What Happens to Your Body When You Eat Too Much Sugar

Following a healthy, well-rounded diet is one of the best ways to care for your health and reduce your risk of developing a variety of chronic diseases, from type 2 diabetes to heart disease.

Though your eating pattern as a whole is what matters most when it comes to overall health, certain dietary components, such as foods and drinks high in added sugar, could harm your body and increase disease risk if you eat too much of it.

Eating too much added sugar can negatively impact your blood sugar control, heart health, body weight, and more.

Here’s what happens to your body when you eat too much sugar.

Risks of Eating Too Much Sugar

Added sugar refers to sweeteners that are added to food and beverages to enhance flavor, such as the sugar added to baked goods, ice cream, candy, flavored yogurt, and soda. It’s different from the natural sugars found in fruits, dairy products, and vegetables.

Some of the most commonly consumed added sugars include cane sugar, high-fructose corn syrup, and honey. According to the 2020-2025 Dietary Guidelines for Americans, added sugars contribute nearly 270 calories to the average American's daily calorie intake.

The top sources of added sugar in America are sugar-sweetened beverages, desserts, snack foods, and sweetened coffee beverages.

Though added sugar is safe in small amounts, consuming too much added sugar can lead to a number of health issues. 

Could Increase Your Risk for Heart Disease

Heart disease, including coronary artery disease—the most common type of heart disease in the U.S.—is the leading cause of death worldwide. Though a number of factors can impact a person’s risk of heart disease, a diet high in added sugar can contribute to developing heart disease.

Research shows that diets high in added sugar increase heart disease risk factors such as high triglycerides, elevated blood sugar and blood pressure, obesity, and atherosclerosis—the narrowing of arteries caused by fatty deposits accumulating along artery walls.

A 2022 review that included data on over 100,000 women found that those who consumed 15% or more of their total daily energy intake as added sugar were 20% more likely to develop coronary heart disease compared to women who consumed less sugar. The study also found that consuming one or more servings of sugar-sweetened beverages per day was associated with a modestly increased risk of total heart disease, coronary heart disease, and total risk of stroke.

May Cause Fatty Liver

Consuming too much added sugar, especially in the form of fructose, can damage the liver and cause fat to build up in this critical organ.

Fructose is a type of sugar that's almost exclusively broken down by the liver, where it’s converted into energy to be used by the body or stored as glycogen for later use. However, when too much fructose is consumed from sugary foods and drinks like soda, it overwhelms the liver and causes excess glycogen to be turned into fat. This leads to a buildup of excess fat in the liver, which is known as Non-Alcoholic Fatty Liver Disease (NAFLD).

A 2015 study that included data on 5,908 adults found that people who consumed sugar-sweetened beverages daily had a 56% greater risk of developing fatty liver disease compared to non-consumers.

Increases Diabetes Risk

Sugary foods and drinks can contribute to diabetes development in several ways. Consuming too much added sugar can lead to a calorie surplus. Consuming too many calories leads to weight gain over time, which can eventually lead to obesity—a key risk factor for type 2 diabetes. 

Additionally, consuming large amounts of added sugar can lead to elevated blood sugar and resistance to insulin, a hormone that shuttles blood sugar into cells where it can be used for energy. Insulin resistance is when cells stop responding appropriately to insulin, which causes high blood sugar and insulin levels.

A 2021 review of 16 studies found that each serving per day increment of sugar-sweetened beverage intake increased the risk of developing type 2 diabetes by 27%.

Some evidence suggests that when added sugar is restricted to less than 5% of total calories, it may reduce the risk of developing type 2 diabetes by 50%.

Harms Dental Health

A high-sugar diet is one of the top causes of dental caries in adults and children. When you eat sugary foods or drink sugar-sweetened beverages, bacteria in your mouth break down the sugar, which releases acidic byproducts that damage the teeth by demineralizing tooth enamel.

What’s more, sugary beverages like soda are naturally acidic, which also erodes tooth enamel.

Studies show that high-sugar diets are a risk factor for a variety of dental issues, from cavities to gum disease, and that added sugar intake is strongly linked to cavities in both adults and children.

