THE latest fat and sodium-laden burger to hit the hips has no bun and is pure deep fried chicken meat, bacon and two slices of melted cheese.

Almost two hours of walking - or about an hour of intense physical activity - is needed to burn off KFC's Double Down, according to nutritionist and author Susie Burrell.

"Say an hour on a treadmill and that's without the fries and the drink that goes with it," Ms Burrell said.

"It's gross overconsumption because it is above and beyond a regular burger. The other (factor) is that it teaches Australians that it is normal."

At 1939 kilojoules (kJ), the 212g KFC Double Down original recipe has 32.3g of fat but pales in comparison with the 232g Double Down Zinger at 2515kJ and 35.7g.

McDonald's Double Quarter Pounder hits a massive 3560kJ, Macca's Grand Crispy Chicken is in the ballpark for a poultry meal at a not-so-paltry 2510kJ. The average daily adult intake is about 8700kJ.

Worst of all is Hungry Jack's Ultimate Double Whopper, which delivers a whopping 5085kJ, laden with 80.5g of fat.

Brisbane construction worker Jason McDonald said because of concerns about the nutritional value of KFC's Double Down, he wouldn't consider eating it as an everyday food.

"I wouldn't eat it all the time," he said.

"It's a special treat. The kids would like it more, I think."

Fellow worker Peter O'Neill was more concerned about the $7.95 price tag than the nutritional value of the meal.

"It's chicken chicken's all right," he said. "It tastes good but it may be a bit dear."

When it was launched in the US last year, the Double Down caused a storm of controversy at a time when First Lady Michelle Obama was driving a campaign to cut the nation's rampant obesity.

One Chicago Tribune writer called the Double Down a "meat-glorb".

The bunless burger has already sold 15 million units across the US and Canada.

Ms Burrell said it was disappointing to see such a high-fat product released when most fast-food chains were offering healthy options, backed by the Heart Foundation tick.

"It's disappointing because large companies, especially fast food companies, are so keen to market health campaigns," Ms Burrell said.

KFC, which has no Heart Foundation ticks, is marketing the burger as one of the "manliest" burgers around.

It said the Double Down should be enjoyed as an occasional treat and as part of a balanced lifestyle.

Originally published as Double downer on KFC bunless burgers