Q: I have a real sweet tooth and I used to eat a lot of sugar. In an effort to curb this habit and drop a few pounds, I've turned to artificial sweeteners, but I'm worried they could be just as bad for me. What can you tell me about them - am I making a mistake?

A: It's good that you're trying to control your sugar intake. Sugar comes in many forms, and all are major contributors to obesity and heart disease. In turn, overweight and obesity are tied to a whole host of other health problems.

Concentrated sweets, such as table sugar (sucrose) and high-fructose corn syrup, cause big jumps in blood glucose and insulin levels, which boost triglycerides, various inflammatory markers and oxygen-free radicals in the blood. In addition, long-term consumption of the large amounts of fructose found in many sugary products may damage the liver and cause insulin resistance.

At present, there are five FDA-approved artificial sweeteners: acesulfame, aspartame, neotame, saccharin and sucralose. Stevia is a plant-derived non-caloric sweetener that also has FDA approval. Though concerns about cancer have been largely dismissed, the chemicals in these artificial sweeteners may cause headaches and other reactions in some sensitive people.

Like you, most people consume artificial sweeteners because they want to lose weight. Replacing concentrated sugar with products that have very few, if any, calories should tilt energy balance in favor of weight loss. And some short-term studies suggest that artificial sweeteners may have that effect.

But other research raises concern that they may do just the opposite and actually promote weight gain. How so?

Artificial sweeteners are extremely sweet -- hundreds to thousands of times sweeter than table sugar. So people who habitually consume them may wind up desensitized to sweetness. Healthful, filling foods that are less sweet, such as fruits and vegetables, may become unappetizing by comparison. As a result, the overall quality of your diet may decline.

The calories you remove from your diet with a sweetener-for-sugar swap may also sneak back in, in other ways. You may end up replacing the missing sugar with other unhealthy simple carbohydrates and low-quality fats.

Some studies have even linked artificial sweetener consumption to obesity. But this connection should be interpreted cautiously, since it's likely that people consume artificial sweeteners because they've gained weight, not the other way around.

Your best bet may be to try to overcome your sweet tooth by gradually changing your flavor preferences. That way, perhaps you can reduce your desire for both sugar and artificial sweeteners.

Several studies have shown that people who manage to follow a low-sodium diet for several months wind up preferring lower concentrations of salt in their food. Yearning for sugar and fat can also be changed, although there's less experimental evidence for it.

And, believe it or not, you can increase your taste for foods that are certifiably healthful. By increasing your taste for and intake of vegetables, you may be able to edge out sugary and other unhealthy elements of your diet.

For example, if you don't like vegetables, it may be the bitter taste that is turning you off. But there are many different bitter-tasting compounds. Inborn variations in the two dozen or so bitter receptors in the tongue mean different people are more (or less) sensitive to the particular bitterness compounds in specific vegetables. You may respond more to the bitter compounds in, say, broccoli than those in kale. Experimenting with new, healthful foods may open your mind to foods that aren't at all sweet.

Don't count on artificial sweeteners for weight loss - they will never take the place of the tried-and-true method of taking in fewer calories and burning up more with daily exercise. It's true that artificial sweeteners are less harmful than added sugars, but most doctors recommend them only as a transitional aid to wean people off sugary beverages. With patient experimentation, you may come to prefer fresh fruit and other healthful foods that can't be matched by anything that comes from a factory. That would be sweet indeed!

Submit questions to harvard_adviser@hms.harvard.edu.