Person measuring waist while wondering if undiagnosed diabetes can cause weight gain

Can Undiagnosed Diabetes Cause Weight Gain?

Written on June 18, 2023 by Theresa Vuskovich, DMD. To give you technically accurate, evidence-based information, content published on the Everlywell blog is reviewed by credentialed professionals with expertise in medical and bioscience fields.

Table of contents

Key points:

  • 1% to 2% of US adults have undiagnosed diabetes.[1]
  • Unexplained weight loss is often a symptom of diabetes. However, some individuals with undiagnosed diabetes may not experience any symptoms.[2]
  • Weight gain is a risk factor for developing type 2 diabetes (T2D).[3]
  • Undiagnosed diabetes can increase your risk of heart disease, nerve damage, and vision problems.[4]

Diabetes remains one of the leading public health concerns in the United States.[1] Currently, 37.3 million people are living with diabetes, and 96 million US adults have prediabetes.[5] Despite an increase in diabetes awareness in recent years, individuals are still living with undiagnosed diabetes in the US.[5] Approximately 1% to 2% of US adults have undiagnosed diabetes.[1] This article explores diabetes, its symptoms, and risk factors and answers the question, "Can undiagnosed diabetes cause weight gain?"

Understanding Diabetes

Diabetes impairs your body's ability to convert food into energy.[4] When you eat food, your body metabolizes the food into glucose (sugar), resulting in your body releasing insulin (a hormone) from the pancreas.[4] Insulin signals glucose to enter cells, enabling your body to function. If you have too much glucose in your blood or your body stops responding to insulin, sugar remains in your bloodstream, damaging your blood vessels.[4]

There are different types of diabetes, but T2D remains the most prevalent form of diabetes.[4] Other forms of diabetes are type 1 diabetes (T1D) and gestational diabetes (GD).[4] Prediabetes occurs when your blood sugar levels are high but not elevated enough to receive a diabetes diagnosis.[4] However, prediabetes places you at a greater risk of developing T2D.[4] Here is what you need to know about the different forms of diabetes[4,5]:

  • Type 1 diabetes (T1D): T1D is an autoimmune disease that damages insulin-producing beta cells in the pancreas. About 5% to 10% of diabetes diagnoses are T1D. There are genetic and environmental factors contributing to the development of T1D. T1D is generally diagnosed during childhood or adolescence, but you can develop T1D later in life.
  • Type 2 diabetes (T2D): T2D accounts for approximately 90% of all diabetes diagnoses. A person with T2DM cannot maintain blood sugar balance due to the body's diminished response to insulin, causing sugar to remain in the blood. T2D is more common over the age of 45 but can develop at any age. Diabetes is a chronic health condition that requires long-term management with lifestyle changes and medications.
  • Gestational diabetes (GD): GD is defined as elevated blood sugar levels during pregnancy. About 7% of pregnancies are complicated by GD, increasing the risk of both mother and child developing T2D.
  • Prediabetes: Although prediabetes is not considered diabetes, it is important to understand prediabetes because it can lead to T2D. Prediabetes means your body has elevated blood sugar levels, but fortunately, not everyone with prediabetes develops T2D. Improving your diet and physical activity can help you manage prediabetes and prevent T2D. Many individuals with undiagnosed diabetes likely developed undiagnosed prediabetes before advancing to T2D.

The remainder of this article discusses T2D because it is the most common form of diabetes and the most likely to remain undiagnosed.

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Diagnosing Diabetes

T2D is commonly diagnosed in adulthood, but with rising rates of childhood obesity, more children are developing diabetes.[4] The diagnosis of diabetes is based on the results of blood tests interpreted by a healthcare provider.[4] Here are common tests for diagnosing diabetes[4]:

Glycated Hemoglobin (Hb) A1C: The A1C test measures your average blood sugar levels over the previous 2 to 3 months. Individuals with an A1C of over 6.5% are diagnosed as diabetic.

Fasting Plasma Glucose (FPG): The FPG test measures your blood sugar levels after fasting. An FPG over 126 mg/dL indicates diabetes.

Losing Weight is a Common Symptom of Diabetes

Everyone's experience with diabetes symptoms is unique.[2] Some individuals have many symptoms, while others do not experience any.[2] Although weight gain is possible for people with undiagnosed diabetes, it is generally not considered a symptom.[2] According to the Centers for Disease Control and Prevention (CDC), symptoms of diabetes include the following[2]:

  • Frequently urinate (pee), especially at night
  • Feeling thirsty all the time
  • Having unexplained weight loss
  • Feeling very hungry
  • Experiencing blurry vision
  • Feeling numb or tingling in your fingers or feet
  • Experiencing fatigue
  • Having very dry skin
  • Having slow-healing sores
  • Having frequent infections

Gaining Excess Weight is a Risk Factor for Diabetes

Having obesity or excess weight significantly increases your risk of developing T2D.[3] According to the CDC, other risk factors for developing T2D are as follows[3]:

  • Prediabetes
  • Overweight
  • 45 years and older
  • Family member with T2D
  • Physically inactive
  • Gestational diabetes
  • People who are African American, Hispanic or Latino, American Indian, or Alaska Native
  • Non-alcoholic fatty liver disease

Managing Diabetes

The first step towards managing diabetes is getting a diagnosis. Allowing your diabetes to remain undiagnosed can place your health at serious risk. An evaluation and blood tests are required to determine whether you have diabetes. Managing diabetes is possible through lifestyle changes and medications if needed.

Weight Management with Everlywell

Everlywell offers an at-home A1C test to help determine your diabetes risk. Virtual care visits for online weight care are also available via Everlywell. Virtual care visits connect you with a healthcare provider who can discuss diabetes symptoms with you. Care plans are customized for each patient to ensure the best results.

Kidney Disease and Weight Gain: What You Need to Know

Conditions That May Have Weight Gain as a Symptom

Genetic Obesity: What Does It Mean?


  1. Fang M, Wang D, Coresh J, Selvin E. Undiagnosed Diabetes in U.S. Adults: Prevalence and Trends. Diabetes Care. 2022;45(9):1994-2002. doi:10.2337/dc22-0242.
  2. Diabetes symptoms. Centers for Disease Control and Prevention. Published January 20, 2023. Accessed June 12, 2023.
  3. Diabetes risk factors. Centers for Disease Control and Prevention. Published April 5, 2022. Accessed June 12, 2023.
  4. Goyal R, Jialal I. Type 2 Diabetes. StatPearls Publishing; 2023.
  5. Diabetes and prediabetes. Centers for Disease Control and Prevention. Published February 21, 2023. Accessed June 12, 2023.
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