I don't think anyone had my dear old Granny in mind when they came up with the grandma diet - unless gin and pate are counted as whole foods

They say that you can buy your basic food essentials just by walking around the outside of the supermarket (as in isle 1, along the back & then the last isle) - of course that doesn't include things like oats, flour etc.
That's pretty much true - it's designed so that you have to go through the aisles to get to all your staples and you enter through the fruit and veges to make you think it's fresh.