The new HSE clinical lead for obesity has said we spend too little on healthcare for the first three years of life.
"In healthcare we spend way too much on the last three months of life, and we spend too little on the first three years of life," Professor Donal O'Shea told RTÉ's Today with Sean O'Rourke.
Prof O'Shea, who said his long-standing passion was childhood obesity and prevention, gave his first interview on obesity in 1995 but since then population obesity at adult level has doubled while childhood obesity has trebled.
"If you were to tweak that [spending] a little bit, and give resources in the early years to prevention and education you would genuinely transform the future health of our country," he said.
He told Sean O'Rourke chronic diseases like obesity, cancer and depression can be mapped in relation to socioeconomic areas and people should not blame parents for childhood obesity.
"12% of our three-year-olds in socially deprived areas are obese, 4% of our three-year-olds in better off areas are obese. That's a massive disparity by the age of three," Prof O'Shea said.
"We know that obesity spreads through your environment. If a friend of yours becomes obese in the next five years, your risk of becoming obese increases by 70%," he added.
Describing himself as a "proud member" of Ireland's public health service, he acknowledged access to services and a lack of resources were still big problems.
"We simply can't afford optimum healthcare across the population. It would break the bank almost on a single disease if you were to do that. We have to decide how we use our resources.
"Previously we used to just throw money at a problem and you'd set up units without planning them. What has been made very clear to me is that there isn't spare money in the health service," he added.
Prof O'Shea also outlined elements of his pre-Budget submission including implementing an obesity action plan in hospital groups and community health organisations across the country.
"We need to put in place and build on the National Physical Activity Plan for Ireland - get people out, get people active, educate people around the healthy choice and start making that healthy choice easier," he said.
He added that while personal responsibility is a factor and prevention should be the focus, treatment is still needed.
"We have reached a point where we absolutely need to put in aggressive prevention and treatment strategies," he added.
He said obesity delivers all the chronic illnesses that cause cancer, dementia, and diabetes.
"If you could prevent those, some of those are 80% preventable, you would have people living longer and healthier," he said.
Prof. O'Shea said he has been asking for a tax on sugar, which is expected to be outlined by the Government in upcoming Budgets, for ten years.
"If you introduce a sugar tax you would educate people. It's a behaviour tax - a bit like the plastic bag tax. You would generate money. The Department of Finance say you can't put that money into obesity prevention but I would say that attitude has to change."