ISLAMABAD (Online)- While candy consumption has risen slightly over the past three decades, it is drowned by the trend in sugary drinks. Today, the biggest single source of calories in the diet is fizzy soft drinks. The average teenage boy will get 15 teaspoons of sugar a day just from these drinks, according to one report. "It's shocking because it's all empty calories," said Dr. Caroline Apovian, director of the Nutrition and Weight Management Center at Boston University School of Medicine. Medical researchers watching this trend say the growing fondness for sweetened drinks may be one of the major forces behind children's rates of obesity, diabetes and tooth decay. It also may set up children for a lifelong increased risk of osteoporosis. The problem is not just what children are drinking but what they are not drinking. In the 1970s, children chose milk - a source of vitamins, protein and calcium - over sweetened drinks by almost 4 to 1. By the late 1990s, in the latest data available, soft drinks had almost caught up with milk. Any kind of excess sugar could be detrimental to health, but sugar from beverages creates unique concerns, doctors say. "The thing about the drinks is that they are so insidious," said Dr. Sarah Blumenschein, a pediatric cardiologist with UT Southwestern Medical Center at Dallas. With candy, she said, "most kids will stop eating. When they're full, they stop. With drinks, they often won't."  Hot, thirsty children, she said, "can load up and drink themselves a couple thousand calories a day." This may occur in part because the liquid calories in those ever-growing servings do not seem to set off feedback mechanisms of fullness. Food, even a candy bar, normally activates hormones that help the body feel full. But experiments suggest that beverages may bypass those triggers. "When we consume a calorie as a beverage, we don't adjust our food intake," said Dr. Barry Popkin, an obesity researcher at the University of North Carolina at Chapel Hill. And some scientists suspect that the sweetener used in those drinks since the 1970s - high-fructose corn syrup - may be metabolised by the body differently than glucose, the main energy source from food. Last year, Dr Popkin and his colleagues wrote in the American Journal of Clinical Nutrition that "soft drink consumption may be an important contributor to the epidemic of obesity, in part through the larger portion sizes of these beverages and through the increased intake of fructose from high-fructose corn syrup and sucrose." For example, one study published in 2001 followed 548 Massachusetts schoolchildren for 19 months, trying to see whether their weight was associated with drink preference. They found that each additional daily serving of any sugar-sweetened beverage, including fruit drinks, increased the likelihood of obesity in a child by 60 percent. Dental experts, for their part, worry that sweet drinks stand to threaten years of improvement in pediatric dental health. Studies have suggested that sugar in liquids may in some ways have a bigger effect on teeth than its solid counterpart. Some dentists speculate that this may be because sodas have not only sugar but also acid that might erode a tooth's protective enamel. Dr Teresa Marshall of the University of Iowa, who has conducted several studies on the effect of beverages on health, also believes it has something to do with the way drinks are consumed. Foods are eaten at once and washed down. Children often have sweet drinks between meals while doing other things. "If you're carrying around a beverage for a period of time, you have a constant exposure to the sugar," Dr. Marshall said. Experts note than any of these health problems have complex roots. People are gaining weight because they are consuming more calories than they used to and aren't burning them off before they are stored on hips, waists and thighs. This is not solely the fault of sugar. "What we can't prove is that it's the soft-drink consumption that has caused the obesity epidemic," said Dr. Apovian from Boston University, "but we can say the two have risen in parallel." Secondhand smoke increases heart risks  The average nonsmoker walking into a smoke-filled room might not think short-term exposure to cigarette smoke will affect them. But a new study suggests that even small amounts of secondhand smoke can cause life-threatening changes to a nonsmokers' circulatory system. And while the immediate effects of this exposure are reversed within a few hours, exposure to secondhand smoke over longer periods of time can have devastating consequences to the heart, including an increased risk for heart attack, researchers warn. "Secondhand smoke is even worse than we thought," said co-researcher Stanton A. Glantz, a professor of medicine and longtime antismoking advocate at the University of California, San Francisco. "It increases the risk for an acute coronary event like a heart attack or long-term development of atherosclerosis," he added. Chronic exposure to secondhand smoke is about 80 percent as deleterious to health as being a pack-a-day smoker, Glantz said. "The cardiovascular system is exquisitely sensitive to the toxins of secondhand cigarette smoke. Most of the toxic effects of secondhand smoke occur within five minutes of exposure," he noted. In their study, Glantz and his colleague Dr. Joaquin Barnoya, an assistant adjunct professor of epidemiology at UCSF, reviewed the existing medical literature on the effects of secondhand smoke on the cardiovascular system. They looked at 29 studies published since 1995 that compared the effects of secondhand smoke with the effects of active smoking. Their report appears in the May 24 issue of Circulation. Glantz and Barnoya found there is sufficient evidence that key aspects of cardiovascular function, including clotting, the ability of blood vessels to change size, arterial stiffness, atherosclerosis, oxidative stress, inflammation, heart rate variability, energy metabolism, and severity of heart attack are all sensitive to toxins found in secondhand smoke. "The effects of even brief (minutes to hours) passive smoking are often nearly as large (averaging 80 per cent to 90 per cent) as chronic active smoking," they wrote. "It doesn't take much to cause big effects," Glantz said. "If you already have compromised coronary circulation and go into a smoky environment, there is a substantial increase in your risk of an acute event." Barnoya believes the findings belie what the tobacco industry would have people believe. "The arguments from the tobacco industry have been that it is not likely that you can find such large effects in passive smokers, given the dose they get compared with the dose an active smoker gets," he explained. But nonsmokers are more sensitive to the effect of tobacco smoke than are active smokers, Barnoya said. "In some cases, the effects are as large or even larger than you see in an active smoker." The dangers of secondhand smoke are so great that Barnoya believes everyone should avoid it. "We should be fighting for smoke-free environments," he stressed. Other experts not involved in the study are unanimous in their agreement of the dangers of secondhand smoke. "Secondhand smoke disables and kills many people by virtue of its cardiovascular effects and also by virtue of its effects on the lung," said Dr. Norman H. Edelman, chief medical officer for the American Lung Association. Another expert sees secondhand smoke as an assault on the health of nonsmokers. "How can any society allow tobacco smoke to be imposed on innocent bystanders?" asked Dr. David L. Katz, an associate clinical professor of public health and director of the Prevention Research Center at Yale University School of Medicine. "We have clear, convincing evidence that those who smoke are swinging a big stick indeed at the noses of those of us who don't," Katz said. "While they should have autonomy over their choices, they should not have autonomy over ours. Smoking in public places does not stop where my nose begins and therefore, it should be banned. Not just by some states, but by all. This study will, I hope, help cultivate the political will to see that job is done sooner rather than later."