Gunnell, who grew up on her parents' farm in Chigwell, has signed a two-year agreement with First Milk and will provide insights on the benefits of effective nutrition and protein within a sports arena as well as in the home, according to the firm.

She will also help to develop and promote new areas of focus for the company, which claims to be the  only major dairy company in Britain which is 100 per cent owned by British farmers.

First Milk owns dairy brand Lake District Dairy Co and sport nutrition supplements provider CNP.

"Sally brings with her a passion for healthy living, she's someone that has real-world knowledge of what it takes to be successful - both as a sportsperson and as a mother," said David Young, marketing director at First Milk.

"As such, she's a great asset to First Milk and I've every confidence that we'll continue to drive NPD (new product development) with her at our side."

Gunnell, 47, won Olympic gold at Barcelona 1992 and followed that up a year later with gold at the World Championships in Stuttgart, setting a then world record of 52.74sec.

Sally Gunnell powered her way to Olympic glory at Barcelona 1992 ©Getty Images