Morning Banana Diet, Anyone?

Diets hailing bananas as a new superfood that assists weight loss is fueling a
boom in banana sales in Japan

The Morning Banana Diet regime is simple: A banana (or as many as you want) and room temperature water for breakfast; eat anything you like for lunch and dinner (by 8 p.m.). A three o'clock snack is okay, but no desserts after meals, and you have to go to bed before midnight. Sumiko Watanabe, a pharmacist in Osaka designed this stress-free diet to help increase the metabolism of her husband Hitoshi Watanabe, who had been rather overweight. In due course, Mr. Watanabe lost 37 pounds and introduced the diet on mixi, one of Japan's largest social networking services. Morning Banana Diet books published since March have sold over 730,000 copies, and some have been translated and published in South Korea and Taiwan. The diet became even more popular after a TV program featured a singer who had lost 15 pounds in just six weeks. It was literally the day after that program aired that the shortage of bananas first became evident. "Bananas suddenly flew off the shelves, there was a 70%-80% increase in weekly sales compared to the same period last year," says Takeshi Ozaki, a spokesperson of Life Corporation that runs 201 supermarkets throughout Japan.

Professor Masahiko Okada of Niigata University School of Medicine questions the hype around the banana diet. The human body has three essential nutrients: carbohydrates, fat and protein, she says, and "the golden rule is to balance these three nutrients and a daily calorie intake. Once you understand that, you don't have to be swayed by the fad diet any more, whether it is a konnyaku (alimentary yam paste) or a banana diet." But a nation prone to dieting fads often ignores such sober advice.

According to Ministry of Finance, Japan's banana imports were 970,000 tons in 2007, mostly from the Philippines. "It takes from 10 to 15 months to harvest bananas, so it is not at all easy to meet a sudden increase in demand," says Dole's Ohtaki. Dole Japan is trying to make up the shortfall by negotiating distribution deals with Dole corporations in other countries. Supplying the spike in demand will be lucrative, because banana prices in Japan have risen about 20% as a result of supply shortages that have coincided with the diet fad.

Bananas are hardly the first fad diet to create shortages in Japan's consumer markets. During the 1970s, there were similar runs on black tea fungus, oolong tea and konnyaku; during the 1980s it was baby formula, banana and boiled egg; then, in the '90s, came apple, nata de coco, cocoa and chili pepper; and during this decade black vinegar, carrot juice, soy milk, beer yeast and toasted soybean flour (kinako). Last year's fermented soybean (natto) diet emptied supermarket shelves. Based on experience, Horiuchi predicts that the banana boom will last only another month or so. "In the past, there were all kinds of hit diets. But they never last, do they? So, we don't really want to end up with an uncontrollable banana surplus."