Sugar’s biggest rally in a decade isn’t convincing many of a sustained turnaround for the worst commodity in recent years.

London’s Sugar Week kicked off Monday on the back of raw sugar’s best weekly gain since 2008, a surge driven by a stronger currency in top producer Brazil. But it’s still one of this year’s worst performers, and there was little consensus among traders, brokers and analysts gathering in London that prices will climb much further. The cautious outlook is mainly down to India. Following a bumper harvest, the No. 2 producer is expected to boost exports, more than offsetting cutbacks in output elsewhere and ensuring yet another year of global surpluses. That’s happening as health concerns are curbing appetite for sugar, led by declining or stagnant consumption in western markets.