She'd attended the Liggins-led programme LENScience while she was at the Taonga Teen Parent Unit at Clendon's James Cook High School.
The programme shares the latest health science about obesity with secondary school pupils.
On the panel - to be chaired by Liggins co-founder Professor Sir Peter Gluckman - she'll speak about how evidence-based education could help young people in junkfood-filled environments like that of her old school in Clendon.
She recalled a host of low-price bakeries and takeaway bars selling deep-fried foods, a supermarket advertising two 1.5l bottles of Coke for $4, and a solitary fruit and vegetable store in the local shopping centre.
"Every Tuesday and Thursday the students are allowed to walk across and buy their lunch; can you guess what they come back with?" she said.
"How can young people make healthy food decisions when they're being suffocated by an excess of unhealthy options?"
But slashing exposure to fatty foods was just half the battle and she believed the fight against obesity first had to be waged through education, targeted at pupils from a young age.
"The community will simply head elsewhere for the food they're used to, food they've been raised around."
With a third of Kiwi children aged 2 to 14 now considered either obese or overweight, childhood obesity has become an increasingly urgent health issue in New Zealand.
But the LENScience programme, which promoted scientific and health literacy in general, was among projects making a measurable difference.
Ms Crosbie hoped its evidence-led approach would prove a valuable example at the conference.
Travelling with her to Switzerland will be her partner, police constable Joshua Parsons; their 3-year-old son Luka will stay home with her parents.
