Eat fat and lose weight?
Updated: Wed, Jun 20 1:37 PM EDT

ROTTERDAM, June 20 (Reuters) - After years of being taught eating fat is bad, will Americans be convinced to stop feeling guilty?

Will they believe they can throw out bland non-fat products and bulk up on fried foods and rich salad dressings?

That's the dilemma of a joint venture planning to market a new vegetable oil, already on sale in Japan, that helps people shed pounds.

The cooking oil contains diacylglycerol (DAG), which scientific studies have shown to cause a 50 percent increase in weight loss, a conference in the Netherlands heard on Wednesday.

Company officials are worried, though, that the new product could be a tough sell after decades of health officials linking fat consumption to heart disease.

"It's going to be a difficult market proposition. We have been saying fat is evil, it makes you fat, it causes heart disease," said Gary Miller of agribusiness giant Archer Daniels Midland.

ADM said last week it had formed a joint venture with Japanese company Kao Corp, which developed the product and launched it in Japan in 1999.

The oil, marketed as Healthy Econa Oil, has become a hit in Japan, becoming the best selling cooking oil in financial terms, with $100 million in sales last year.

It is sold at a premium, equivalent to the price of olive oil, said Miller, senior vice president of science and business development for ADM's Nutraceutical Division.

DAG, processed from rape (canola) and soy oils, helps people lose weight by being burned as an energy source instead of being directed to body tissues as layers of fat, like other edible oils.

A pilot plant for the product is due to be completed in November, but the U.S. launch of the product is still a couple of years off, Miller said.

Officials are considering putting the active ingredient in other food products since Americans do much less home frying of foods than the Japanese, he added.

The product is not suitable for deep-fat frying in restaurants since it cannot be reused over long periods of time, Miller said.

Benecol, another food brand marketed by Finland's Raisio, contains stanol ester which lowers cholesterol levels in the consumer.