Mutt

i'm only half kidding, I've had this theory my whole life about diet soda/pop - I've never known ANYBODY with any weight problem who drinks diet soda to ever lose any weight and most get heavier. I'm sure you've had family or friends who are very overweight freak out when you don't have a diet soda for them and you're thinking 'um.....you're 300 pounds, you eat everything in sight .............'

http://www.canada.com/vancouversun/n...6e225ac&k=3814

Ditch the diet soda if you're trying to lose weight

Sugar-free sweeteners may make you fat, new research suggests.

In a study to be published today, American researchers found that rats fed yogurt sweetened with zero-calorie saccharin later consumed more calories and gained more weight and body fat than rats fed yogurt sweetened with sugar.

The finding may help explain why rates of overweight and obesity have increased dramatically over the past 30 years along with the growing use of artificial sweeteners by millions of people, the researchers say.

The data clearly indicate that consuming a food sweetened with no-calorie saccharin can lead to greater body-weight gain and adiposity (fat tissue) than would consuming the same food sweetened with a high-calorie sugar," Purdue University psychologists report in today's issue of Behavioral Neuroscience.

The study was done in rodents, not humans. But recent epidemiological studies have suggested an association between diet pop and a higher risk of obesity and metabolic syndrome - a cluster of risk factors for heart disease and diabetes that includes excessive belly fat, high blood pressure and increased blood sugar.

"If you look on the human side, there have been a number of studies and what they've suggested is kind of all over the map," said Susan Swithers, lead author of the new study. "One of the questions has always been, why is it so hard to find any consistent answer to this problem?"

In the new research, one group of rats was fed plain, unsweetened yogurt on some days, and yogurt sweetened with glucose - a sugar with 15 calories per teaspoon, the same as table sugar - on others. A second group had yogurt sweetened with saccharin alternated with unsweetened yogurt.

After five weeks, the rodents fed the artificially-sweetened yogurt gained more weight and were fatter than the other animals.

A second study revealed that the rats fed yogurt sweetened with saccharin were eating more chow.

"They're actually getting fewer calories from the yogurt than the other animals, but they're eating extra chow, they're eating more," Swithers said.

The researchers measured changes in core body temperature. When we eat a meal body temperature increases as metabolism "revs us," according to a background release issued with today's study. But the rats fed artificially-sweetened yogurt didn't show as big an increase in core body temperature.

"It looks like the other reason the other animals might have gained the extra weight may be because they're not burning up as many calories," Swithers said.

One theory is that, when we eat something sweet, the body thinks it's about to take in calories and certain physiological responses kick in. But if there aren't a lot of calories, the system gets confused. The result? People may eat more, or burn fewer calories than they otherwise would have.

Think of it as Pavlov's dog, Swithers says. "You ring a bell and the dog salivates, even if there's no food there.

"That's a response that anticipates the arrival of food. There are lots of physiological responses that can get conditioned and we think that some of these physiological responses may contribute to how you use the calories and when you stop a meal."

"Maybe the next time the animal says, well, last time I didn't get very many calories, I better eat more because those calories aren't going to show up," Swithers said.

She says it's conceivable that people who consume artificially-sweetened foods and drinks "might be undermining some of these unconscious or automatic processes."

So, should people stop drinking diet pop?

"We don't know how long-lasting or persistent this effect is," Swithers cautioned. But she says people who are drinking diet soft drinks in an effort to lose weight should make an extra effort to count total calorie intake.

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