1. Woodpecker is correct. Copyright protection of recipes tends to be weak because the idea of making, for example, green beans with almond chips is not protectable and because there are only so many ways to express a recipe for such dish. Copying ingredient-for-ingredient, amount-for-amount is forbidden. But in general copyright protection of recipes has inherent limits and is not strong.

The number of carbs is an empirical fact that derrives from the ingredients. I would think that the expression of those is in a limited number of ways and not enjoying strong protection.

Consult an attorney if you like, but I would not spend much time on it.

2. The bigger issue is your idea of opening a "different kind of low carb store." It will die. The gigantic food stores will make such store a subset of their own if you meat with success. Margins are thin in the retail business. I would encourage you to reconsider and not to live up to your name. The bottomline is that even the most devout low carbers do not really want to make a second stop in the grocery routine and your pricing will never give you the leverage to become the destination store for thousands of shoppers.