Prof Dean, of the University of British Columbia, Vancouver, gave a public talk at Otago University this week focusing on ''Making New Zealand the healthiest country in the world''.
''It's not a big deal to make little changes,'' she said in an interview.
Prof Dean, who is a William Evans Fellow at the Otago School of Physiotherapy, said that, by international standards, many New Zealanders already enjoyed good health and wellbeing.
And the goal of the World Health Organisation - ''health for all'' - was within reach this century, provided the political will was there.
She urged people not to skip breakfast, or just make do with a cup of coffee.
Breakfast was a key meal, and she suggested starting the day with unrefined oatmeal, a lot more fruit and vegetables, and even a few walnuts.
She also urged a reversal of the usual daily hierarchy of food portion sizes- eating more at breakfast and a little less later in the day.
''Eat like a king in the morning, like a prince at lunch and like a pauper at dinner.''
New Zealand faced a looming epidemic of obesity and rising type 2 diabetes rates, but by walking more, and reducing fat, salt and sugar, people would make big differences to their health.
A huge amount of scientific research already showed the life-transforming benefits of improved diet and exercise, but many health professionals were ultimately not doing enough to communicate this to their patients.
If drugs had the same benefit - which they largely did not - and were not being prescribed by physicians, they would be ''disciplined and potentially lose their licence to practise'', she said.
The impact of healthy living was ''so glaring''.
Negative behaviour resulted in largely avoidable tragedies and even small positive habits could ''benefit health substantially''.
New Zealand ultimately faced some ''tough decisions'' on the obesity epidemic but a ''multilevel'' approach, including positive Government policies, could make a big difference, she said.
