While you are in braces, you may have to forget some of your favourite foods for the duration of the treatment. This means that once the braces come off, you can get right back to munching them, but while the braces are on, they are off limits. Below I wish to mention some of the foods, in categories, that are off limits, and also provide a reason why they must not be eaten with braces. Hopefully this will avoid any and all confusion, and give satisfactory answers to what kinds of food cannot be eaten, and why.
Taffy, caramels, sticky candy
Sticky foods have a relatively big traction, and can remove and dislodge brackets from the teeth, or the wire can get stuck in it and can be pulled out of the bracket, too. Aside from this, it can stick on the device and the tooth surfaces as well, causing cavitation and gum disease, as this sticky mess cannot be removed and feeds bacteria as well. Gum, liquorice and other such things are also off limits, for the same reason.
Although healthy and delicious, raw veggies need to be foregone until the braces come off. This also includes bread with hard crusts and any fruits that are hard. The reason is that the hard surfaces may push the brackets off of the tooth, thus dislodging them and complicating treatment. However, if you chop them fine, make them into a smoothie, or find some creative way to liquefy them, fruits and veggies are always recommended.
If temperatures rise or fall very suddenly, they may cause problems for braces, which is why eating ice cold foods and piping hot beverages may be a bad idea. The teeth and the gums around them are very frequently sensitive during the course of orthodontic treatment, and the sudden change in temperature may be quite painful. The sudden change in temperature may also cause the tooth enamel to crack, and may cause the metal to expand or shrink, and thus damage the tooth surface or the adhesive that is sued to bind it to the tooth.
Nuts and hard candy
Nuts are off limits because they break into tiny, difficult to remove pieces that get lodged in the teeth and the device, and the gaps between them, and this can damage the teeth and the braces as well. Hard candy is off limits because it feeds bacteria and breaks into tiny pieces that are difficult to remove, and the eating of which creates suction that can remove the brackets.