If you’re willing to do a diet that’s mostly grains and vegatables with limited protein and those grains are self cooked (i.e. steamed rice instead of store bought bread) a dollar per meal is doable. The problem is if you’re used to a western diet of meat and potatoes you’ll never stick to that diet.
Asians eat that way because they grew up that way and the vast majority of people in those countries can’t afford to eat differently. They eat rice noodles and vegatables with little bits of protein because protein is expensive there. In most 3rd world countries food is a much larger part of the budget compared to here where shelter is a huge part of the budget.
While it’s theoretically doable to come up with a budget that lives on 60k per year with kids and can save for a condo in San Diego. The reality is the people buying those condos aren’t a family of 4 making 60k year. Most people older than 40 to 50 can’t afford to buy a place where they currently live and their kids can’t buy that property either. Consider what that means for your estate.