Can Eating Too Much Sugar Cause Diabetes? Here's What Experts Say

What Is Diabetes?

Diabetes is an umbrella term used to describe dysfunction in glucose metabolism, which causes hyperglycemia (high blood sugar). This can occur when the body makes little or no insulin, the body’s cells are resistant to the insulin it makes, or a combination of both. There are various types of diabetes, with different risk factors and causes. The American Diabetes Association Standards of Care breaks down the main types of diabetes:

Type 1 Diabetes: An autoimmune disease in which the body mistakenly attacks itself, resulting in insulin insufficiency or complete lack of insulin production. People with type 1 diabetes must take insulin to live.

Prediabetes: A precursor to type 2 diabetes, in which blood sugars are high but not high enough to diagnose diabetes. Insulin resistance is present in prediabetes, and lifestyle factors, such as diet, exercise and weight loss, can reverse, delay or prevent a type 2 diabetes diagnosis.

Type 2 Diabetes: A non-autoimmune diabetes that's more commonly diagnosed later in life but can occur in children. This type of diabetes is highly associated with lifestyle, meaning that your eating and activity habits increase your risk. People with type 2 diabetes often have metabolic syndrome—a cluster of health conditions that increase your risk of coronary heart disease, diabetes, stroke and other chronic diseases. To be diagnosed with metabolic syndrome, you must have three or more of these conditions: a large waistline, high blood pressure, high cholesterol, high triglycerides, high blood sugar and low HDL cholesterol, per the National Heart, Lung and Blood Institute.

Gestational Diabetes: Diagnosed in the second or third trimester of pregnancy, gestational diabetes causes high blood sugar due to hormonal changes during pregnancy. However, it usually usually resolves once the baby is born.

How Your Body Metabolizes Sugar

“Your body needs insulin to metabolize sugar. Insulin helps transport the glucose into the cells of the body,” says Tina Cheng, D.O., a pediatric endocrinologist from Good Samaritan University Hospital in New York. When you eat foods containing carbohydrates, like dairy products, grains, beans, fruit, vegetables and sugary foods, the body breaks them down into glucose (aka sugar). The pancreas then produces insulin to move sugar from the bloodstream into the cells to use for energy.

Foods considered simple sugars, like cane sugar, fruit juice, honey and syrup, are metabolized more quickly than more complex carbohydrate sources, such as whole grains and legumes. These foods can cause a surge of insulin to be excreted.

Insulin also helps the body store sugar in the form of glycogen. Glycogen is stored in the liver and muscle, but storage reserves are limited. When a person eats too many carbohydrates that cannot be stored in the liver or muscle for later use, insulin can assist in storing them as fat (as in triglycerides).

Does Eating Sugar Increase Your Risk of Diabetes?

While eating sugar does not automatically cause diabetes, a diet rich in added sugars, saturated fats and excess energy intake is associated with an increased risk of developing diabetes, notes the American Diabetes Association. High-sugar diets are also associated with an increased risk of overweight and obesity, nonalcoholic fatty liver disease and metabolic syndrome.

Caroline Thomason, RD, CDCES, a dietitian in the Washington, D.C. area, adds, “Type 2 diabetes can certainly be impacted by the amount of sugar intake in your diet. Sugar in your diet impacts blood sugar, so it makes sense that increased sugar intake is associated with diabetes risk. However, eating sugar alone isn’t enough to cause diabetes.” In addition, Cheng adds, “How your body makes and uses insulin contributes to your risk of diabetes.”

Added Sugar Guidelines

The Dietary Guidelines for Americans recommends that individuals 2 years and older consume less than 10% of their total daily calories from added sugars. For example, a 2,000-calorie diet would contain no more than 200 calories or about 12 teaspoons of sugar daily.

According to the CDC, sugary drinks are the No. 1 source of added sugar. One 12-ounce soda contains 36.8 grams of sugar (nearly 10 teaspoons), per the USDA. And the American Heart Association sets this limit even further, to no more than 6% of your calories daily, about 6 to 9 teaspoons per day, depending on sex.

Natural Sugars vs. Added Sugars

On a basic level, natural sugars are those that are, as the name implies, naturally found in foods, such as unsweetened dairy products, fruits and vegetables. On the other hand, added sugars are those that have been added to foods during production, such as sugary beverages, dressings and store-bought sauces.

