Sugar type may be an independent risk for weight gain and disease.
I have been told for years that calories are calories and it does not matter from which source they come. This month, I found a study in a PubMed search and a review article from Science Daily that completely shoots this theory full of holes. The more I read, the more false this statement appears to be. I am not saying that calories do not matter, what I am saying is that the type of sugar you eat or drink does matter and may have effects by itself.
The study I am referring to is by Sangüesa and a group of researchers and was published in December of 2016 in Heart and Circulatory Physiology. This research looked at metabolism and vascular function in rats who were given supplemental sugar in the form of fructose and glucose over the eight weeks of the study. The results revealed that the sugar supplemented rats ate more calories than those that were not supplemented. Also, the fructose-fed rats had significantly more weight gain and worse vascular function.
Bottom line: More research is needed, but the results suggest that the number of calories consumed due to supplemented sweeteners and the type of sugar consumed may be independent risks for weight gain and disease or poor health. Even if it is not an independent risk from calories, the risk imposed by the type of sugar is in addition to the calories. The health conditions that might be of risk are diabetes, hypertension, heart disease, and stroke. I would certainly consider decreasing both fructose and glucose in your diet, but if you have sugar, I would choose glucose over fructose.