Top of the pageDecision Point

You may want to have a say in this decision, or you may simply want to follow your doctor's recommendation. Either way, this information will help you understand what your choices are so that you can talk to your doctor about them.

Prediabetes: Which Treatment Should I Use to Prevent Type 2 Diabetes?

Get the facts

Your options

  • Make major lifestyle changes to help prevent type 2 diabetes.
  • Take the medicine metformin (Glucophage) to help prevent type 2 diabetes.

Key points to remember

  • If you have prediabetes, your blood sugar is higher than it should be. You are more likely to get type 2 diabetes.
  • Major lifestyle changes can help prevent type 2 diabetes in people with prediabetes. These changes include losing weight, eating healthier foods, and getting more exercise.
  • The medicine metformin can also help prevent type 2 diabetes in people with prediabetes.
  • Even if you take metformin, it is important to make as many healthy lifestyle changes as you can. Doing both of these things may give you the best chance of delaying or preventing type 2 diabetes over the long term.
FAQs

What is prediabetes?

Prediabetes means that your blood sugar is higher than it should be, but not high enough to be diabetes. Most people who get type 2 diabetes have prediabetes first.

Why should you avoid type 2 diabetes?

Type 2 diabetes can have a big impact on your life. If you get it, you'll probably have to make some changes. For example, you may have to carefully watch what you eat, take medicine every day, and watch for other health problems.

Over time, diabetes can harm your eyes, nerves, and kidneys. It can damage your blood vessels. This can lead to heart disease, heart attack, and stroke. You could also have nerve damage. In your feet, this nerve damage can cause slow healing and pain when you walk. Your immune system may become weak and less able to fight infections.

How do you prevent type 2 diabetes?

The main way to prevent type 2 diabetes is to lower blood sugar with healthy lifestyle changes. The medicine metformin can also lower blood sugar.

Research shows that:

  • For many people, making major lifestyle changes works better than taking metformin to help delay or prevent type 2 diabetes for up to 10 years.footnote 3, footnote 4 A follow-up study at 15 years showed that making major lifestyle changes was about equal to taking metformin in helping to delay or prevent type 2 diabetes.footnote 5
  • Making major lifestyle changes or taking metformin works very well to delay or prevent type 2 diabetes in:
  • Many people age 60 and older benefit more from making major lifestyle changes. And many people younger than 60 benefit more from taking metformin.footnote 7

For some people, making major lifestyle changes or taking metformin can help delay or prevent type 2 diabetes for up to 15 years.footnote 5

Some people may choose to take metformin and also make major lifestyle changes. Doing both of these things may give you the best chance of delaying or preventing type 2 diabetes over the long term.

What lifestyle changes can help prevent type 2 diabetes?

You may be able to prevent or delay type 2 diabetes without taking medicine.

Studies show that making these three major lifestyle changes make getting type 2 diabetes less likely:footnote 3

  • Losing 7% or more of your weight, if you are overweight. If you weigh 200 pounds, losing 7% of your weight means losing 14 pounds.
  • Getting at least 2½ hours (150 minutes) of moderate activity a week. Moderate activity gets your heart pumping. Examples are walking quickly, shooting baskets, and dancing.
  • Eating a diet low in calories and saturated fat.

Some people may find it helpful to take part in a formal program like the National Diabetes Prevention Program to help them make these changes.

What are the benefits and risks of using lifestyle changes to prevent type 2 diabetes?

Lifestyle changes can:

  • Help you lower blood sugar and prevent type 2 diabetes.
  • Help control or prevent high blood pressure, high cholesterol, and heart disease.
  • Help you feel better overall.

If you start slowly and follow your doctor's advice, there are few risks to making lifestyle changes. Some people do strain muscles or joints when they suddenly become active. But if you gradually increase how much activity you do, you're less likely to get hurt.

Sometimes the lifestyle changes are hard to keep up over time. If you stop doing them, you could raise your chances of getting type 2 diabetes.

What are the benefits and risks of using metformin to prevent type 2 diabetes?

