Hi there, beef potpie would be contradicted for a fast indeed, a fast being the total abstension of food or a partial or modified fast that may include liquids such as water or juice of veggies and or fruit.
What you are describing does not seem to be a fast however but a change of diet for several weeks. A question here is what are you hoping to achieve here? are you looking for proof that a healthier diet is beneficial? are you feeling that a great leap can be made in several days to overcome the habits of many years?
What I would suggest is not so much a diet or a fast but a change of lifestyle where you incorporate a change in diet that agrees with what you already know. You already know that fruits and veggies and other fare is healthier than what you have been ingesting. I can tell this by your desire to test things out and change. Go for it. As the changes occur you may undertake different fasting regimens as you are ready. Do what you know is right don't go on a diet diets last some days weeks or maybe months but by definition are meant to fail because you expect to go off them at some point. If you are looking for a quick fix don't even try.....you must devote your self to a change that is permanent. Dive in so to speak. So no do not start your diet over....simply keep moving in the right direction.