I just read the list and I can say from personal experience, I'd starve to death if that's all I planted during the year. For example - beets. In my family one person eats 3 beets a week. Times that by 52 weeks and you get 156 beet plants. That's not the 10-20 plants she lists. Broccoli - a person here eats 1/2+ broccoli head a week, times 52 gives you 26 broccoli plants. Not the 5-10 on the list. Carrots- the list allows for less than one carrot per week, but we routinely eat one whole large carrot per person a week. That equates to 52 carrots per person assuming the carrot is large. Not the 40 max on the list, and with homegrown carrots, they usually aren't big ones either. The same logic applies to the rest of the list.
In my situation, her list doesn't fit our lifestyle. We eat a lot more veggies.
Growing your own food isn't all that clean cut and simple. Just because you plant 30 beet seedlings doesn't mean that you'll get 30 nice sized edible beets. Not every plant is successful. Some seedlings simply don't form a beet, some may die, some may be deformed. Then there are the bugs and diseases that can ruin some of the plants. Add to that some bad weather and your useable crop goes down further.
200 square foot per person a year is impossible on my homestead. I don't know exactly how much square footage would be needed per person because my garden also produces livestock feed and surplus for trading & selling, but it surely is way more than 200. And when you start thinking about producing all or most of your own food, then the square footage of
land use goes up even more. Grains take a lot of square footage. Add
chickens,
rabbits, sheep, goats and even more land is needed......unless of
course you're buying all their feed which is kind of cheating in my book if you're claiming your growing all your own food.
On my homestead we produce 90% of our own food. I buy very, very little commercial feed......basically just what is needed for days when I'm away from the farm or sick. We eat out 3 meals a week, plus buy assorted spices, seasonings, grapes, apples, cherries, some cheeses, peanuts, cashews, some
milk, and a few incidentals..... thus the reason I can only claim 90%. We grow, forage, hunt, or trade for everything else. Thus I'm pretty certain that a 200 square foot garden isn't going to cut the mustard.