Fructose is distinct from other sugars in its ability to cause intracellular ATP depletion, nucleotide turnover, and the generation of uric acid. Uric acid is generated via fructose due to its rapid phosphorylation (to fructose-1-phosphate) in the liver, leading to a rapid drop in free phosphate and ATP.  This drop in ATP leads to the stimulation of adenosine monophosphate (AMP) deaminase which deaminates AMP to produce IMP, which is subsequently converted to uric acid (A15346). Uric acid is normally an anti-oxidant but without sufficient amounts of ascorbic acid (vitamin C) present in the plasma, it functions as a pro-oxidant. Because many soft drinks and foods that are sweetened with high fructose corn syrup do not contain vitamin C, the resulting uric acid can lead to a number of harmful effects, including gout, chronic inflammation, hypertension, increased adiposity, fatty liver disease and obesity (A15346).  Many studies have shown that elevated uric acid levels are associated with several metabolic and cardiovascular conditions, including diabetes and coronary artery disease (A15346). Elevated serum uric acid has also been shown to be the most reliable predictor for the development of hypertension and incident renal disease (A15347) as well as fatty liver disease (A15348). Fructose-induced uric acid generation also causes mitochondrial oxidative stress that stimulates fat accumulation independent of excessive caloric intake (A15349). Several studies have demonstrated that oxidative stress is one of the earliest phenomena observed in vascular, renal, liver cells and adipocytes exposed to uric acid (A15347). High fructose consumption is also associated with more severe depletion of liver ATP, which may impair liver "energy balance”. High-fructose beverages have also been shown to lead to lower circulating insulin and leptin levels, and higher ghrelin levels. Since leptin and insulin decrease appetite and ghrelin increases appetite, some researchers suspect that eating large amounts of fructose increases the likelihood of weight gain.