Fructose is a signal, not a calorie
Chris's argument is that fructose does something no other sugar does. Its first metabolic step is unregulated, so a large enough dose burns through the cell's ATP and leaves uric acid behind. Research associates that burst with mitochondrial stress and a shift toward energy conservation. Chemaine's framing lands the same place: it is a survival mechanism trying to keep you alive, not a defect.
