This won’t come as a surprise to most readers, but…sugar is bad for you. But if you think drinking diet soda will keep you from gaining weight and becoming diabetic, think again.
A new study published in the British Medical Journal (BMJ) shows that people don’t have to be overweight to develop Type 2 diabetes. Just chugging a single sugary drink ups the risk of the disease in even lean individuals. 
Researchers say that people who routinely consume one sugar-filled beverage a day – be it soda, iced tea, or any other sweet drink – increase their risk of Type 2 diabetes by 18% over the course of a decade compared with those who avoid sugary beverages.
The scientists reached this conclusion by culling data from 17 previously published studies that had analyzed the association between sugary beverages and diabetes risk.
Even after researchers adjusted their estimates for body weight, they found that thin or normal-weight people who drink sugary beverages daily face a 13% increased risk of diabetes.
“So even if people are lean, if they continue consuming sugar-sweetened beverages, they have a greater likelihood of developing Type 2 diabetes,” study author Fumiaki Imamura, of the University of Cambridge School of Clinical Medicine, told us.
Due to the observational nature of the studies Imamura analyzed, the scientists could not prove cause and effect, but rather a correlation. Yet, the science surrounding diabetes and sugary drinks is well-established and well-documented, and researchers say they understand how the biological mechanisms of too much sugar can tax the endocrine system.
Is Diet Soda any Better?
Many diabetics turn to diet beverages to quench their thirst and satisfy their sweet tooth, but artificially sweetened drinks, unfortunately, may not be much safer. The new BMJ study uncovered a potential link between the products and Type 2 diabetes, as well as fruit juices, but the scientists lacked the evidence to make a solid determination. 
The association between diet drinks and diabetes has existed for many years. In 2005, the UT Health Science Center in San Antonio released the statistics from its community-based, quarter-century-long epidemiologic study which found that the more diet sodas a person drinks, the more likely they are to become overweight or obese.
“On average, for each diet soft drink our participants drank per day, they were 65 percent more likely to become overweight during the next seven to eight years, and 41 percent more likely to become obese,” said Sharon Fowler, M.P.H., faculty associate in the division of clinical epidemiology in the Health Science Center’s department of medicine.
“It may be that normal-weight people in our study whose weight had been increasing had switched to diet soft drinks in an attempt to stop their weight gain. That’s a very real possibility. Another is that drinking soft drinks, either regular or diet, is part of a lifelong ‘Obey your thirst’ nutritional pattern that sets a person up for weight gain later in life. Whatever the case, our results definitely raise more questions than they answer.”