Questions and Answers About Sugars

Q&A: Questions and Answers About Sugars

Think about the foods and drinks you most enjoy—do they have anything in common? Chances are, many of them contain some form and quantity of sugar. It could be naturally occurring sugars, like in fresh fruits and vegetables, or it could be the added sugars that are typically found in desserts.

We are born liking sweet taste, and most people continue to enjoy the sweet taste of sugars throughout their life. Unfortunately, most Americans consume more added sugar than is recommended by health and nutrition experts. But that doesn’t mean that sugars need to be eliminated from a balanced plan for healthy eating. This article addresses common questions that many people have about sugars and their role in a healthful diet.

What are sugars?

Sugars are carbohydrates, one of the three macronutrients—along with dietary fat and protein—that provide us with calories. But all carbohydrates are not sugars.

Sugars occur naturally in dairy, fruits, and vegetables. Sugars are also used as ingredients in many packaged foods and beverages. The most familiar sugar is sucrose (i.e., table sugar), which is a disaccharide made of two simple sugars: the monosaccharides fructose and glucose. Sucrose, fructose, and glucose are examples of sugars that are naturally occurring but are also used as added sugars. Other sugars commonly added to foods include corn syrup and high-fructose corn syrup.

Why are sugars added to foods?

Sugars play important roles in foods, and taste is only one of them. In addition to sweet taste, sugars provide various technical functions in food science, including contributing to a food’s color, structure, and texture; balancing acidity; controlling crystallization in candies and chocolates; providing a medium for the growth of yeast in baked goods; and preventing spoilage by binding water to reduce its activity.

Are sugars safe to eat?

The U.S. Food and Drug Administration (FDA) has examined numerous sugars, including allulose, glucose, dextrose, fructose, sucrose, high fructose corn syrup, lactose and maltose, and determined that they are “generally recognized as safe” (GRAS). You can learn more about the FDA GRAS review process here.

How does the body use sugars?

Sugars are one source of energy for the body, with each gram of sugar providing about four calories. The body uses all types of sugars in similar ways. Once ingested, sugars are broken down into their simplest form. During this process, the body does not distinguish between sugars that are added to foods and sugars that occur naturally in foods, because these sugars are, chemically, the same.

In the digestion of the disaccharide sucrose—the most common type of sugar—the monosaccharides glucose and fructose are released into the bloodstream. Glucose is the primary fuel utilized by the brain and working muscles. To protect the brain from a potential fuel shortage, the body maintains a constant level of glucose in the blood. Dietary glucose can be stored in the liver and muscle cells in units called glycogen. When the level of glucose in the blood starts to drop, glycogen can be converted to glucose to maintain blood glucose levels. Several hormones, including insulin, work rapidly to regulate the flow of glucose to and from the blood to keep it at a steady level. Insulin also allows the muscles to get the glucose they need from the blood supply. Fructose is metabolized by the liver, where it is converted into energy sources for the body through a process that does not require insulin.

Do sugars fit into a healthful eating pattern?

A healthful eating pattern includes all five food groups: Dairy, fruits, grains, protein foods like meats and legumes, and vegetables. Some foods in these groups naturally contain sugars, such as fruits, vegetables and cow’s milk, which are sources of important nutrients like calcium, dietary fiber and potassium that many Americans don’t get enough of. Other foods in a healthful eating pattern may contain added sugars; examples include breads, alternative dairy beverages, and fruit canned in syrup.

In sum, a healthy eating pattern can include both naturally occurring and added sugars. While there is no formal recommendation for how much naturally occurring sugar to consume, there is a recommendation for added sugars. The most recent Dietary Guidelines for Americans recommend limiting our intake of added sugars to less than 10% of our total calories consumed per day. This amounts to less than 200 calories, or 50 grams, of added sugars in a 2,000-calorie daily diet.

What does “sugar free” and “reduced sugar” mean on the labels of food packages?

The FDA regulates sugar content claims on food packaging. For example, for a food to use terms such as “sugar free,” “no sugar,” or “zero sugar” on its packaging, it must contain less than 0.5 grams of total sugars per serving. Terms such as “reduced sugar,” “less sugar,” or “lower in sugar” mean that food must contain at least 25% less sugar per serving than the regular product.

