There are more than calories to worry about when it comes to sugar.

Swiss researchers have found even moderate amounts of added sugar double the body’s fat production in the liver.


Too much sugar is not healthy but some justify it by thinking their activity levels will make up for the added calories. However, added calories is only part of the problem as Swiss researchers have found even moderate amounts of added sugar double the body’s fat production in the liver.

Researchers at the University of Zurich and the University Hospital Zurich wanted to know more about how even moderate amounts of sugar can affect test participants as fat production in the liver can lead to diabetes and non-alcoholic fatty liver disease. Scientists hope the growing problem can be addressed through experimentation-based education and published their findings in the Journal of Hepatology.

Data in Switzerland points to the average citizen consuming an average of 100 grams of sugar per day while the American Heart Association estimates the average American consumes about 77 grams per day. Research shows those numbers are too high to be sustained on a consistent level without serious health consequences.

"Eighty grams of sugar daily, which is equivalent to about 0.8 liters of a normal soft drink, boosts fat production in the liver,” said study leader Philipp Gerber. “And the overactive fat production continues for a longer period of time, even if no more sugar is consumed."

Researchers recruited 94 people for the double-blind, randomized trial which lasted seven weeks. The group was divided between those who, in addition to their normal diet, were assigned 80 grams of sugar-sweetened drinks containing either fructose, glucose or sucrose, which is table sugar derived from a combination of fructose and glucose. The control group avoided sugar-sweetened beverages.

The calorie intake was similar between the groups which researchers theorize is because the satiety offered by the sugar kept those participants from consuming extra calories. Researchers used tracers to track the food as it moved through the body to analyze the effects of the sugary drinks of lipid metabolism.

"The body's own fat production in the liver was twice as high in the fructose group as in the glucose group or the control group—and this was still the case more than twelve hours after the last meal or sugar consumption," Gerber said. He found sucrose boosted fat synthesis a little more than fructose alone which was surprising since he assumed fructose was thought to be the biggest contributor.

The World Health Organization recommends daily sugar consumption be limited to as low as 25 grams per day. "But we are far off that mark in Switzerland," Gerber says. "Our results are a critical step in researching the harmful effects of added sugars and will be very significant for future dietary recommendations."

Click here to read more in the Journal of Hepatology.

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