In the eye-opening documentary Fed Up! (2014) it is claimed that fruit juice is as unhealthy as soda, but I missed a good explanation as to why it is unhealthy while fruit, which it is made from, is good.

I found a possible explanation in an article published in the BMJ:

“the relatively high glycemic load values of fruit juices along with reduced levels of beneficial nutrients through juicing processes (for example, the glycemic load values per serving are 6.2 for raw oranges and 13.4 for orange juice, and fibre levels per serving are 3.1 g and 0.5 g, respectively) may explain the positive associations between fruit juice consumption and risk of type 2 diabetes. Moreover, the difference in the viscosity of foods is also an important factor affecting postprandial blood glucose dynamics. Fluids pass through the stomach to the intestine more rapidly than solids even if nutritional content is similar. For example, fruit juices lead to more rapid and larger changes in serum levels of glucose and insulin than whole fruits.”

I’m still not satisfied, as there are a whole range of different juices and smoothies, and some might have high levels of fibre and low glycemic levels. What should I look for on the label to decide how bad a beverage is? And if fiber is so important for how the sugar is digested, does it help to eat bread when drinking juice?