Could Contribute to Weight Gain and Belly Fat

Eating too much added sugar can cause you to take in excess calories, which leads to weight gain over time. Because sugary foods and drinks are usually low in satiating nutrients such as fiber and protein, they’re easy to overeat. Plus, certain sweeteners, like fructose, may increase feelings of hunger, which further drives calorie intake.

People who follow diets high in added sugar are more likely to develop obesity over time than people who consume low amounts of added sugar. What’s more, added sugar intake is associated with an accumulation of a harmful type of fat called visceral fat. Visceral fat is a type of deep belly fat that surrounds your internal organs. Having high amounts of visceral fat is strongly associated with an increased risk of a number of health conditions, including type 2 diabetes and heart disease.

A 2020 study that included 3,070 people who were followed for 25 years found that the participants who consumed greater amounts of added sugar had higher levels of visceral fat as well as general body fat compared to people who consumed less added sugar.

May Harm Brain Health

High-sugar diets have been linked to impaired memory, cognitive decline, and a greater risk of mental health conditions like depression. Studies show that diets high in added sugar can reduce brain volume, which is associated with cognitive decline.

A 2017 study that included 4,276 people over the age of thirty found that those who consumed more than one sugary drink per day had lower total brain volume and poorer memory compared to people who consumed less than one sugary drink per day.

High-sugar diets have also been associated with the development of mental health conditions such as anxiety and depression. A 2017 study that included data on 23,245 people found that men who consumed the most added sugar had a 23% increased risk of developing common mental disorders (CMD), which includes depressive and anxiety disorders, after 5 years.

How Much Sugar Should You Eat in a Day?

In order to stay healthy and reduce your risk of health issues linked to high added sugar intake, it’s recommended to limit your intake of sugary foods and beverages.

Even though health organizations recommend low-sugar diets for optimal health, added sugars make up a large part of most Americans’ diets. The average American consumes 17 teaspoons of added sugar per day, which equates to around 270 calories. Added sugar accounts for up to 17% of U.S. adults’ total energy intake and up to 14% of the total energy intake of U.S. children.

To help reduce the negative health impacts of added sugar, U.S. health organizations recommend limiting foods and drinks that contain added sugar and keeping added sugar under a certain percentage of total calorie intake. The 2020-2025 Dietary Guidelines for Americans suggest that children and adults aged two and over limit their calories from added sugar to less than 10% per day, while The American Heart Association recommends limiting added sugars to no more than 6% of calories per day, which equates to six and nine teaspoons of added sugar per day for women and men, respectively.

It’s important to note that added sugar consumption should be completely avoided in children under the age of two.

Even though these recommendations are helpful, most health experts agree that limiting added sugar as much as possible is best for maintaining optimal health and reducing disease risk. To cut back on added sugar, try reducing your intake of sugar-sweetened beverages like soda and sugary coffee drinks and cutting back on candy, baked goods, and other sugar-laden foods. 

When To See Your Healthcare Provider

If you’re concerned about your sugar intake, your healthcare provider can go over your dietary intake and recommend simple changes to help you cut back on added sugar. 

They can also rule out underlying medical conditions that could be caused by high sugar intake, such as high blood sugar levels and fatty liver.

Working with a healthcare provider who specializes in nutrition, such as a registered dietitian, could be helpful for those who find it difficult to reduce their added sugar intake. In addition to cutting back on sugary drinks and foods, a dietitian can recommend other simple dietary changes that can help you eat less sugar, such as adding in filling foods that are high in fiber and protein, cooking more meals at home, and swapping sugary drinks for non-caloric or low-sugar beverages. 

A Quick Review

Eating too much added sugar can negatively impact your blood sugar control, heart health, body weight, and more.

Too much sugar in your diet can lead to an increased risk of heart disease, fatty liver disease, increased risk of diabetes, and reduced dental health.

To help reduce the negative health impacts of added sugar, U.S. health organizations recommend limiting foods and drinks that contain added sugar and keeping added sugar under a certain percentage of total calorie intake.

Talk to your healthcare provider if you suspect you may be eating too much sugar. They can go over your dietary intake and recommend simple changes to help you cut back on added sugar.