A firebrand Coalition MP has urged younger Australians to address the causes of their obesity as early as possible, after revealing he had 85 per cent of his stomach removed after his own weight reached the "point of no return".

Writing on his Facebook page, Liberal National MP for the Queensland seat of Dawson, George Christensen, said he had undergone the radical surgery, called a sleeve gastrectomy, for his own health and "to better serve" his electorate.

"Now I can only eat small portions not exceeding about five semi-heaped tablespoons of food at any given time," he said.

"It's radical but good health is worth it and I have not been the picture of good health in a long time."