In a blender or mixing bowl, combine the 2% milk, vanilla protein powder, sugar-free vanilla pudding mix, and salt. Mix until smooth and well combined.
Gently stir in 1 cup of diet or zero-sugar orange soda.
Pour the mixture into your Ninja Creami pint. Place it on a level surface in the freezer and freeze for at least 24 hours.
After 24 hours, remove the pint from the freezer. Run the sides and bottom of the container under hot water for 1–2 minutes to loosen the ice cream.
Spin the pint on Lite Ice Cream mode.
Respin 1–2 times until you achieve your desired consistency.
Enjoy!