Junk Foods are basically foods that are low in nutrients such as vitamins, minerals & fibre and are high in saturated fats, added sugar and salt.

If you’re healthy then you can binge on junk food once in a way but not on regular basis . Eating junk food on regular basis can lead to a number of chronic diseases such as cardiovascular, type 2 diabetes, fatty -liver , and certain kinds of cancers. It can also lead to obesity, high blood sugar and high cholesterol.

Few of the junk foods are :

• soda
• chips
• candy
• cookies
• doughnuts
• cake
• pastries
• Fruit Drinks may provide vitamins & minerals but are high in sugar.
• Granola and health bars maybe free from high-fructose corn syrup and packed with whole-grains but these bars contain as much sugar as a candy if not more.

Similarly, manufacturers market gluten-free products — such as cookies, cake mix, and chips — as healthier options than their gluten-containing counterparts, even though both foods may have similar nutrition profiles.

Even naturally gluten-free products like certain juices, chocolate bars, and hot dogs are labeled as “gluten-free” to make them appear healthier.

Gluten is found primarily in wheat, rye, and barley, and only a small percentage of the world’s population must avoid gluten for medical reasons

Few of the info taken from :

https://www.healthline.com/nutrition/avoiding-junk-food#addiction