This is Kate and Pippa’s secret to staying fit, claims their uncle

Turns out a bit of maternal nagging mightn't be any harm.

Kate Middleton and her sister Pippa are both famously svelte and it's no secret that they're big into fitness. Pippa reportedly took part in a hardcore three-month bridal bootcamp in the run-up to her wedding this summer, during which she ditched alcohol and met up with her personal trainer five times a week. Now, the sisters' uncle has revealed that their mum is the reason they're always in shape. Gary Goldsmith credits his sister Carole for instilling her love of fitness in the girls. "Carole has always looked after herself and eaten healthily and she has a stunning figure and that mentality of considering your diet and exercise is evident in the girls also," he said, according to The Daily Mail. "They eat healthily, they play sports, they keep themselves incredibly active." So there you go - your mum's nagging to get off the couch and ditch the takeaways could actually come to some good if you listen to her. Gary also admitted that their dedication to fitness has lead to some comparisons between him and the Middleton women. [caption id="attachment_364688" align="alignnone" width="594"] Gary and his daughter attend Pippa's wedding.[/caption]   He's even embarked on a fitness challenge recently to try to slim down. "A few years back someone asked me why I was super-sized when my family are so slim? Charming I thought, but it did strike a chord. "The family they were referring to was obviously my sister Carole Middleton and my nieces Kate and Pippa. "Part of this is to not let the side down and to raise my bar and to basically stop my daughter giving me grief about it, because in all the pictures, I'm the fat lad in the corner." We hear you Gary, nothing worse than a sibling showing you up!