the credit crunch is very complicated, but in simple terms, lenders have been hit by a large number of defaults on loans they have underwritten (EG US sub prime)and this has eaten into their liquidity reserves i.e cash reserves which they need to hold to stay in business. banks lend to each other on the wholesale money markets, and the rate for this(LIBOR) has increased due to the increased risk and therefore banks are unable to borrow money themselves in order to lend to customers at a cheaper rate. there's a lot more to it than that, but that is the basis of the credit crunch. oil and food prices are a seperate issue.

there are several possible reasons for food prices increasing:

1. In the past when we were as a country producing too much farmers were encouraged to diversify into biofuels, returning farmland to woodland, hedgerows etc, and many also went out of business.

2. Many poorer countries are enjoying rapid growth so food which was previously exported is now needed for their own population.

3. Poor weather globally has effected crop production.

4. Dealers are buying into commodities pushing up prices.

We can only hope things balance out over time as in the past.