From a young age we have been told that too much sugar was bad for us. Overloading on sugary sweets will not only cause the obvious weight gain, it can also make you more vulnerable to Type 2 Diabetes, as well as other serious health problems.
Recent research has also shown a large part of aging is due from elevated blood sugar, or Glycation, a destructive process that damages cell tissue, causing not only physical signs of aging such as wrinkles and hyperpigmation, but also age related diseases including arterial stiffening, cataracts, and has even been linked to certain neurological disorders such as Alzheimer's and strokes.
It seems obvious that the best way to avoid Glycation would be to cut back on the sugary stuff. However, food manufacturers do not make this so simple. Watch out for words such as "high fructose corn syrup" or the new simple word for it, "fructose", "sucrose", and "glucose". It's always best to try to avoid processed foods all together, and sticking to whole foods (cook, don't be lazy!) I'm not saying that eating a cookie or a piece of cake once in a while is going to make you look like the old lady from Titanic, just try to not to overdo it, and when you do, go for the homeade stuff over prepackaged. Sugar may not be good for you, but processed sugar is by far worse.