Using an artificial, no-calorie sweetener rather than sugar may make it tougher, not easier, to lose weight, according to researchers in the US. Scientists at Purdue University in West Lafayette, Indiana, studied rats that were fed food with the artificial sweetener saccharin and rats fed food with glucose, a natural sugar. In comparison to rats given yogurt sweetened with glucose, those that ate yogurt sweetened with saccharin went on to consume more calories and put on more weight and body fat.
The researchers said sweet foods may prompt the body to get ready to take in a lot of calories, but when sweetness in the form of artificial sweeteners is not followed by a large amount of calories, the body gets confused, which may lead to eating more or expending less energy than normal. “The data clearly indicate that consuming a food sweetened with no-calorie saccharin can lead to greater weight gain and adiposity than would consuming the same food sweetened with high-calorie sugar,” researchers Susan Swithers and Terry Davidson wrote in the journal ‘Behavioral Neuroscience’. Other artificial sweeteners such as aspartame, that also taste sweet but do not lead to the delivery of calories, may have similar effects, the researchers said.
“Animals may use sweet taste to predict the caloric contents of food. Eating sweet non-caloric substances may degrade this predictive relationship,” the researchers wrote. “With the growing use of non-caloric sweeteners in the current food environment, millions of people are being exposed to sweet tastes that are not associated with caloric or nutritive consequences,” the researchers added.
The research drew criticism from the food industry. “This study oversimplifies the causes of obesity,” said Beth Hubrich, a dietitian with the Calorie Control Council, an industry association representing companies that make low- and reduced-calorie foods and beverages. “The causes of obesity are multi-factorial. Although surveys have shown that there has been an increase in the use of ‘sugar-free’ foods over the years, portion sizes of foods have also increased, physical activity has decreased and overall calorie intake has increased,” Hubrich added.