Also, the GP doesn't read to me the way you're interpreting it. To me the GP has grown produce and purchased produce this year. The purchase hit him while the grown at home did not.
> If you're growing food to sustain yourself for a whole year, I'm assuming you're willing to sacrifice some indoor space to accommodate.
It would be unheard of for it to contain enough space to produce the family's annual supply of food. And pointless. If you're growing that much food, there's no reason to build walls around it.
I grow leafy greens in containers, and while not totally self sufficient, it provides a decent amount. I have multiple pots that I rotate through offsetting planting so new seedlings are going in as older plants are harvesting. If you're wanting head lettuce types then it's different, but if you just want leafy greens, you can totally do more than I think you're thinking you can.
1) you're taking my comment too seriously.
2) assuming I had enough space to subsistence farm for my household (I don't), I wouldn't try growing lettuce year-round. Lettuce in the cooler months, peppers and tomatoes in the warmer months.
3) the majority of the lettuce I've prepared in my home this year did come from my patio