In article ], ] says...
In article , JamesB writes
Chris wrote:
What area of land is needed to feed a typical family?

10 poles.
*chuckle*
Standard allotments are 10 poles, or about 250 square metres. This
standard size was calculated as the right size to feed two adults and
two children.

Thanks for that.
Someone told me that the RHS had managed to do it using a three metre
square of land i.e. nine square metres.

They didn't grow food for a typical family, they wanted to show that you
can grow a variety of veg in a small space:

http://www.rhs.org.uk/vegetables/advice/veg3x3.asp

I have three 1mx3m beds - I've got garlic, shallots, onions, pak choi,
peas, mangetout, broad beans, carrots, rocket, lettuce, spinach, chard,
beetroot, swedes and parsnips coming through or near to harvest, plus a
variety of tubs with potatoes, French beans, tomatoes. I have about 14
'square foot' plots from 81 empty for June planting plus some tubs for
courgettes and squashes; by late June/July the alliums and potatoes
should be ready for harvest and I'll be able to plant more in the
vacated plots. I may not be able to feed the family for long (especially
when the slugs are active) but we'll get a few meals!