Most juicing methods remove the fruit fibre so you are left with a very sugary drink that sometimes doesn’t even have any nutrients left because the vitamins and antioxidants have not survived the pasteurisation process.
Bottled smoothies tend to be very sugary too as they are diluted with apple or grape juice but contain a bit more fibre from crushed berries and bananas. Fresh juices do contain more vitamins, minerals and antioxidants but try to use a powerful blender that crushes the fibre (although some research states that highly processed fibre does not have the same modulating effect on blood sugar levels as that found in whole fruit) and if you feel adventurous, add some vegetables to it such antioxidant powerhouse kale, beetroot, parsley, cucumbers, wheatgrass, etc.
The UK Health Authorities recommend that juice is consumed in moderation specially by children and state that only a small glass (150ml) counts towards your 5-a-day, although there is raising demand for juice to be removed from the 5-a-day list because fibre-low processed juice should not be counted as a portion of fruit. I totally agree.
I am not a fan of processed juices even those from the chiller cabinet or labelled organic, they have little goodness in them despite having had synthetic vitamins added to justify all that sugar. If you do drink them, ensure you have them with non-sugary foods to protect your teeth and also buffer the glucose effect on your blood sugar levels.
For children, always dilute juice with plenty of water for the same reasons and limit it to once a day, juice should not be a child’s main drink regardless of how much they like it. Also, read the labels and look for juices not made from concentrate and that do not have any additives like sugar, corn syrup, HFCS, inverted sugar syrup, E numbers, colourings and artificial sweeteners.
The best you can do is to make you own juice, with fresh fruit and vegetables in a very high power blender that will not waste all that gut-friendly fibre and never ever add any sweeteners to it. I’d encourage you to add some protein-rich nut butters, fibre-rich oats, antibacterial coconut milk, good fats from milled seeds, etc to turn your juice into a nutritionally packed smoothie.