The fish case-study is a good example of how cultural and religious beliefs play and important role in dictating decisions about dietary choices.  For much of the over-fishing that we see in the seas today had its origins with the introduction of Christian fasting traditions, bought in during the 10^th century, that required ecclesiastics and later the general population to avoid the consumption of animal flesh on days of fast (fish were not deemed to be meat and so could be consumed on fast days).

The idea of eating ‘fish on a Friday’ is a remnant of this medieval tradition and many, even non-practicing Christians, still follow this tradition.

This highlights the inter-linked nature of culture and diet but also how long-standing food practices can be continued as a statement of religious identity, even when they have lost their meaning.

It is now time to recognise, however, that some traditions need to change, and new food preferences need to be adopted.