There has been a long debate about whether natural sugar, added sugar, or non-nutritive sweeteners (aka artificial sweeteners) can cause similar effects when it comes to diabetes. This is a complicated comparison because food is usually not eaten in isolation, and most foods contain a variety of nutrients.

For example, fruit contains natural sugar but also offers hydration, vitamins, minerals, fiber and plant-based compounds. Whole fruit is also lower in calories than other foods and beverages that contain added sugar, such as sweetened fruit juice and desserts. A 2021 meta-analysis published in The Journal of Clinical Endocrinology and Metabolism found that higher intakes of fruit were associated with a lower risk of developing type 2 diabetes.

Yet, natural sugar and added sugar can impact blood sugar, which is a natural response to metabolizing sources of carbohydrates. Thomason notes, “Some foods have naturally occurring sugars, like fruit juice or yogurt. While these foods do not count toward your total added sugar intake each day, they do count toward your carbohydrates per meal and can impact blood sugar levels.”

“Even natural sweeteners like honey, fruit juice and maple syrup still contain sugars that can affect blood sugar levels if over-consumed or not balanced with other macronutrients like protein, fat and high-fiber carbs,” she adds.

Controversy over whether artificial sweeteners increase diabetes risk or contribute to excess food intake and weight gain has been debated for years. A 2023 meta-analysis published in the International Journal of Obesity (funded by the American Beverage Association) found that people who drank at least two diet beverages per day versus those who drank water and completely avoided artificially sweetened beverages both lost weight and improved health markers. However, the group that drank diet soda lost 3 pounds more. This doesn’t mean that diet soda is superior to water. More likely, this study suggests that people who consume diet beverages are cutting calories elsewhere, contributing to weight loss.

Audrey Koltun, RDN, CDCES, a registered dietitian and certified diabetes care and education specialist in New York, says, “Artificial sweeteners make foods and beverages taste sweet without adding those extra calories that can contribute to weight gain. In moderation, these can be part of a healthy diet. For example, if someone has prediabetes or diabetes, using artificial sweeteners can make someone feel like they are not on a “diet” all the time without increasing blood sugar.”

Other Risk Factors for Diabetes

The ADA’s Standards of Care in Diabetes recommends that all people begin diabetes screenings at age 35. Other risk factors that indicate testing sooner or more frequently include adults with overweight or obesity (BMI 25 kg/m2 or above, or 23 kg/m2 or above in Asian American individuals) who have one or more of the following risk factors:

First-degree relative with diabetes

High-risk race/ethnicity (e.g., African American, Latino, Native American, Asian American, Pacific Islander)

History of cardiovascular disease

Hypertension (130/80 mmHg or above, or on therapy for hypertension)

HDL cholesterol level below 35 mg/dL (0.90 mmol/L) and/or a triglyceride level above 250 mg/dL (2.82 mmol/L)

Polycystic ovary syndrome

Physical inactivity

Prediabetes

Other clinical conditions associated with insulin resistance (e.g., severe obesity, acanthosis nigricans)

Previous gestational diabetes diagnosis

HIV

How to Eat to Lower Your Risk of Diabetes

Eating to lower your risk of diabetes doesn’t have to be complicated or out of touch with general healthy eating guidelines. Koltun says, “Recommendations for lowering your risk for diabetes are suggested for everyone of all ages and include eating a nutrient-dense diet most of the time as well as getting regular physical activity.”

She suggests, “Incorporating a lot of vegetables and other sources of natural fiber like fruit, beans, lentils, unsweetened oatmeal and whole grains is important. Limiting your intake of refined carbohydrates and sugar and modeling your meals like ‘My Plate’ (plate method) is a great place to start. Break down your plate into one-half vegetables, one-quarter lean protein and one-quarter starch like legumes, whole grains or starchy vegetables like butternut squash or sweet potatoes.”

Thomason concurs with practicing the plate method. She adds, “Protein and veggies will not spike blood sugars and can work to stabilize them as they slow down absorption through the digestive process. Similarly, choosing high-fiber carbs will help slow down the release of carbohydrates into sugars and reduce the total blood sugar spike after a meal.”

According to the ADA, various types of eating styles can assist in preventing diabetes. These include the Mediterranean diet, a plant-forward eating plan, a vegetarian diet and a lower-carbohydrate diet.

The key to finding an eating plan that works for you is to make sure it helps you maintain the pleasure of eating, is customizable to your culture and lifestyle, allows you to meet your nutrient needs, and is sustainable. If you need help finding your ideal eating plan, contact a registered dietitian for guidance.