The full-figured fitness instructor
16 August 2013 Last updated at 02:15 BST
Fitness instructor Lauretta Johnnie runs classes for people with fuller figures who want to lose weight.
But unusually for people in her profession, she herself is plus-sized.
As well as benefiting those taking part, her Full Figured Fitness 'Booty Camp' classes around London have also helped her personally to get on the right track towards a healthier lifestyle.
Before she became an instructor Lauretta weighed almost 27 stone (171kg) - but since then she has come down closer to 21 stone (133kg).
She hopes that her classes will inspire overweight people who are nervous about taking part in regular classes, or who have faced discrimination.
"It's as if you become less human if you're big," she told BBC News.
Video journalist: Suraj Patel
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