The CSPI say that apart from making people fat, those who overindulge in soft drinks are also more likely to develop diabetes and have decaying teeth.

The group want cigarette-style warnings on the drinks and say they are particularly needed to counter the growing number of young people who drink soda.

CSPI executive director Michael Jacobson says, that in the past, soda pop used to be an occasional treat, he also says that it is all calories with no nutrients.

Jacobson says that the latest government data from 2002 shows teenage boys drink an average of two 12-ounce cans of soda a day compared to about 1.33 cans for teenage girls.

However food and beverage industry groups have rejected the call for warnings, saying obesity has complex causes and packages already list calories and ingredients.

Susan Neeley, head of the American Beverage Association (ABA), says that individuals and not the government, are in the best position to make the food and beverage choices that are right for them.

The industry-funded Center for Consumer Freedom, along with other groups, says that regulating sodas would limit consumer choice.

Although some firms have reintroduced smaller packages, the CSPI says cheap prices and multiple-serving bottles, attract consumers.

According to Jacobson, government warnings are needed to encourage the public to follow a healthier diet, just as aggressively as the soft drink industry, the fast food industry and others push people in the other direction.

FDA officials and major food and drink companies, Coca-Cola, PepsiCo and Cadbury Schweppes, have as yet not commented.

He noted that bone fracture is a serious problem for elderly people, especially those with osteoporosis. Bone fracture is one of the leading factors in decreasing quality of life for the elderly. "Cancer and heart disease can kill you but bone fracture and arthritis make you miserable," he said. "Once a serious bone fracture occurs, then quality of life goes down. Less than one-third of elderly women who have a hip fracture return to previous function. More women die within a year of hip fracture than die after a heart attack. So it's a very serious problem and a lot of work has been done to develop good diagnostics. The leading diagnostic is bone mineral density."

Measuring bone mineral density is valuable because it reveals how much bone a person has left. The amount of an individual's bone mineral density peaks around age 30, then decreases for the rest of his or her life. By the time the person becomes elderly, very serious bone loss may have occurred.

"As if this weren't bad enough, it is also true that the materials properties of the bone decrease with age," said Hansma. "Not only is there less bone, but what exists is less strong. The cause of this is not well understood. Our research is aimed at understanding that."

Hansma noted that bone has been studied extensively since Galileo. "Galileo wrote a really nice paper about bone, describing why elephants need thicker bones than small animals." He said that a paper on bone is published every six minutes. And although bone is extensively studied, little is known about how it works at the molecular level. "Our paper is the beginning research on this."

Hansma and his colleagues at UCSB have pioneered the use of the Atomic Force Microscope (AFM) in looking at the nano-scale level of biological materials “ down to a billionth of a meter. Before the use of the AFM, it was impossible to see these tiny molecular structures.

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