It's a colonizers food, but it is also survival food.
Imagine living your whole life by hunting and gathering. Imagine your traditional foods and medicines are violently taken from you, and all you are given for your survival is oil, flour and salt. Imagine how a diet of refined foods affects the people who are accustomed to eating wild foods.
The massacre of the buffalo was meant to be the death of us. Same with the ending of our fishing rights. The trail of tears was meant to be our end, but we are still here.