At least in America, food is basically free. If you are fine with eating the same food over and over again and have time to cook, you can eat for $10 per week in most places. Rent and higher education, on the other hand...

$10 per week? What food are you thinking of?

Beans and rice, bought dry in bulk. It won't be fun, but you'll live, for roughly $10 a week or even less.