Fructose and High Fructose Corn Syrup

Every time I write about diabetes, the topic of carbohydrates arises, and the subject eventually gets around to fructose.  Fructose, as you may know, is a form of sugar that occurs naturally in fruit and honey, and has a low glycemic index.  Based on these characteristics, it has often been assumed to be a good substitute for sucrose, or white sugar.

It's not.

Fructose is becoming more prevalent in the American diet these days, mostly in the form of high-fructose corn syrup (HFCS).  Undoubtedly, the major source of HFCS is soft drinks, but it's hard to find any sweetened food product that doesn't now contain HFCS.  If you want to lose weight or control your weight, you need to walk away from HFCS products (yet another reason walking is good for you).

The problem with fructose is in the way your body responds to it.  When you consume other carbohydrates, your pancreas releases insulin.  Insulin has several functions:

1. Once your digestive system has broken carbohydrates down into glucose and other components, insulin transports that glucose from the bloodstream into your muscle cells so it can be used as fuel.  Insulin also transports the glucose into your liver, so the energy can be stored for later use.
2. Insulin begins to suppress your appetite by triggering signals that you're satisfied and full.
3. Insulin stimulates production of the hormone leptin.  Leptin has been in the news lately as the latest fat fighter.  Leptin is produced by your fat cells, and not only does it limit fat storage, it also helps increase your metabolic rate to burn excess fat.

Fructose acts differently from other carbohydrates because it doesn't trigger the release of insulin.  As a result, fructose isn't moved to muscle cells for energy, leptin production isn't stimulated, and your metabolism doesn't increase.  Moreover, with fructose you never experience the accompanying reduction in appetite or feeling that you're full.

These facts have led many researchers to conclude that HFCS is the underlying cause of the unprecedented obesity problem we're experiencing today.