Is it true that humans don't need sugar? The surprising answer on glucose vs. added sugars

October 11, 2025 •

5 min read

The average American consumes about 17 teaspoons of added sugar daily, far exceeding health recommendations. This alarming statistic fuels a common debate: Is it true that humans don't need sugar at all, and is a sugar-free diet the ultimate goal for optimal health? The answer, however, is more nuanced than a simple yes or no.

Quick Summary

This article explores the body's actual requirement for glucose versus the widespread myth about needing all types of sugar. It clarifies the critical distinction between natural sugars found in whole foods and nutritionally empty added sugars, explaining how the body processes each and outlining the risks of excessive consumption. It also provides practical strategies for reducing added sugar intake.

Key Points

Humans need glucose, not added sugar: The body relies on glucose, a simple sugar, for energy, especially for the brain, but it can produce this from complex carbohydrates, proteins, and fats.
Differentiate natural vs. added sugars: Natural sugars in whole foods come with fiber and nutrients, while added sugars are nutritionally empty and contribute to health problems.
Excess added sugar is harmful: High intake of added sugar is strongly linked to weight gain, obesity, type 2 diabetes, heart disease, and chronic inflammation.
Read food labels carefully: Always check the 'Added Sugars' line and scan ingredient lists for common sugar names to identify hidden sources.
Prioritize whole foods: Get your carbohydrates and sweetness from fruits, vegetables, and whole grains for sustained energy and better health outcomes.
Strategize to reduce intake: Make gradual swaps like choosing water over sugary drinks, using spices for flavor, and baking with less sugar to effectively cut down on added sugars.

The Body's Essential Need for Glucose

While the popular health discourse often condemns "sugar" in its entirety, the truth is that a specific type of sugar, glucose, is the primary source of energy for nearly every living cell in the human body. The brain, in particular, is an energy-demanding organ that relies heavily on a consistent supply of glucose to function correctly. Without it, crucial brain functions like thinking, memory, and learning are impaired.

When we consume carbohydrates, our digestive system breaks them down into glucose, which is then absorbed into the bloodstream. A hormone called insulin helps transport this glucose into our cells for immediate energy. The liver and muscles also store excess glucose as glycogen, a readily available energy reserve for when blood sugar levels drop. If needed, the body can produce glucose from non-carbohydrate sources like fats and proteins through a process called gluconeogenesis. Therefore, while humans don't need to consume sugar directly from sweet sources, the body has a non-negotiable requirement for glucose, which it can obtain and produce from various food groups.

Added Sugars vs. Naturally Occurring Sugars

Central to this topic is the crucial distinction between different forms of sugar. All sugars are carbohydrates, but their source and form determine their nutritional impact. The two primary types are naturally occurring sugars and added sugars.

Naturally occurring sugars: These are intrinsic to whole foods such as fruits (fructose) and milk (lactose). When you eat an apple, for instance, the natural sugar it contains comes packaged with fiber, vitamins, minerals, and antioxidants. This combination means the body digests and absorbs the sugar more slowly, leading to a steady, sustained release of energy and preventing sharp blood sugar spikes.

Added sugars: These include sugars and syrups added to foods and beverages during processing or preparation, such as sucrose, high-fructose corn syrup, honey, and agave nectar. These are often found in processed foods, sugary drinks, desserts, and even unexpected items like condiments. Added sugars provide calories but offer virtually no nutritional benefit. Because they lack fiber and other nutrients, they are digested rapidly, causing a quick spike and subsequent crash in blood sugar and energy levels. Health experts, including the American Heart Association and the World Health Organization, specifically recommend limiting the intake of these added sugars.

Comparison Table: Natural vs. Added Sugars


Feature	Naturally Occurring Sugars	Added Sugars
Source	Whole fruits, vegetables, dairy products	Added during processing, preparation; syrups, honey, concentrates
Nutrient Content	Packaged with fiber, vitamins, minerals, antioxidants	Empty calories; contribute no nutritional value
Energy Release	Slow, sustained release due to fiber content	Rapid release, leading to quick spikes and crashes
Health Impact	Associated with improved health outcomes and reduced chronic disease risk	Strongly linked to obesity, heart disease, and type 2 diabetes

The Dangers of Excessive Added Sugar

While a moderate intake of natural sugar from whole foods is beneficial, excessive consumption of added sugars is a primary driver of numerous chronic health conditions. The problems stem from the rapid and high intake of calories without nutrients, which can overload the body's metabolic pathways.

