As I understand it, the process you describe is true of glucose but actually not fructose. Glucose gets absorbed into your blood, causes your pancreas to start

As I understand it, the process you describe is true of glucose but actually not fructose. Glucose gets absorbed into your blood, causes your pancreas to start releasing more insulin into the blood, which causes basically all the cells in your body to start absorbing glucose. Fructose on the other hand can only be processed by your liver, so all the fructose you eat just kind of queues up for your liver to process it. It doesn't cause you to release insulin so it has a low glycemic index. Your liver can convert fructose to glycogen and then to glucose to feed your cells if you don't eat any carbs or glucose. But if you already have more than enough carbs/glucose, your liver instead converts the fructose to fat and stores it. This can lead to fatty liver and somewhat interestingly can also lead to insulin resistance which then makes you worse at processing glucose. Alcohol also gets processed exclusively in your liver and can cause fatty liver, so it is true that juice and beer can do a similar kind of damage. Anyway, on the bigger point I 100% agree that juice is bad for you. It's sad to see it so often touted as healthy. EDIT: One thing I do wonder about, people always point to fiber as a reason why fruit is ok but fruit juice isn't. It seems like it would be a lot easier to get people to start taking fiber supplements than to stop eating sugar, so why don't we ever hear that advice?