Metformin:

  • Can help you lower blood sugar and prevent type 2 diabetes.
  • Is easy for some people to use. All you do is take medicine every day. But it is still important to make lifestyle changes if you can.
  • Works very well and is generally safe.

Metformin has side effects. When some people first start taking metformin or start taking a larger dose, they feel sick to their stomach, have diarrhea or gas, or lose their appetite. These side effects usually go away after a short time. Or they can be avoided if the dose of metformin is increased slowly.

If you are breastfeeding or planning to get pregnant, you and your doctor can decide if taking metformin is the best decision for you. Metformin is probably safe for breastfeeding women and their babies. footnote 2

Metformin is also used to treat type 2 diabetes. Some people worry that taking metformin to prevent type 2 diabetes may mean that the medicine won't work as well if they get type 2 diabetes later on. But that's not true. Metformin will still work. You don't need to wait to take it.

What do numbers tell us about treatments to prevent type 2 diabetes?

People who made major lifestyle changes were compared with people who took metformin or a placebo and got information about lifestyle changes for type 2 diabetes.

People with prediabetes who get type 2 diabetes with different treatments* footnote 3, footnote 8, footnote 5
Major lifestyle changes Metformin plus information about lifestyle changes for type 2 diabetes Placebo pill plus information about lifestyle changes for type 2 diabetes
After 3 years of follow-up About 14 out of 100 get type 2 diabetes About 22 out of 100 get type 2 diabetes About 29 out of 100 get type 2 diabetes
After 10 years of follow-up About 27 out of 100 get type 2 diabetes About 42 out of 100 get type 2 diabetes About 52 out of 100 get type 2 diabetes
After 15 years of follow-up About 55 out of 100 get type 2 diabetes About 56 out of 100 get type 2 diabetes About 62 out of 100 get type 2 diabetes

*Based on the best available evidence (evidence quality: high)

Making major lifestyle changes or taking metformin both work better than a placebo pill at delaying or preventing type 2 diabetes. For many people, making major lifestyle changes works better than taking metformin to help delay or prevent type 2 diabetes for up to 10 years.footnote 3, footnote 4 A follow-up study at 15 years showed that making major lifestyle changes was about equal to taking metformin in helping to delay or prevent type 2 diabetes.footnote 5

Let's compare people who made major lifestyle changes versus people who took metformin.footnote 3, footnote 8, footnote 5

After 3 years:

  • About 14 out of 100 people who made major lifestyle changes got type 2 diabetes. Compare that to about 22 out of 100 people who took metformin and got type 2 diabetes. That means 8 fewer people got type 2 diabetes after 3 years with lifestyle changes than with metformin.

After 10 years:

  • About 27 out of 100 people who made major lifestyle changes got type 2 diabetes. Compare that to about 42 out of 100 people who took metformin and got type 2 diabetes. That means that 15 fewer people got type 2 diabetes after 10 years with lifestyle changes than with metformin.

After 15 years:

  • About 55 out of 100 people who made major lifestyle changes got type 2 diabetes. Compare that to about 56 out of 100 people who took metformin and got type 2 diabetes. That means that 1 less person got type 2 diabetes after 15 years with lifestyle changes than with metformin.

These numbers apply to many people. But for some people, either making major lifestyle changes or taking metformin works very well to delay or prevent type 2 diabetes. This seems to be especially true for:

Many people age 60 and older benefit more from making major lifestyle changes. And many people younger than 60 benefit more from taking metformin.footnote 7

For some people, making major lifestyle changes or taking metformin can help delay or prevent type 2 diabetes for up to 15 years.footnote 5 But doing both of these things may give you the best chance of delaying or preventing type 2 diabetes over the long term.

