TOYAKO, Japan -- Leaders of the Group of Eight are arriving this week in northern Japan to grapple with a raft of problems, from soaring food and fuel prices to African poverty and global warming, amid doubts about how much the annual pageant can achieve.

Britain, Canada, France, Germany, Italy, Japan, Russia and the United States will be joined during the meetings running from Monday through Wednesday at a luxury hotel in the lakeside resort of Toyako by heads of seven African states and major economies including China and India.

That makes this the largest such gathering since the event began more than three decades ago, when a cozier club of Britain, Germany, France, Italy, Japan and the United States met at the Chateau de Rambouillet outside Paris in November 1975 to discuss the oil crisis and a world recession.

The themes are familiar, but the scale of the summit, which draws huge media coverage, countless activists and sometimes-violent protests, has some charging that the event has gotten out of hand.

"The first summit was a very small affair. They got in a room, said they were facing a crisis, did a little horse-trading, and came up with a plan," said Robert Feldman, chief economist at Morgan Stanley in Tokyo.

"It has become something of a carnival ... and got away from the original intent, which was to sit in a room together -- the human side of negotiating and getting things done," Feldman said. "It's unwieldy, and it's not leading to a lot of results."

At the same time, the relative clout of the core group has shrunk. The G8 accounted for about 48 percent of world GDP in 1975, but by 2006 the G8's share had slipped to around 43 percent.

Over the same period, the share of five big emerging economies that call themselves the Group of Five -- China, India, Brazil, Mexico and South Africa -- grew to 27 percent from 12 percent, measured by the purchasing power of their currencies.

One reason for higher food and fuel prices is growing demand from such emerging economies, making it hard for the G8 alone to come up with solutions.

"The emerging markets have become a much more important part of total economic activity, but the monetary policies they are running are too easy. That is spurring inflation in these countries, and that tends to push up commodities prices," said Peter Morgan, chief Asia economist at HSBC in Hong Kong.

"In the 1970s it was the developed economies that were running too easy monetary policies, so they could address it. But now they are passive receptors of the inflation burst from emerging markets," Morgan said.

A Major Economies Meeting on Wednesday will bring together the G8, the G5 and Indonesia, South Korea and Australia -- a group that accounts for about 80 percent of the carbon dioxide emissions that cause global warming.

U.S. President George W. Bush is reluctant to agree to emission targets without big developing countries on board.

French President Nicolas Sarkozy is among those who advocate formally expanding the G8 to include China and others, although Japan, for one, is not keen to see its Asian rival join the club.

Sarkozy repeated the call for expansion on Saturday.

"I think it is not reasonable to continue to meet as eight to solve the big questions of the world, forgetting China -- 1 billion, 300 million people -- and not inviting India -- 1 billion people," he told a conference in Paris.

The problems to be tackled have also become increasingly complex and intertwined, further limiting what G8 leaders can do to solve them in three days of meetings and socializing.

Efforts to reduce dependence on oil and cut greenhouse gas emissions have led many countries, the United States in particular, to turn to biofuels.

That has, in turn, helped push up food prices, as has rising demand from emerging countries and volatile weather that many attribute to climate change.

Still, for all its warts, the G8 has fans.

"The fact that it became ritualized should not detract from the fact that there is one more alternative to yelling and screaming and fighting," said Andrew Horvat, a professor at Tokyo Keizai University. "If there was a crisis, and you had to create it, you couldn't do it. For people to yawn is to miss the point."