Suffering from stress fractures throughout her career the 29-year-old quit her vegetarian ways and started eating meat on the advice of her physiotherapist.
And, unhampered by injury throughout a season for the first time in five years, Campbell feels she is finally reaching her potential on the track over 1500m.
"I think the times I have run this year are more representative of my potential," said Campbell, who finished fifth in the 1500m at the Olympic trials.
"It has been really good for me because I have spent the last five years suffering with stress fractures and this year I finally feel fit.
"I was previously a vegetarian and I changed my diet which may have had an effect. I had a physio appointment and he said he saw a high prevalence of stress fractures among veggies so it was worth trying to eat meat.
"That, as well as more consistent training and more cross training where I spend less mileage on the road, I think has helped me make this season a success.
"Coming fifth at the trials was probably my season highlight. At the start of the season I was focusing on the long distance but I did my first 1500m and I felt I had more to give and I preferred it.
"My aim was to reach the final and I definitely exceeded my expectations."
Campbell, a Loughborough University PhD student, was particularly pleased to win the McCain Challenge Series as her winnings covered a well-deserved holiday.
And, having taken almost eight seconds off last season's 1500m personal best, Campbell plans to also impress during the winter cross country season ahead of next year's World Championships.
"It was a nice surprise that I was not expecting because a lot of girls have been running well this season but they had not run in as many races," she added.
"It means I can pay for my holiday with the prize money. This winter I am hoping to do well at the trials in order to get to the World Cross Country Championships next year.
"In terms of athletics hopefully I can finish higher in the UK Championships. And now I have had one and a half years injury free I will try to step up the training as I feel my body can handle it."
- stress fractures