Prediabetes
Videos
Overview
Prediabetes means blood sugar is higher than normal but not yet high enough to be diagnosed as type 2 diabetes. It is defined by an HbA1c of 5.7% to 6.4%, a fasting glucose of 100 to 125 mg/dL, or a two-hour glucose of 140 to 199 mg/dL on an oral glucose tolerance test (American Diabetes Association, Diabetes Care, 2025). More than one in three American adults has prediabetes, and most do not know it.
Prediabetes is not harmless. Without intervention, a substantial proportion of people progress to type 2 diabetes over the following years, and prediabetes itself is associated with higher risks of heart disease, kidney disease and nerve damage (Tabák et al., Lancet, 2012). The good news is that it is highly reversible. In the landmark Diabetes Prevention Program, a lifestyle program achieving about 7% weight loss reduced progression to diabetes by 58%, and metformin reduced it by 31% (Diabetes Prevention Program Research Group, New England Journal of Medicine, 2002).
For people with obesity, newer treatments can be even more powerful: in a semaglutide weight-loss trial, the majority of participants with prediabetes returned to normal blood sugar (Perreault et al., Lancet Diabetes & Endocrinology, 2022), and bariatric surgery has been shown to sharply reduce the long-term risk of developing diabetes (Carlsson et al., Swedish Obese Subjects study, New England Journal of Medicine, 2012).
Why Prediabetes Is a Window of Opportunity
At the prediabetes stage, the pancreas is still producing substantial insulin, and the main problem is insulin resistance driven by excess fat in the liver, muscle and abdomen. Reducing that fat improves insulin sensitivity quickly. Once diabetes is established and insulin production has declined further, reversal becomes harder. Acting during prediabetes is therefore one of the most effective investments in long-term health.
Causes
- Insulin resistance, driven mainly by excess visceral and liver fat; see insulin resistance
- Declining insulin secretion from the pancreas
- Genetics and family history
- Physical inactivity
- Diets high in refined carbohydrates and sugary drinks
- Poor sleep and sleep apnea
Risk Factors
- Overweight or obesity
- Age 35 and older
- Family history of type 2 diabetes
- Hispanic, Black, Asian American or Native American background
- History of gestational diabetes or polycystic ovary syndrome
- High blood pressure or abnormal cholesterol
- Physical inactivity
Who It Affects
Prediabetes affects tens of millions of American adults and a growing number of adolescents with obesity. Guidelines recommend screening adults with overweight or obesity who have additional risk factors, and all adults beginning at age 35 (American Diabetes Association, Diabetes Care, 2025).
Complications
- Type 2 diabetes; see type 2 diabetes
- Heart disease and stroke
- Early kidney and nerve damage (Tabák et al., Lancet, 2012)
- Fatty liver disease
Symptoms
Prediabetes usually causes no symptoms. Possible clues include darkened skin on the neck or armpits (acanthosis nigricans), skin tags, increased thirst or fatigue, and a growing waistline.
Diagnosis
- HbA1c 5.7% to 6.4%
- Fasting plasma glucose 100 to 125 mg/dL
- Two-hour glucose 140 to 199 mg/dL on an oral glucose tolerance test (American Diabetes Association, Diabetes Care, 2025)
- Repeat testing every one to two years, or sooner with weight gain
Differential Diagnosis
- Type 2 diabetes (higher values)
- Medication effects, such as steroids
- Conditions that falsely alter HbA1c, including anemia and some hemoglobin variants
Lifestyle Modifications
- Lose 5% to 7% of body weight, the target used in the Diabetes Prevention Program (Diabetes Prevention Program Research Group, New England Journal of Medicine, 2002).
- Exercise at least 150 minutes per week.
- Reduce refined carbohydrates and sugary drinks; build meals around vegetables, lean protein and fiber.
- Improve sleep and treat sleep apnea.
- Join a structured program, such as a CDC-recognized diabetes prevention program.
Small, consistent changes add up: a 15-minute walk after dinner lowers post-meal glucose, replacing sugary drinks with water can remove hundreds of calories a day, and adding protein to breakfast reduces cravings later in the day.
Treatment Options
- Intensive lifestyle programs (Diabetes Prevention Program Research Group, New England Journal of Medicine, 2002)
- Metformin, particularly for people under 60 with a BMI of 35 or higher or a history of gestational diabetes (American Diabetes Association, Diabetes Care, 2025)
- GLP-1 receptor agonists and tirzepatide for people with obesity, which produce substantial weight loss and frequently restore normal glucose (Perreault et al., Lancet Diabetes & Endocrinology, 2022); see medical weight loss
- Bariatric surgery for people with severe obesity, which markedly lowers future diabetes risk (Carlsson et al., Swedish Obese Subjects study, New England Journal of Medicine, 2012); see bariatric surgery
What the Evidence Shows for Medications and Surgery
In the STEP 1 trial, about 84% of participants with prediabetes who took semaglutide had normal blood sugar after 68 weeks, compared with about 48% on placebo (Perreault et al., Lancet Diabetes & Endocrinology, 2022). In the long-term Swedish Obese Subjects study, people who had bariatric surgery developed type 2 diabetes at roughly one-fifth the rate of matched controls, with the greatest benefit in those who had prediabetes at baseline (Carlsson et al., New England Journal of Medicine, 2012).