Weight Gain and Obesity: Sugar-sweetened beverages, in particular, are a significant source of added sugar and contribute to weight gain. Liquid calories are less satiating than solid food, making it easy to consume an excess without feeling full. This overconsumption can lead to an accumulation of fat, particularly visceral fat around the abdominal organs, which increases the risk of metabolic diseases.
Type 2 Diabetes: The constant consumption of high levels of added sugar forces the pancreas to produce more insulin to manage blood sugar. Over time, this can lead to insulin resistance, a key risk factor for developing type 2 diabetes.
Heart Disease: Research has linked high added sugar intake to an increased risk of heart disease. Excess sugar can lead to higher blood pressure, chronic inflammation, and elevated triglyceride levels, all of which contribute to cardiovascular risk. The liver's processing of excess fructose from added sugars into fat can also contribute to fatty liver disease, which is linked to heart disease.
Dental Health: The bacteria in our mouths feed on sugar and produce acid, which breaks down tooth enamel and leads to cavities and tooth decay.

Practical Steps to Reduce Added Sugar Intake

Cutting down on added sugar is one of the most effective dietary changes you can make for better health. Here are some strategies:

Read Nutrition Labels: Pay attention to the "Added Sugars" line on the nutrition facts panel. Also, scan the ingredients list for other names of sugar, such as corn syrup, molasses, and any ingredient ending in "-ose" (like sucrose or fructose). Aim for products with lower added sugar content.
Swap Sugary Beverages: Replace soda, sweetened fruit juices, and sports drinks with water, unsweetened iced tea, or sparkling water with a squeeze of lemon.
Choose Whole Foods: Get your sweet fix from whole fruits, which contain natural sugars along with beneficial fiber. This provides a more balanced and nutritious energy source.
Cook from Scratch: Prepare your own meals and baked goods to control the amount of sugar added. You can often reduce the sugar called for in recipes by a third or half without affecting the taste.
Use Spices Instead of Sugar: Enhance flavors with spices like cinnamon, nutmeg, or ginger, which can provide a sweet-like aroma without the added sugar.
Be Mindful of Hidden Sugars: Sugars are hidden in many processed foods. Be wary of:
- Low-fat or fat-free products, which often compensate for flavor by adding sugar.
- Condiments like ketchup, barbecue sauce, and salad dressings.
- Flavored yogurts, which can contain a surprising amount of added sugar.
- Granola bars and breakfast cereals marketed as healthy.

Conclusion

So, is it true that humans don't need sugar? The definitive answer is that the human body does not require added sugars for fuel and can function optimally without them. The necessary glucose can be derived from nutrient-dense whole foods like vegetables, whole grains, fruits, and dairy. By distinguishing between naturally occurring sugars and added sugars, and making conscious choices to limit the latter, individuals can significantly improve their overall health, manage their weight, and reduce the risk of chronic diseases. For better health, the focus should not be on eliminating all sugar, but rather on minimizing added sugar while prioritizing whole, unprocessed foods. For further reading, visit the World Health Organization's fact sheet on healthy diet.

Frequently Asked Questions

Completely eliminating all sugars, including natural sugars in fruits and milk, is not a healthy choice, as glucose is essential for bodily functions. The focus should be on minimizing or eliminating added sugars while maintaining a balanced intake of whole foods.

Your body can break down complex carbohydrates found in whole grains, fruits, and vegetables into glucose for energy. It can also produce glucose from fats and proteins through a process called gluconeogenesis, ensuring a consistent fuel supply even without consuming added sugar.

Yes, natural sugars found in whole fruits and vegetables are considered healthier because they are digested more slowly and come packaged with essential fiber, vitamins, and minerals. Added sugars, in contrast, provide empty calories and are rapidly absorbed.

Health organizations like the World Health Organization (WHO) recommend limiting free sugars to less than 10% of total energy intake, with a further reduction to below 5% suggested for additional health benefits. For many adults, this translates to about 6-9 teaspoons per day.

Yes, reducing the intake of added sugars can aid in weight management. Excessive sugar consumption, particularly from beverages, is a major contributor to consuming excess calories, which can lead to weight gain and obesity.

Added sugars can be found in many processed and packaged foods, including condiments like ketchup and salad dressings, flavored yogurts, granola bars, breakfast cereals, and canned fruit in syrup. Always check the nutrition facts panel and ingredients list to identify them.

The FDA requires that the Nutrition Facts label list 'Added Sugars' separately, under 'Total Sugars'. You can also look at the ingredient list; natural sugars are not typically listed as an ingredient, while added sugars are identified by names like high-fructose corn syrup, sucrose, or honey.