1200 calories a day usually gets treated as the go-to "diet" number, but it's worth saying the obvious thing plans rarely admit: it's low. Dietary guidance generally treats it as close to the floor for a smaller, fairly sedentary adult woman — for most men, active people, or anyone with a bigger frame, it's not a sensible everyday target at all (it's closer to what used to be prescribed briefly under medical supervision, not a number to freestyle into for months). If you've landed on 1200 without a doctor or dietitian involved, and for reasons that aren't medical, it's worth double-checking that it's actually the right number for you before building a whole week around it.
If 1200 really is your number, the trick isn't willpower, it's food choice: protein and high-volume, high-fibre food (think vegetables, legumes, lean protein) fill you up for far fewer calories than the alternative, so the day feels survivable rather than punishing. This planner builds a 1200-calorie plan around your protein target and diet rather than just hitting the number any old way, then generates the shopping list to match. Set your calories and diet above and just try it — and if a low target is for a medical reason, that's a conversation for a doctor or dietitian, not something a planner can decide for you.