Junk food doesn't necessarily lack in terms of satiation, depending on what you mean by junk food. A big ass grease burger is certainly going to fill you up and might keep you full for quite a while, while a candy bar will not. Certain fats and sugar could both be looked at as junk food, but fat works pretty well for satiation and sugar does not. The problem is, fat has over twice as many calories per gram as protein/carbohydrates, so you will eat up your calorie limit far quicker if you turn to fat for satiation rather than protein or fiber.
The term "empty" calories in regards to junk food generally doesn't refer to satiation, it is more about their lack of nutritional density.. If I eat 100 calories of vegetables I am filling my body with vitamins and minerals and fiber and revving up my metabolism as my body digests the food. If I eat 100 calories of Skittles, I am adding nothing to my body but a quickly digesting source of energy (sugar), and when my body has no more use for that energy it is stored as fat. If you are on a calorie deficit that won't matter, because your body will just use that sugar for energy and then whatever energy it still needs will be burned mostly from your body's fat stores--so you will still burn fat, you just won't get the other nutritional benefits, thus "empty" calories.
The higher your maintenance calorie level, the greater the chance you will have to get a full days worth of nutrition while still being able to eat these empty calories and remain a fat burning machine. With my gender, height, weight, age, and activity level, my maintenance calorie level is about 2,650. I find it very easy to get a ton of protein, fiber, healthy fats, and slow digesting carbohydrates and still end my day with 400-500 calories to spare. I do whatever I want with those remaining calories and I am very lean, and even back while I was on my year long weight loss journey and wasn't already lean I was still doing whatever I wanted with those spare calories and I continued to drop fat. However, as a non active female, the OP probably has a maintenance level more around 1,800 so it will be hard to get muscle building, metabolism booting nutrition while still eating crap foods.