''A great deal of luck,'' is what he puts it down to.

Maybe. But hard work and ambition would have to be in the mix to head a Fortune 500 company. And plenty of both.

Mr Bryant, 46, is the US-based president and CEO of the global Kellogg Company, appointed to the post in January last year and earning a package of about $7 million a year.

He runs the business from the Kellogg world corporate headquarters in Battle Creek, Michigan, otherwise known as Cereal City. The Kellogg family founded the business there in 1906, the company creating such iconic products as Corn Flakes, Pop-Tarts, Nutri-Grain and Fruit Loops.

Kellogg products are now sold in 180 countries. Last year the company turned over revenue of almost $12.4 billion. More than one billion packets of cereal are sold each year in the United States alone.

Mr Bryant, who was educated at St Edmund's College in Canberra from grade five to year 12, is actually the second Australian to be chief executive officer of Kellogg, taking over from Queenslander David Mackay.

''It's an honour,'' he said from his Battle Creek office.

''It's a $13 billion company with 30,000 employees and operating in just about every country in the world. It's a fantastic company.''

Born in Brisbane, Mr Bryant is the second child of Bruce and Joy Bryant. His older brother David still lives in Canberra, working at the Australian Tax Office. Younger sister Shar-Maree is a teacher in Melbourne.

The family lived for a while in Penrith before they settled in Canberra, when Mr Bryant was about seven (he also went to St John Vianney's Primary School in Waramanga).

Bruce, a public servant, died in 1988. Joy, who worked for Australia Post in Canberra, still lives in Tuggeranong.

Mr Bryant's wife Alison (nee Bogg) was born and raised in Canberra.

The couple both studied at the Australian National University. In the United States, the Bryants live in Kalamazoo, not far from Battle Creek, with their six children aged from 16 to four.

''We still have deep roots in Canberra,'' he said. ''I probably visit Australia once a year for work and I always make the side trip to Canberra.''

While the company is focused on upping its falling sales by means such as targeting the emerging middle-class of China and India, Mr Bryant believes Kellogg is about more than dollars and cents.

He points to its long philanthropic history, with the W.K. Kellogg Foundation the company's largest shareholder. More than 20 per cent of all the company's dividends are distributed to the foundation, which has a focus on programs to help vulnerable children. Last year, Kellogg paid more than $130 million in dividends to the foundation.

''There's a higher calling, if you like, with a company like Kellogg, [for] which I don't think we always get the benefit of the doubt in Australia,'' Mr Bryant said.

''I think Australians have a certain question mark over US companies. But the reality is companies are just collections of people and people are actually trying to do the best they can.

''I think the tall poppy [syndrome] is a reality in Australia and it's not so much in the US. In fact, in the US success is aspirational. In Australia, success is something you don't really talk about.''

So how does a kid from Kambah get to run the Kellogg Company?

''I didn't know what I wanted to do when I went to ANU. I did a commerce degree, because that's what I got into,'' he said, Australian accent intact.

''I remember graduating from ANU thinking, 'I want to be a chief financial officer of a public company', without knowing what that meant, and went off to the real world and really enjoyed business at the end of the day.''

The quietly spoken Mr Bryant joined the Kellogg Company in 1998. He was its chief financial officer by the time he was 35. There was some serious determination in this Australian-on-the-rise. ''In some respects I quite deliberately went about my career to make myself a very good CFO,'' he said.

''So I spent five years with Deloitte and have a good background in accounting. And I went to business school in the States [the Wharton School of the University of Pennsylvania].

''I then did about four or five years in strategy consulting and then I actually joined Lion Nathan for about a year, and really enjoyed the company. But Kellogg gave me an offer I couldn't say no to. Kellogg was my client when I was consulting.''

It was the then Kellogg chief executive officer Carlos Gutierrez, also the secretary of commerce during the George W. Bush presidential administration, who lured Mr Bryant to the company.

''Kellogg was looking for someone to help run their strategy group in the US and so they asked me to join the company, which I did. And then about a year later they disbanded the group and I found myself in finance. Over the following two years, they fired all of my bosses so I became CFO,'' he said, allowing him a little chuckle over that stroke of luck.

While the Kellogg Company is a corporate legend, its products also attract their fair amount of detractors. In Australia the lobby group The Parents' Jury has put Kellogg's in its Hall of Shame, alongside McDonald's. Last year it awarded the Shame Award for Pester Power to Kellogg's LCMs, for ''TV ads that convey to children that having an LCM bar in their lunchbox will make them popular in the playground''.

Mr Bryant is used to the flack.

''I'm very proud of the food that we make. It is a low-calorie, nutrient-dense food. Look at cereal, it's about 140, 150 calories for a bowl of cereal with milk. Nine out of 10 people don't get enough fibre in their diet and our cereals are a good source of fibre, good source of vitamins and minerals. It is a great way to start your day. It's hard to find a better alternative,'' he said.

''The one critique we have of some of our cereals is that they can be a little bit high in sugar. We've been reducing sugar and salt in our cereal for several years around the world [but] at the same time, if kids don't eat it or people don't eat it, then they're going to go for something else that is worse for them.''

Mr Bryant says ''Australia will always be home'' and he'd love to come back here. But his children are likely to want to stay in the US, so that's where he and his wife will remain. ''Life takes all sorts of lucky turns and I think you just have to take the risk and go with it,'' he said.