Women with prediabetes who've had gestational diabetes and who get type 2 diabetes with different treatments* footnote 1, footnote 6
Major lifestyle changes Metformin plus information about lifestyle changes for type 2 diabetes Placebo pill plus information about lifestyle changes for type 2 diabetes
After 3 years of follow-up About 20 out of 100 get type 2 diabetes About 22 out of 100 get type 2 diabetes About 38 out of 100 get type 2 diabetes
After 10 years of follow-up About 56 out of 100 get type 2 diabetes About 51 out of 100 get type 2 diabetes About 65 out of 100 get type 2 diabetes

*Based on the best available evidence (evidence quality: high)

Making major lifestyle changes or taking metformin both work better than a placebo pill at delaying or preventing type 2 diabetes in women who have had gestational diabetes for up to 3 years. But a follow-up study at 10 years showed that taking metformin works a little better than making major lifestyle changes in helping to delay or prevent type 2 diabetes.

Let's compare women who've had gestational diabetes who either made major lifestyle changes or who took metformin.footnote 1, footnote 6

After 3 years:

About 20 out of 100 women who made major lifestyle changes got type 2 diabetes. Compare that to about 22 out of 100 women who took metformin and got type 2 diabetes. That means 2 fewer women got type 2 diabetes after 3 years with lifestyle changes than with metformin.

After 10 years:

About 56 out of 100 women who made major lifestyle changes got type 2 diabetes. Compare that to about 51 out of 100 women who took metformin and got type 2 diabetes. That means 5 more women got type 2 diabetes after 10 years with lifestyle changes than with metformin.

Understanding the evidence

Some evidence is better than other evidence. Evidence comes from studies that look at how well treatments and tests work and how safe they are. For many reasons, some studies are more reliable than others. The better the evidence is—the higher its quality—the more we can trust it.

The information shown here is based on the best available evidence.footnote 3, footnote 8, footnote 5, footnote 1, footnote 6 The evidence is rated using four quality levels: high, moderate, borderline, and inconclusive.

Another thing to understand is that the evidence can't predict what's going to happen in your case. When evidence tells us that 2 out of 100 people who have a certain test or treatment may have a certain result and that 98 out of 100 may not, there's no way to know if you will be one of the 2 or one of the 98.

What do experts recommend?

The American Diabetes Association (ADA) recommends making major lifestyle changes.

The ADA also suggests taking metformin, especially if you're younger than 60, have a body mass index (BMI) of 35 or more, or have had gestational diabetes.footnote 9

The ADA recommends that you and your doctor talk about the benefits and risks of making lifestyle changes or using metformin to prevent type 2 diabetes and to make a decision based on your personal preferences and overall health.

Compare your options

Compare

What is usually involved?









What are the benefits?









What are the risks and side effects?









Make major lifestyle changes Make major lifestyle changes
  • If you are overweight, you lose at least 7% of your body weight and keep it off.
  • You get moderate activity for at least 2½ hours each week.
  • You eat a diet that is low in calories and saturated fat.
  • Major lifestyle changes can lower blood sugar and help prevent type 2 diabetes.
  • You may avoid short-term digestive problems that metformin can cause.
  • Lifestyle changes can also help control or prevent high blood pressure, high cholesterol, and heart disease.
  • The cost of making lifestyle changes varies from person to person.
  • It may be hard and take some effort to first make and then continue the needed changes.
Take metformin Take metformin
  • You take metformin every day.
  • You try to eat more healthy foods, be active, and lose weight.
  • Metformin can help you lower blood sugar and help prevent type 2 diabetes.
  • Taking medicine every day may be easier for some people than making major lifestyle changes.
  • Metformin is available as a generic medicine. Generic medicines cost less than brand-name medicines.
  • It can be hard to remember to take medicine every day.
  • The medicine may have side effects. These include feeling sick to your stomach, having diarrhea or gas, and losing your appetite. These side effects usually go away after a short time. Or they can be avoided if the dose of metformin is increased slowly.

Personal stories about how others decided to prevent type 2 diabetes

These stories are based on information gathered from health professionals and consumers. They may be helpful as you make important health decisions.

I had gestational diabetes with my last child. I know this puts me at risk for getting type 2 diabetes later on, so I want to do whatever I can to prevent that from happening. My gym offers a diabetes prevention program, and I'm going to sign up for it. I try to eat healthy and exercise, but I think having more information and support will really help.

