Meat pies that are made commercially are considered to be junk food because the manufacturers of the meat pies can make them unhealthy.
They may use a lot more salt which is not as healthy and use other artificial ingredients that are not healthy for you either.
However eating meat pies in moderation is okay and meat pies are healthier for you to eat than other Junk Foods such as chips, candy etc.
Meat pies that you make at home with your own ingredients and if you use more natural ingredients in your homemade meat pies would be much healthier for you than meat pies that you buy in stores.