Sugars may not be added to a food that uses the terms “no added sugar,” “without added sugar,” or “no sugar added” on its packaging. Processing also must not increase the amount of sugars in the food.

Do sugars cause diabetes?

Diabetes is a complicated, chronic disease that affects the way the body regulates blood glucose levels. People with diabetes either do not make enough insulin in their bodies or cannot use the insulin their bodies do make. Insulin is needed for the body to keep glucose levels in the body’s blood supply steady and to allow the muscles to get the glucose they need from the blood.

Diabetes presents itself in various forms, including type 1, type 2 and gestational diabetes. About 90% of people with diabetes have type 2 diabetes. People with type 2 diabetes can make insulin, but their body does not use it effectively, which leads to higher-than-normal blood glucose levels.

Experts do not know the exact cause of diabetes, but they do know that it is not caused by consuming sugars. Many factors contribute to developing type 2 diabetes, some of which you can attempt to modify—like your weight status and level of physical activity—and others that you cannot change—like your age and genes.

Do sugars cause weight gain?

No one source of calories causes weight gain. The predominant view among nutrition scientists is that weight gain occurs when we regularly consume more calories than we use. Excess calories may come from sugars, or any food, beverage, or nutrient that provides calories.

Do sugars cause tooth decay?

Tooth decay is the result of many factors, including heredity causes and the make-up and flow of a person’s saliva. Sugars and other carbohydrates, such as starchy foods, also play a part. Bacteria on the teeth (also known as dental plaque) feed on carbohydrates and make acids that weaken tooth enamel and contribute to cavity formation.

In addition to what we eat, the frequency of our eating also matters when it comes to dental health. Frequently eating snacks that contain sugar and carbohydrates, especially those that stick to the teeth, may increase your chances of tooth decay. Proper oral hygiene that includes brushing your teeth twice a day with fluoride toothpaste can help reduce your risk of tooth decay.

What types of sugars are in foods?

A variety of sugars are found in the (whole and packaged) foods and beverages that we consume. Here are a few that you may have come across:

  • Allulose: A type of rare sugar that is found naturally in small quantities in brown sugar and maple syrup, as well as in dried fruits such as figs and raisins. Allulose contains 90% fewer calories than sucrose. It may also be commercially produced from fructose or corn.
  • Corn syrup: Commercially produced from corn and usually 100% glucose, corn syrup is different from high fructose corn syrup (HFCS).
  • Fructose: Sometimes called “fruit sugar,” fructose is found primarily in fruits, but also naturally occurs in vegetables, honey, sugar beets and sugar cane. In nature, fructose does not occur in isolation, it is always found with another sugar. Fructose is also commercially produced from corn starch for use as a caloric sweetener that is added to foods and beverages in the form of crystalline fructose. Fructose makes up half the sugars in sucrose and slightly more than half the sugars in HFCS. Fructose is about 1 ½ time sweeter than sucrose. Fructose does not raise blood glucose levels like other sugars because it is metabolized in the liver through a process that does not require insulin.
  • Galactose: A monosaccharide found naturally in milk and dairy foods, galactose combines with glucose to form the disaccharide lactose.
  • Glucose: The main source of energy for the body, glucose may be consumed as a monosaccharide or can result from carbohydrate and sugars metabolism. Glucose is sometimes referred to as dextrose. Starch is composed of long chains of glucose. Glucose makes up exactly half the sugars in sucrose and nearly half the sugars in HFCS. Glucose is slightly less sweet than sucrose.
  • High-fructose corn syrup (HFCS): A mixture of glucose and fructose monosaccharides that is commercially produced from corn. The most common form of HFCS consists of 55% fructose and 45% glucose, which has the same sweetness as sucrose.
  • Lactose: The sugar found naturally in milk, lactose is a disaccharide composed of one galactose molecule and one glucose molecule. Lactose is sometimes called “milk sugar.”
  • Maltose: A disaccharide composed of two glucose molecules, maltose is found in molasses and is used in fermentation.
  • Sucrose: A disaccharide composed of glucose and fructose, sucrose is also known as table sugar. Sucrose is found naturally in plants such as fruits, vegetables and nuts. Sucrose is also commercially produced from sugar cane and sugar beets.