Also, does he brush his teeth? Or buy anything? There's a lot of trash that isn't food packaging.
How many tubes of toothpaste do you use per year? Sounds like you're using far, far more than necessary.
Though you can also just brush your teeth with baking soda and go tubeless if you wanted to.
Thinking back over the last week, I've bought grass seed, a dehumidifier, paper, toiletries, and some toys for my kids. All of those are easily overlooked but add up to me not being able to go a year without emptying my trash, even if all my food waste and packaging were removed.