I briefly looked into how you make a food safe painted plate at home and the answer seems to be "easy if you have a kiln".
You might be able to find a paint your own pottery store near you. I went to one with some friends and it was a lot of fun and I got a colorful owl coin bank for like, $10 or something. Just have to make sure it's food safe, but they usually coat everything in a glass food safe glaze so it should be.
Unrelated, weed is legal where I live, so when I checked the website for the place I went, it had big banners for "summer kids clay classes!" And "pot-tery for adults!" right next to each other.
It totally makes sense but part of me is still startled by tangential consequences of legalization.
"Food Coma / Foodie" are in the image, and that's pretty solid. Maybe "3-Star / 5-Star / Greasy Spoon"? I like the one that you came up with that ends with "thanks Grandma."
I get your point, just know that there is other more purpose designed plates which can help people get an idea of the right portion sizes. The picture here has it photoshopped on but I've seen plates with this printed on and it seemed helpful
These plates are a passive, very visual reminder. A tracker app requires you actively use the app, and not consciously/subconsciously underestimate portions.
Neither is a holistic solution, both require buy-in, each is going to have different effectiveness for different people.
I feel like there's a toxic body image/patriarchal component to only eating the large portion once you are a mother/soon to be a mother. Something about "letting yourself go" or something terrible like that