The trouble is, foods and beverages with added sugars are plentiful today and usually cheaper on a per-calorie basis than vegetables or naturally sweet fruits. Between 1970 and 2005, consumption of added sugars in the typical American diet increased by 19% to a total of 64 kilograms per year. Last week, the American Heart Assn. issued a statement calling on Americans to cut back on added sugars of all types.
Foods are sweetened with various sugars: sucrose, fructose, honey, corn syrup and more. Is there much to choose between them? Passions burn fiercely here. Some people are convinced that high fructose corn syrup has properties that link it to the fattening of America -- partly for that reason, today regular sugar is almost achieving health-food status in some circles. Others swear by less-purified brown sugars or honey.
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And many people don't know what all this sweet stuff even is.
Here's a primer on common sweeteners, as well as some not-so-common ones.
Table sugar, or sucrose, is the familiar stuff we use in cubes or by the spoonful. We sweeten our coffee with it, bake with it and know its flavor so well that it is the yardstick to which we compare other sweet flavors.
"When you say sweet, you have the image in your mind of sucrose," says Sidney Simon, a professor of neurobiology at Duke University who studies taste.
Most commercial sucrose comes from sugar beets and sugar cane. The natural sugar content of the plants is refined to varying degrees to produce granulated, powdered, brown and specialty sugars, such as demerara and muscovado. Molasses, a byproduct of the refining process, flavors and moistens the darker sugars. Crystals in these sugars range in size and flavor, but the sweetness in each is provided by sucrose.
Chemically, sucrose is a disaccharide, meaning that it is composed of two simple sugars linked together. In the case of sucrose, the two are fructose and glucose. During digestion, the bond between the two is cut and they are absorbed separately by the small intestine.
Sucrose from any source -- brown or white, beet or cane -- contains 4 calories per gram, as do other sugars. In other words, equal amounts of different sugars provide the same amount of energy to the body. However, some sugars taste sweeter than others, so you don't need to add as much to get the same level of sweetness.
When glucose is added to foods, it appears on nutrition labels as glucose, corn sugar or dextrose.
And even if it isn't added to foods, we end up with a lot of it. Many carbohydrates and sugars are ultimately converted by our bodies into glucose. Simple sugars such as fructose and galactose can be converted to glucose by the liver. More complex carbohydrates are digested down to glucose in the gut before being absorbed into the bloodstream.
These include the disaccharide maltose, which is made up of two linked molecules of glucose; maltodextrins or dextrins, which are chains of maltose molecules, and starches, which are chains of maltodextrins.
Once digested, glucose supplies the energy most parts of the body need to work. The amount of glucose in the bloodstream -- the blood sugar level -- is known to affect athletic performance, brain function, appetite and emotions.
Because this sugar is so critical, levels of available glucose are tightly regulated by hormones such as insulin; errors in this system can lead to disorders such as diabetes. Diabetics inject insulin to keep their blood sugar from going too high and, when necessary, take easily absorbed glucose tablets to quickly bring it back up to healthy levels.
Fructose is often called fruit sugar, which is a bit of a misnomer. Although fruit and fruit juice contain fructose, they also contain glucose and sucrose. And these days, the main source of dietary fructose is added sweeteners, not fruit.