Lauren, 47

I knew I had to do something when I found out I had prediabetes. My mom had diabetes, and I know what it's like. So I'm really going to work on it. I'm going to set goals for weight loss and exercise. And I want to see a dietitian. I'm confused about what to eat and the best way to lose weight.

Rosa, 54

I'm not sure what to do about prediabetes, but I know I have to do something. I think I'll start with metformin and also try the lifestyle changes. That way, if I'm not great at making changes, I know medicine will help me.

Richard, 71

I'm an active guy, but I know I've got some extra weight. I've tried to lose weight before. But knowing I might get diabetes makes it really important that I lose weight. And my whole family is going to help by making some changes in how we eat. I hope that with everyone's support I can lose the weight and not have to think about using metformin.

Mikhail, 50

I tried lifestyle changes, but I didn't feel I was doing too well with them. I just couldn't find the time for exercise. I don't want to get diabetes, so I'm taking medicine every day. Maybe when things settle down, I'll try to make changes again.

Sandy, 42

What matters most to you?

Your personal feelings are just as important as the medical facts. Think about what matters most to you in this decision, and show how you feel about the following statements.

Reasons to make major lifestyle changes

Reasons to take metformin

I feel confident that I can make the lifestyle changes.

Right now, I'm not able to make or continue lifestyle changes.

More important
Equally important
More important

I don't like to take medicine if I can help it.

If medicine can help me, I'll take it.

More important
Equally important
More important

I worry about medicine side effects.

If I can avoid type 2 diabetes by using medicine, I'll deal with any side effects.

More important
Equally important
More important

I'll start with major lifestyle changes.

I think medicine is more likely to work for me.

More important
Equally important
More important

My other important reasons:

My other important reasons:

More important
Equally important
More important

Where are you leaning now?

Now that you've thought about the facts and your feelings, you may have a general idea of where you stand on this decision. Show which way you are leaning right now.

Making major lifestyle changes

Taking metformin

Leaning toward
Undecided
Leaning toward

What else do you need to make your decision?

Check the facts

1, Is it important to prevent type 2 diabetes?
2, Are there things you can do to help prevent type 2 diabetes?
3, Does either making major lifestyle changes or taking metformin work well to prevent type 2 diabetes?

Decide what's next

1,Do you understand the options available to you?
2,Are you clear about which benefits and side effects matter most to you?
3,Do you have enough support and advice from others to make a choice?

Certainty

1. How sure do you feel right now about your decision?

Not sure at all
Somewhat sure
Very sure

Your Summary

Here's a record of your answers. You can use it to talk with your doctor or loved ones about your decision.

Your decision 

Next steps

Which way you're leaning

How sure you are

Your comments

Your knowledge of the facts 

Key concepts that you understood

Key concepts that may need review

Getting ready to act 

Patient choices

Credits and References

Credits
Author Healthwise Staff
Primary Medical Reviewer Adam Husney MD - Family Medicine
Primary Medical Reviewer Kathleen Romito MD - Family Medicine
Primary Medical Reviewer David C.W. Lau MD, PhD, FRCPC - Endocrinology
Primary Medical Reviewer Heather Quinn MD - Family Medicine

