Rihanna "needs" to eat chocolate ice cream.

The 'S&M' hitmaker's personal trainer Ary Nunez refuses to deprive the star of her favourite "comfort food" when devising her eating plans and exercise regime, because she enjoys the calorific treat so much.

Ary said: "Chocolate ice cream is her comfort food. She says to me, 'I need my quota.' I believe deprivation leads to disaster, so I don't stop her - that'd be asking for trouble.

"Rihanna does not follow a diet although she tries to eat healthily on tour. She loves protein-rich foods, water, olives and fruit. She's in tune to how her body reacts to different foods."

The fitness expert also revealed Rihanna keeps in shape with martial arts training, including karate, tae kwon do and kung fu.

Art added to Grazia magazine: "She's very adventurous and confident, so we do a fusion of different martial arts together.

"Rihanna is smart about her body. We have fun working out together. She is all diva. She's all young spirit and a BFF type of girl."