When to See a Doctor
Ask for a blood sugar test if you are 35 or older, have overweight or obesity, or have a family history of diabetes. If you have prediabetes, recheck at least yearly.
When to Seek Treatment
Seek prompt evaluation for excessive thirst, frequent urination, blurred vision or unintended weight loss, which may indicate progression to diabetes.
Long-Term Outlook
Maintaining weight loss, staying active and monitoring blood sugar periodically allow most people to prevent or substantially delay type 2 diabetes.
Related Reading and Videos
Read more in our articles Diabetes Remission After Bariatric Surgery: A Complete Patient Guide and GLP1 Medications Explained: Wegovy, Zepbound, Saxenda, and More. Watch Diabetes Gone in DAYS: The Surgery Data Your Doctor Never Told You and Why Gastric Bypass Is the Gold Standard — Results, Risks & Life After Surgery on our video library. Related conditions include Metabolic Syndrome and Overweight. Treatments that may be involved include Duodenal Switch (DS), Gastric Bypass (RYGB) and Sleeve Gastrectomy.
Prognosis
Prediabetes is one of the most reversible stages of metabolic disease. With weight loss and activity, many people return to normal blood sugar, and the benefits of the Diabetes Prevention Program persisted for years (Diabetes Prevention Program Research Group, New England Journal of Medicine, 2002).
Why Choose Dr. de la Cruz-Muñoz
Dr. de la Cruz-Muñoz is a board-certified metabolic and bariatric surgeon whose practice offers medical weight loss with modern medications and bariatric surgery for patients with obesity and prediabetes, helping prevent the progression to diabetes and its complications.
With over 25 years in bariatric surgery, Dr. de la Cruz-Muñoz has completed more than 9,000 bariatric operations. Few surgeons reach that volume, experience that patients with prediabetes can draw on before the disease advances.
Featured Procedures
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FAQ
Prediabetes can often be reversed, and type 2 diabetes is not inevitable. Without treatment, about 10% of people with prediabetes in the U.S. develop diabetes each year (Echouffo-Tcheugui et al., JAMA, 2023). In the China Da Qing study, almost 96% of untreated participants eventually developed diabetes over 30 years (Echouffo-Tcheugui et al., JAMA, 2023).
The good news is that modest, sustained weight loss changes that path. In the landmark Diabetes Prevention Program trial (https://doi.org/10.1056/NEJMoa012512), losing at least 7% of body weight and getting 150 minutes of moderate activity per week, such as brisk walking, cut the risk of developing type 2 diabetes by 58% over 3 years. The benefit lasted for decades: risk was still 24% lower at 21 years (American Diabetes Association, Standards of Care in Diabetes, 2026). Weight loss of 7% to 10% is the threshold most strongly linked to prevention (American Association of Clinical Endocrinology, 2026). Metformin lowered risk by 31% and works best in younger adults, people with a BMI of 35 or higher, and women with prior gestational diabetes (National Institute of Diabetes and Digestive and Kidney Diseases, 2018).
Yes. Both produce larger reductions in diabetes risk than lifestyle changes alone, but the benefit of medication lasts only while it's taken.
- Tirzepatide (Zepbound): In the 3-year SURMOUNT-1 trial (https://doi.org/10.1056/NEJMoa2410819) of adults with obesity and prediabetes, only 1.3% of people on tirzepatide developed type 2 diabetes, compared with 13.3% on placebo, about a 94% risk reduction (Jastreboff et al., New England Journal of Medicine, 2025).
- Semaglutide (Wegovy): In the STEP 1 trial, 84% of participants with prediabetes returned to normal blood sugar after 68 weeks, compared with 48% on placebo (Perreault et al., Diabetes Care, 2022). After semaglutide was stopped, many slipped back into the prediabetes range as weight returned (Wilding et al., Diabetes, Obesity and Metabolism, 2022).
- Bariatric surgery: In the Swedish Obese Subjects study (https://doi.org/10.1056/NEJMoa1112082), surgery reduced the long-term risk of type 2 diabetes by 78% over 15 years. In people with impaired fasting glucose (one form of prediabetes), the reduction was 87% (Carlsson et al., New England Journal of Medicine, 2012). In that group, about 1.3 patients needed surgery to prevent one case of diabetes over 10 years (Sjöström, Journal of Internal Medicine, 2013).
No medication is FDA-approved specifically to prevent diabetes (Echouffo-Tcheugui et al., JAMA, 2023). These treatments are used for patients who also have obesity, and the right choice depends on BMI, other health conditions, and long-term goals.
Early results are promising. MagDI combines a sleeve gastrectomy with a magnet-created duodeno-ileal connection, similar in concept to SADI-S, which is known for strong diabetes improvement. Bringing food to the lower intestine sooner increases GLP-1 and improves insulin sensitivity, and early studies report substantial improvements in blood sugar and reductions in diabetes medications. Because MagDI is a newer procedure, long-term data are still being collected.
Yes. Remission means normal blood sugar levels without diabetes medications. In the DiRECT trial, nearly half of patients who followed an intensive weight-management program achieved remission at one year (Lean et al., Lancet, 2018). Bariatric and metabolic surgery produce higher and more durable remission rates than medical therapy alone, as shown in the STAMPEDE trial (Schauer et al., New England Journal of Medicine, 2017). Remission is most likely when diabetes has been present for fewer years and before insulin is needed. Patients in remission still need regular monitoring because diabetes can return.
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