I had a discussion with a friend of mine. He claimed that (processed) fruit juices from any organization (say Tropicana) are not at par with naturally occurring fruits, rather they are worse. He said that
Drinking fruit juice would cause it to be digested suddenly which would give a spike in blood sugar causing insulin to store it and making you hungry again. The point I am making is that the amount of glucose it will give you will not be equal to the amount of hunger it will kill. So even though you get the same amount of energy from a fruit juice and fruit, fruit will kill more hunger
But, AFAIK, there may be an argument about the negatives of processed food (or fruit juices), but polysaccharide breakdown has little to do with it. Whether I take one fructose molecule or two sucrose molecules or 4 glucose molecules doesn't change the molarity of glucose being absorbed by our bodies through digestion. How long it takes to break down the molecules into simple glucose doesn't affect total energy absorbed. After absorption, it does not matter how nor where the nutrients come from, the body maintains homeostasis and will handle everything just fine. So I think his "constant supply of energy" claim is fallacious. Also, Sugars in our diet go quickly into the bloodstream, which is great for athletes needing a quick boost in energy. However, it messes up homeostasis and the body will have to suddenly make a lot of insulin. That is the only problem with that, and that is the sole reason people are recommended to not do that.
My question is, is he correct? Because I had the belief that an ounce of orange juice from Tropicana would have more or less the same amount of nutrients an orange (of same quantity) will contain.