What is the difference between:

  • Glucose?
  • Fructose?
  • Sucrose?

I know they are all forms of sugar, and your body needs them.

But what is what?

OK, I do know that "Fructose is a natural sugar found in a variety of foods such as fruit, honey and vegetables."

What is normal sugar then, like the stuff you buy from the shops to put in your coffee?


  • Nutrition topics unrelated to physical fitness or exercise is considered off-topic according to our faq.
    – Matt Chan
    Aug 30 '12 at 2:30

Glucose and Fructose are monosaccharides, the simplest forms of sugars that your body can use directly. Sucrose and high fructose corn syrup are disaccharides, or a larger more complex compound of glucose and fructose. Sucrose, the type of table sugar from sugar cane or beet sugar, is 50% fructose and 50% glucose. High fructose corn syrup is a manufactured sugar that is engineered to certain ratios:

  • HFCS 55: 55% fructose to 45% glucose
  • HFCS 42: 42% fructose to 53% glucose
  • HFCS 90: 90% fructose to 10% glucose--usually used to blend with HFCS 42 to make HFCS 55

The health concerns usually revolve around the level of fructose more than glucose. For example fructose malabsorption is fairly common. Most commonly, the biggest concern is a link between fructose and visceral fat levels. Visceral fat is the fat below the muscle surface packed between your organs. Too much visceral fat will cascade into several health disorders. This is primarily a concern because we have radically increased our fructose intake from 1970 to 2000.

As with all things dietary, too much of any one thing is not healthy. Your diet should be very balanced.

  • On the other side of things, glucose is what controls the glycemic index, which more directly controls insulin response, which in turn can make you hungry and relates to insulin sensitively.
    – michael
    Aug 29 '12 at 14:35

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