Following all of your surgeon’s instructions is very important to get the best cosmetic results after a tummy tuck.
Don’t overthink things too much. As long as your weight was stable prior to surgery and you weren’t actively losing any weight, you should be in a good place in terms of nutrition during your recovery. I don’t typically assign a specific number as far as calories that my patients must consume after surgery. A better way of looking at your nutrition is to make sure you are eating 3 good meals a day that are full of good protein (chicken, lean meat), healthy fat (such as nuts like almonds), and some carbohydrates. Don’t be afraid to snack a few times each day. Colorful vegetables are good to make sure you get your vitamins and minerals, and it is OK to take a multivitamin. Good nutrition = good wound healing and better looking scars.
Don’t worry about the scale, your weight might fluctuate a bit in the months following your surgery. But I would be concerned if you were consistently LOSING weight after surgery, so it is perfectly fine to check your weight every week or two.