If ads for dietary supplements that discharge fat from the body seem too good to be true, it's because they are.

They are, however, effective in slimming consumers' pocket books.

That's what scientists say, and the government is convinced enough to put a stop to the exaggerated claims.

One such ad appeared on the Internet and television again and again. It claimed a ``scientific basis'' for the supplement's effects with convincing photos and simulations.

In one ad, the powdered supplement was dropped into a glass of water containing olive oil. Then, oily clumps formed and sank, implying similar results occur in the stomach.

``Even if you eat anything, as much as you want,'' another said, ``fats will be expelled.''

Ministry of Health, Labor and Welfare officials say they don't know how many fat-discharging supplements are on the market, but that the advertised effects are ``false'' or ``exaggerated.''

One diet-food manufacturer says the number ``easily surpasses 100.''

The ministry had the National Institute of Health and Nutrition test such supplements. Almost no weight loss was observed between rats that were given the diet foods and those that were not.

Sixty rats were put into 10 groups. One group was given only normal food for three weeks, while other groups were given food mixed with various doses of different fat-expelling supplements. The test was repeated. Researchers found 90 percent or more of consumed fats and carbohydrates were absorbed by the rats' bodies-in all 10 groups.

``We can surmise that the same thing takes place in the human body,'' said Kazuhiko Yamada, manager of the institute's Applied Food Research Division.

The findings have prompted the health ministry to crack down on irresponsible advertising. It is currently drafting guidelines under the Health Promotion Law to ban misleading ads for supplements claimed to discharge body fats.

The revision will be applied not only to manufacturers but also media, such as TV stations or magazines. It will carry a penalty of imprisonment for up to six months or a maximum fine of 1 million yen for those that ignore government orders to stop.

The diet-food industry has been anticipating the move. Some manufacturers have already trimmed the fat of exaggeration from their ads.

A company in Kyushu that sold 150,000 units of dietary supplements in six months since June 2003 deleted misleading illustrations from its Web site in October.

The maker is considering nixing the product altogether.

``We wanted the central or local governments to show us in advance what advertisements are appropriate,'' one of the company's officials complained.

A mail-order company in Tokyo has temporarily suspended the sale of fat-discharging diet foods.

``We are no longer able to sell the products with confidence,'' an official explained.

Physician Shuji Inoue, former director of the Japan Society for the Study of Obesity, welcomes the ministry's move.

``It is scientifically wrong to give the impression that phenomena that happen in a test tube will also happen in the body,'' he said.

An official of one supplement producer in Tokyo said his company stopped using test photos in its ads a year ago, apart from the ministry's move. But he added that the temptation to start using them was strong.

``The heating up of the whole industry had escalated our advertisements,'' he said.

The Japan Magazine Advertising Association checks up to 400 advertisements a year. Of them, 85 advertisements, or 24 percent, were for diet foods in fiscal 2003. In fiscal 2002, 116 advertisements, or 30 percent, were in that category.(IHT/Asahi: December 1,2004)