, but if you have to put frosting all over a cookie or a cake then you simply have a bad cookie or cake, good baked goods should be able to stand strong on their own.
Now will you die from eating a desert? You won't if you only eat them occasionally and in moderation and be sure to only treat yourself to the best. Ice cream is acceptable to buy from a store but any other type of desert you should make yourself from scratch. Why would you want to eat something out of some box that has a half dozen ingredients that you can't pronounce when you could enjoy the satisfaction of making something yourself with simple everyday foods.
Anyways, educate yourself about what food is good and bad for you, convince yourself that what you learned is true, then seek to live according to your newfound wisdom.