how can I stay but still eat junk food?????

You can stay healthy by eating mostly healthy foods and much smaller amounts of junk food.

That depends upon how much junk fund you want to eat. In general, however, eating junk food and staying slim (I suppose that is the word omitted) is possible but not probable. I have a lot of personal experience at losing weight (my weight was like a yo yo for years) so I know how to lose it and how to gain it. Three main points to losing weight. I will list them is order of how important I think they are:
1. portion control. I think this is the MOST important. 1/2 cup of most vegetables (1 cup if raw) is a serving, 3-4 oz meat is a serving, and 1 cup cooked pasta is a serving. Salads are low calorie IF they are not drenched in a high calorie dressing.
2. Don't skip meals. Eat three meals a day.
3. Don't snack (or if you do, build that into your eating schedule and save a few calories here and there to make up for the snack calories).
4.(bonus) Read the labels. I watch the fat content. Those frozen dishes I can buy at the supermarket that are over 8 g fat content on the label are a no no for me.
Depending upon your frame and your height, calories are adjustable. For me, I try to stick to about 2000 calories a day. And it works. My weight is 150, I walk two miles a day (every day), my weight has been 150 +/- 2 lbs for the past four years. I am 5'9" and male.
I eat a hamburger once in a blue moon, I will have a pizza once or twice a year, and I go out to eat regularly. Most restuarants serve too much food so the first thing I do is separate the food into two halves. One half I eat there and the other half I ask for a take-home for my next meal. There are other tricks I have (such as giving myself a reward when I've been a good boy) but you don't want a book for an answer. I hope this is useful.

To stay healthy while still enjoying junk food, you can follow these steps:

1. Practice portion control: While it's okay to indulge in junk food occasionally, it's important to limit the portion size. Instead of eating a whole bag of chips, have a small handful as a snack.

2. Balance your meals: Make sure the majority of your meals consist of healthy, nutritious foods like fruits, vegetables, lean proteins, and whole grains. Include smaller portions of junk food as a treat, rather than making it a regular part of your diet.

3. Plan your indulgences: Instead of spontaneously reaching for junk food whenever you have a craving, plan specific times when you allow yourself to enjoy it. For example, designate a specific day of the week as your "cheat day" and enjoy your favorite junk foods guilt-free.

4. Substitute healthier options: Look for healthier alternatives to your favorite junk foods. For instance, swap fried potato chips for baked chips or air-popped popcorn. Choose dark chocolate with higher cocoa content instead of milk chocolate.

5. Mindful eating: Practice mindful eating by savoring each bite of junk food and being aware of how it makes you feel. Slow down while eating and pay attention to your body's hunger and fullness cues. This can help you enjoy your treats more and prevent overeating.

Remember, maintaining a balance between healthy eating and occasional indulgences is key. Keep in mind that moderation is key, and it's important to prioritize your overall health by focusing on a nutrient-rich diet.