"I want to raise awareness and get the word out about how amazing the Cancer Society and Ozanam House Trust in Palmerston North is."
The Trust is an organisation that provides accommodation for people during their cancer treatment at Palmerston North Hospital.
The trust has enabled Miss Campbell to go down and stay with her Nan in her own house.
"It is amazing down there, they look after her so well and she has her own house just down the road from the hospital so she doesn't have to stay in the hospital the whole time."
The 17-year-old said her Nan was more like her best friend, who she borrows clothes from, chats for hours with and just has a lot of fun with.
While visiting her Nan, Miss Campbell was blown away by the care she was receiving.
She said the Cancer Society does amazing things, which she had now seen first-hand.
She said they offered makeover programme 'Look Good to Feel Good', which taught patients how to do their wigs and other beauty ideas.
"They also helped Nan buy her first wig and she looks amazing."
Junk Free June was going to be tough for Miss Campbell, as to her it was about cutting out the sugar and unnecessary food or sauces in everyday meals.
She said she would be okay with giving up chocolate and lollies but would find cutting out bread, mayonnaise and other sauces that you don't think twice about, the hardest.
"My friends are sweet tooths too so I will have to be strong and not get tempted by them when they're eating sweet food.
"I just hope that what I am doing will raise awareness to others about what these amazing charities do for people."
Miss Campbell said giving up junk food for a month was nothing in comparison to what cancer patients have to go through daily.
She has a target of $500 to raise for the Cancer Society and as of last night she was already halfway.
To donate visit: nz.junkfreejune.org/participants-and-groups/olivia-campbell-1 and to donate towards the Ozanam Trust visit: www.ozanamhouse.org.nz/Donate.