The evidence is clear that upon the introduction of high fructose corn syrup, society has gotten fatter and fatter.  Studies now show the direct mechanism of high fructose corn syrup (HFCS) in causing obesity and diabetes, particularly in children.

Researchers have found new evidence that soft drinks sweetened with high-fructose corn syrup (HFCS) may contribute to the development of diabetes, particularly in children. In a laboratory study of commonly consumed carbonated beverages, the scientists found that drinks containing the syrup had high levels of reactive compounds that have been shown by others to have the potential to trigger cell and tissue damage that could cause the disease, which is at epidemic levels.

Not only does this engineered food lead to cellular damage, but it packs on the pounds as it triggers the body's metabolic-regulating hormones to store more calories as fat and keep you feeling hungry.  

A good article by John Mercle M.D. gives a broad overview of some of the detrimental effects of HFCS:

Increased LDL's (the bad lipoprotein) leading to increased risk of heart disease.

Altered Magnesium balance leading to increased osteoporosis.

Increased risk of Adult Onset Diabetes Mellitus.

Fructose has no enzymes or vitamins thus robbing the body of precious micro-nutrients.

Fructose interacts with birth control pills and can elevate insulin levels in women on the pill.

Accelerated aging.

Fructose inhibits copper metabolism leading to a deficiency of copper, which can cause increased bone fragility, anemia, ischemic heart disease and defective connective tissue formation among others.

Clearly, your best bet is to steer clear of HFCS.  Become a food detective, turn your labels upside down and don't purchase anything containing it, and certainly don't feed it to your kids.  A child's growing body is highly sensitive and damage done at a ripe young age may last a lifetime.