
According to the ECB, Jaffa cakes are "eaten by sportsmen and women due to the high-energy credentials and the fact each cake has only 1g of fat." McVitie's Jaffa cakes are also a licensed FA product with England, meaning the cricket deal leaves me one option: I will now be eating quantities of Jaffa's due to advertising.
I haven't actually seen any cricketers or footballers eat the cakes yet, and this high-energy thing makes no sense to me as I usually eat them having kicked back on the sofa with a cup of tea.
Anyway, here's an authoritative reason why sports people eat them.