A Yale University food policy researcher says a tax on fatty foods can be a first step towards tackling obesity.
The comment comes as Fiji's interim government confirms it plans to follow Denmark in the imposition of a fat tax.
World leaders, including those from the Pacific, committed to taking action on surging rates of obesity-related illnesses at last month's United Nations General Assembly session in New York.
Dr Kelly Brownell says there are two problems with unhealthy food.
"It tastes really good and it acts on the brain in such a way that it keeps us wanting more of it. Plus the foods are the ones most heavily marketed by the industry because these are foods that people over-consume. So something needs to be done to change that incentive structure and changing the price could be one thing that could do that."
But Dr Kelly Brownell says no single government intervention such as a tax will reverse obesity trends.