Conservatives leader Colin Craig says he has lost 30kg to prepare for election year by giving up cream buns and mince pies.
Mr Craig said that in June his weight had reached 105kg because of his fondness for "the bakery section".
"In the middle of last year I made a very serious determination that I was going to get into good physical condition. I knew I'd need to be in good shape this year."
Mr Craig cut all sugary foods from his diet and began walking and lifting weights before work.
He no longer drinks alcohol except at social events.
He walked on a treadmill for 45 minutes most mornings while watching documentaries and political debates from the US and the UK. The Conservatives leader said it was "easy" to lose the kilograms once he had weaned himself off sugar.
The aspiring politician and businessman now tipped the scales at a gaunt 75kg.
Asked whether he could get any thinner, he said: "My body has naturally levelled out.
"I'm the same weight that I was in my early 20s. I've pretty much got the same physique.
"That's the criteria for me. I'm in that sweet spot, at my perfect BMI. It sets me up for a good year."
Colin Craig's weight-loss programme
• No sugar
• 45-minute walk, 3 to 4 days a week.
• No alcohol except at social events.