At least as far as the podcast goes, Richard Johnson, MD notes that the first enzyme in the metabolism of fructose (phosphofructokinase), is constitutive, that is it keeps causing the phosphorylation of fructose if there is any fructose around, and any high energy available phosphate; eg ATP, ADP, or AMP. The net result is free adenine that is metabolised to uric acid which promotes fat storage and inhibits mitochondrial function. The net result is an energy deficit in the cell, which signals the brain to consume more calories, leading to obesity, leptin resistance and metabolic syndrome. The uric acid also affects the kidneys, promoting hypertension.
On the other hand, Tim Podlogar a Research Fellow in Sports Nutrition at the University of Birmingham, in a podcast (I think it was Empirical Cycling), notes that as far as World Tour teams, fructose is essential, not only for getting up to 130 grams of carbohydrate/hr, and fructose seems to increase the rate of glycogen replenishment in recovery periods. I wrote Attia to try to clarify this, haven’t gotten a response.
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