BY MARY-JO SAWYER Special correspondent

Sugar substitutes can reduce overall calorie intake and may help you lose weight. However, cutting back on sugar in one area, like drinking diet sodas, only to splurge on dessert or large portions of healthful foods can cause weight gain.

When I attended the Academy of Nutrition and Dietetics’ Food & Nutrition Conference & Expo in Boston last month, I tasted a variety of sweeteners. No matter your personal feelings about sugar substitutes, many people enjoy them daily.

Some people don’t know much about their sweetener other than the color of its box. Bottom line: Read the label to know what’s in it. There are two types of sweeteners: nutritive and nonnutritive.

Nonnutritive sweeteners are very low in calories or calorie-free. Examples are Splenda (sucralose) in the yellow box, Equal and NutraSweet (aspartame) in blue, Sweet’N Low (saccharin) in pink and Truvia (stevia) in green.

One new product, Splenda Naturals, contained stevia instead of sucralose. However, it was made from a different extract of the stevia plant’s leaf to decrease the bitter aftertaste sometimes associated with original stevia.

We’ll see more products like that as companies combine several sweeteners in new foods and beverages. One calorie-free soda I tasted contained stevia, monk fruit and erythritol. One sip, and my taste buds were shocked by the excessive sweetness.

Monk fruit is a calorie-free sweetener that comes from a sweet melon in China.

Erythritol is a sugar alcohol from plants. Sugar alcohols are digested differently than table sugar (sucrose) and don’t affect blood sugars, which is helpful for those with diabetes. Other sugar alcohols, such as xylitol and sorbitol, might have a laxative effect if overused, but this is less of a problem with erythritol.

Some baking blends made with nonnutritive sweeteners contain sugar. Sugar adds moistness and volume to baked goods, plus allows them to brown. These blends have about 50 percent fewer calories: 400 calories per cup rather than 775 for sugar.

Nutritive sweeteners are those that contain calories. These natural sweeteners are different forms of sugar and contain the same or more calories than sugar.

Honey has 64 calories per tablespoon or 1,041 calories per cup. Agave nectar is the sap extracted from the Mexican plant that also is used to make tequila. Agave nectar has 60 calories per tablespoon or 960 per cup.

Sugar in the raw, made from tropical sugar cane, isn’t quite as processed as white sugar. Don’t be fooled by the brown color — it has the same number of calories as white sugar: 48 calories per tablespoon.

Any sweeteners can be part of a healthful diet, but don’t overuse them. Too much can keep your taste buds primed for high levels of sweetness, and you might miss out on the natural sweetness of simple fresh fruit.