Diet sodas may actually make you fat
Diet sodas and other sugar-free drinks may actually contribute to the risk of obesity, according to research published today in the journal Trends in Endocrinology and Metabolism.
In a review of the research, a leading professor of psychology and neuroscience says that soft drinks with non-caloric sweeteners, instead of high-energy natural sugars, may actually cause negative effects on the metabolism if consumed frequently.
"Frequent consumption of high-intensity sweeteners may have the counterintuitive effect of inducing metabolic derangements," says Professor Susan Swithers.
After examining the research, Swithers suspects that artificially-sweetened diet drinks containing aspartame, sucralose and saccharin may actually have the opposite effect of reducing obesity by instead increasing the likelihood of:
• Excessive weight gain
• Metabolic syndrome
• Type 2 diabetes
• Cardiovascular disease.
Indeed, nearly 30 percent of American adults consume artificial sweeteners, as well as approximately 15 percent of all American children age 2 and over. Those percentages reflect approximately twice what Americans consumed in 2000, according to a study published by the American Society for Nutrition last year.
"The concern that these non-caloric sweeteners might not be healthy is a message that many people do not want to hear, especially as the prevalence of artificial sweeteners increases," says Swithers.
Nevertheless, the food industry continues to flourish from sales of products containing artificial sweeteners, while the healthcare industry continues to battle the increase in obesity and other chronic diseases related to it, including diabetes and heart disease.
Accordingly, Swithers is calling for greater scientific understanding – something she says needs to reach all the way up to governments and politicians.
"When it comes to making policy decisions, it's more important than ever that the science is considered, and that the public understands what the science says in order to help them make the best health decisions," she explains.
As the nation saw recently when New York’s Mayor tried to limit the size of sodas sold to consumers in an effort to combat the rise in obesity – only for it to end up being rejected – wanting and accomplishing such goals can be more difficult than anticipated. Moreover, the notion of regulating diet sodas isn’t even considered because diet drinks are perceived to be “healthy”.
Still, Swithers believes the science should be bringing a change in this perception; thus, she basically proposes that regularly consuming sweeteners results in people having "weaker responses to sweet tastes."
According to Swithers, people have brain-stimulating taste responses to artificial sweeteners, but the additives then fail to deliver caloric energy to the body. Using the analogy of "Pavlovian conditioning principles," she says that the counterintuitive effect of sweeteners on weight gain may be explained by "weakened learned responses" to food and drink.
This effect may come from "non-calorific sweet tastes that are not accompanied by typical and expected post-ingestive consequences such as post-prandial release of insulin, GLP-1, orGIP, or activation of brain regions sensitive to energy or reward," she adds.
SOURCE: 1. Trends in Endocrinology and Metabolism, “Artificial sweeteners produce the counterintuitive effect of inducing metabolic derangements”, Susan E. Swithers (July 11, 2013). 2. American Society for Nutrition, “Low-calorie sweetener consumption is increasing in the United States”, (published August 1, 2012), doi: 10.3945/ajcn.112.034751 Am J Clin Nutr September 2012 vol. 96 no. 3 640-646.