ORPHANED animals are set to benefit from a group of Bundaberg women who shed more than 60kg and donated the amount of their weight lost in pet food for the RSPCA.

The women have all embarked on their weight-loss journey through the Michelle Bridges 12-Week Body Transformation and, as part of an eight-week mini milestone celebration, they decided to carry the pet food the 20km return trip from Lake Ellen to the RSPCA shelter.

Organiser Kylie Lassig, who has lost 20kg in three rounds of the program, said the group wanted to help out a charity while celebrating their own personal weight loss achievements.

"We wanted to do something that was big and that was going to be a big calorie burn," she said.

Six of the women donated a total of 64kg of food, although only four of them did the challenging walk - with some carrying 20kg alone all the way to the animal shelter in Bundaberg West.

"We were all hurting by then," Mrs Lassig said.

"I had two bags - a backpack on the back and front."

Mrs Lassig said during the walk on July 28, reality set in that she had once been carrying that weight every day.

"The best part was when I took it off and went, 'wow' - I'm never going to let that weight get back on," she said.

Donna Habermann also carted 20kg of dried food despite trying to overcome tennis elbow.

"I had a trolley bag but I lost a tyre so I had to carry the rest," she said with a laugh.

Mrs Habermann said it was hard to imagine she had been carrying the extra weight and just how heavy 20kg actually was.

"My knees started to ache - all those pains you'd get before," she said.

"You never want to put that weight back on."

RSPCA shelter manager Vicki Beer said the donation was most welcomed.

"We need all the donations we can get," she said.

"It was great."