I do notice a HUGE difference when I do the grocery shopping (using lists, coupons, menus, a plan) and when my wife does it (when she’s flying by the seat of her pants, tired, stressed, PMS-ing, hungry, etc.) A huge difference.
Don’t ever walk into a supermarket if you’re hungry.
If there were ever an "11th Commandment", that would be it. I'll need to be extra careful tonight, when I do a bit of grocery shopping on my way home...after working out. lol