Carbohydrates often get a bad rap, especially when it comes to weight gain. But carbohydrates, often called carbs, aren't all bad. Because of their many health benefits, carbs have a rightful place in the diet. In fact, the body needs carbs to work well.

But some carbs can be better for you than others. Understand more about carbohydrates and how to make healthy diet choices.

Carbohydrates are a type of macronutrient found in many foods and beverages. Most carbs occur naturally in plant-based foods, such as grains. Food manufacturers also add carbs to processed foods in the form of starch or added sugar.

Common sources of naturally occurring carbohydrates include:

• Fruits
• Vegetables
• Milk
• Nuts
• Grains
• Seeds
• Beans, peas and lentils

There are three main types of carbohydrates:

• Sugar. Sugar is the simplest form of carbohydrate. It occurs naturally in some foods, including fruits, vegetables, milk and milk products. Types of sugar include fruit sugar (fructose), table sugar (sucrose) and milk sugar (lactose). Added sugars can be found in many foods, such as cookies, sugary drinks and candy.
• Starch. Starch is a complex carbohydrate. This means it is made of many sugar units bonded together. Starch occurs naturally in vegetables, grains, and cooked dry beans and peas.
• Fiber. Fiber also is a complex carbohydrate. It occurs naturally in fruits, vegetables, whole grains, and cooked dry beans and peas.

The terms "low carb" or "net carbs" often appear on product labels. But the Food and Drug Administration doesn't use these terms, so there's no standard meaning. Typically, the term "net carbs" is used to mean the amount of carbs in a product excluding fiber or excluding both fiber and sugar alcohols.

You probably have also heard talk about the glycemic index. The glycemic index classifies carbohydrate-containing foods according to their potential to raise blood sugar levels.

Weight-loss diets based on the glycemic index typically suggest limiting foods that are higher on the glycemic index. Foods with a relatively high glycemic index ranking include potatoes, white bread, and snack foods and desserts that have refined flours.

Many healthy foods are naturally lower on the glycemic index. Examples include whole grains, legumes, vegetables, fruits and low-fat dairy products.

The Dietary Guidelines for Americans recommend that carbohydrates make up 45% to 65% of total daily calories.

So if you get 2,000 calories a day, between 900 and 1,300 calories should be from carbohydrates. That translates to between 225 and 325 grams of carbs a day.

You can find the carbohydrate content of packaged foods on the Nutrition Facts label. The label shows total carbohydrates — which can include fiber, total sugars and added sugars.

Despite their bad reputation, carbohydrates are vital to your health for many reasons.

Providing energy

Carbohydrates are the body's main fuel source. During digestion, sugars and starches are broken down into simple sugars. They're then absorbed into the bloodstream, where they're known as blood sugar (blood glucose).

From there, glucose enters the body's cells with the help of insulin. Glucose is used by the body for energy. Glucose fuels your activities — whether it's going for a jog or simply breathing and thinking. Extra glucose is stored in the liver, muscles and other cells for later use. Or extra glucose is converted to fat.

Protecting against disease

Some evidence suggests that whole grains and dietary fiber from whole foods help lower your risk of heart disease and stroke. Fiber may also protect against obesity, colon and rectal cancers, and type 2 diabetes. Fiber is also essential for optimal digestive health.

Controlling weight

Evidence shows that eating plenty of fruit, vegetables and whole grains can help you control your weight. Their bulk and fiber content aids weight control by helping you feel full on fewer calories. Despite what proponents of low-carb diets claim, few studies show that a diet rich in healthy carbs leads to weight gain or obesity.

Carbohydrates are an essential part of a healthy diet, and they provide many important nutrients. Still, not all carbs are equally good for you.

Here's how to make healthy carbohydrates work in a balanced diet:

• Focus on eating fiber-rich fruits and vegetables. Aim for whole fresh, frozen and canned fruits and vegetables without added sugar. Or have measured portions of fruit juices and dried fruits, which are concentrated sources of natural sugar, but have more calories. Whole fruits and vegetables have many health benefits. They add fiber, water and bulk, which help you feel fuller on fewer calories.
• Choose whole grains. Whole grains are better sources than refined grains of fiber and other important nutrients, such as B vitamins. Refined grains go through a process that strips out parts of the grain — along with some of the nutrients and fiber.
• Stick to low-fat dairy products. Milk, cheese, yogurt and other dairy products are good sources of calcium, protein, vitamin D, potassium, and other vitamins and minerals. Consider the low-fat versions to help limit calories and saturated fat. And watch out for dairy products that have added sugar.
• Eat more beans, peas and lentils. Beans, peas and lentils are among the most versatile and nutritious foods. They are typically low in fat and high in folate, potassium, iron and magnesium. And they have useful fats and fiber. They are a good source of protein and can be a healthy substitute for meat, which has more saturated fat and cholesterol.
• Limit added sugars. Added sugar probably isn't harmful in small amounts. But there's no health benefit to having any amount of added sugar, such as in cookies and pastries. The Dietary Guidelines for Americans recommend that less than 10% of calories you eat or drink every day come from added sugar. Eating or drinking too many foods with sugar can also cause you to take in more than the calories you need each day.

So choose your carbohydrates wisely. Limit foods with added sugars and refined grains, such as sugary drinks, desserts and candy. These are high in calories but low in nutrition. Instead, select fruits, vegetables and whole grains.