The 29-year-old singer is currently touring the UK with her Femme Fatale tour and is believed to have got herself hooked on the brown spread with toast, as well as on Mamite-flavoured crisps, Twilglets.
A source told The Sun, 'Britney got into the Marmite after one of her road crew told her she should give it a crack.
'When she was in Ireland she tried a traditional Irish meat stew and afterwards asked for some recipes.
'She's a very basic eater and will choose a pie and gravy over the fancy stuff.'