Speaking to ABC Far North from the side of the Bruce Highway, Dr Boyd said obesity was Australia's number one health problem, and health professionals were just as prone to its effects as everyone else.
"We find ourselves sitting on one side of the consulting desk talking to people who've got obesity problems, and if we look as if we're not particularly fit ourselves [the message] doesn't ring too true," he said.
"Not only do we have obesity, but it is getting worse.
"There are no secrets, diet and exercise are the main ways to deal with it."
For the next 10 days Dr Boyd will be walking 30 kilometres a day, through rain, hail or shine, to reach his final destination.
On the way, he and his support driver, Des Burgess, will visit a number of the regional towns dotted along the Bruce Highway.
"We're hoping to catch up with some of our (medical practitioner) colleagues and anyone else that wants to stop and talk about the problem of obesity," Dr Boyd said.
"Obesity, diabetes, cardiovascular disease, high blood pressure, and then of course the increasing damage to hips and knees are all important [to talk about]."
He said more people needed to be aware of the problems a poor diet and a lack of exercise can have on long-term health.