References
Citations
  1. Ratner RE, et al. (2008). Prevention of diabetes in women with a history of gestational diabetes: Effects of metformin and lifestyle interventions. Journal of Clinical Endocrinology and Metabolism, 93(12): 4774–4779. DOI: 10.1210/jc.2008-0772. Accessed March 1, 2019.
  2. Metformin: Drug information (2019). Lexicomp. https://www.uptodate.com/contents/metformin-drug-information. Accessed March 1, 2019.
  3. Diabetes Prevention Resource Group (2002). Reduction in the incidence of type 2 diabetes with lifestyle intervention or metformin. New England Journal of Medicine, 346(6): 393–403. DOI: 10.1056/NEJMoa012512. Accessed May 5, 2015.
  4. Diabetes Prevention Program Research Group, et al. (2009). 10-year follow-up of diabetes incidence and weight loss in the Diabetes Prevention Program Outcomes Study. Lancet, 374(9702): 1677–1668. DOI: 10.1016/S0140-6736(09)61457-4. Accessed May 5, 2015.
  5. Diabetes Prevention Resource Group (2015). Long–term effects of lifestyle intervention or metformin on diabetes development and microvascular complications over 15–year follow-up: The Diabetes Prevention Program Outcomes Study. Lancet Diabetes and Endocrinology, 3(11): 866–875. DOI: 10.1016/S2213-8587(15)00291-0. Accessed September 16, 2015.
  6. Diabetes Prevention Program Research Group (2015). The effect of lifestyle intervention and metformin on preventing or delaying diabetes among women with and without gestational diabetes: The Diabetes Prevention Program Outcomes Study 10-Year Follow-Up. Journal of Clinical Endocrinology and Metabolism, 100(4): 1646–1653. DOI: 10.1210/jc.2014-3761. Accessed May 5, 2015.
  7. Diabetes Prevention Program Research Group, et al. (2006). The influence of age on the effects of lifestyle modification and metformin in prevention of diabetes. Journal of Gerontology, Series A, Biological Sciences and Medical Sciences, 61(10): 1075–1081. Accessed May 5, 2015.
  8. Herman WH, et al. (2013). Effectiveness and cost-effectiveness of diabetes prevention among adherent participants. American Journal of Managed Care, 19(3): 194–202. Accessed May 5, 2015.
  9. American Diabetes Association (2019). Standards of medical care in diabetes—2019. Diabetes Care, 42(Suppl 1): S1–S193. http://care.diabetesjournals.org/content/suppl/2018/12/17/42.Supplement_1.DC1. Accessed March 4, 2019.
You may want to have a say in this decision, or you may simply want to follow your doctor's recommendation. Either way, this information will help you understand what your choices are so that you can talk to your doctor about them.

Prediabetes: Which Treatment Should I Use to Prevent Type 2 Diabetes?

Here's a record of your answers. You can use it to talk with your doctor or loved ones about your decision.
  1. Get the facts
  2. Compare your options
  3. What matters most to you?
  4. Where are you leaning now?
  5. What else do you need to make your decision?

1. Get the Facts

Your options

  • Make major lifestyle changes to help prevent type 2 diabetes.
  • Take the medicine metformin (Glucophage) to help prevent type 2 diabetes.

Key points to remember

  • If you have prediabetes, your blood sugar is higher than it should be. You are more likely to get type 2 diabetes.
  • Major lifestyle changes can help prevent type 2 diabetes in people with prediabetes. These changes include losing weight, eating healthier foods, and getting more exercise.
  • The medicine metformin can also help prevent type 2 diabetes in people with prediabetes.
  • Even if you take metformin, it is important to make as many healthy lifestyle changes as you can. Doing both of these things may give you the best chance of delaying or preventing type 2 diabetes over the long term.
FAQs

What is prediabetes?

Prediabetes means that your blood sugar is higher than it should be, but not high enough to be diabetes. Most people who get type 2 diabetes have prediabetes first.

Why should you avoid type 2 diabetes?

Type 2 diabetes can have a big impact on your life. If you get it, you'll probably have to make some changes. For example, you may have to carefully watch what you eat, take medicine every day, and watch for other health problems.

Over time, diabetes can harm your eyes, nerves, and kidneys. It can damage your blood vessels. This can lead to heart disease, heart attack, and stroke. You could also have nerve damage. In your feet, this nerve damage can cause slow healing and pain when you walk. Your immune system may become weak and less able to fight infections.

How do you prevent type 2 diabetes?

The main way to prevent type 2 diabetes is to lower blood sugar with healthy lifestyle changes. The medicine metformin can also lower blood sugar.

Research shows that:

  • For many people, making major lifestyle changes works better than taking metformin to help delay or prevent type 2 diabetes for up to 10 years.3, 4 A follow-up study at 15 years showed that making major lifestyle changes was about equal to taking metformin in helping to delay or prevent type 2 diabetes.5
  • Making major lifestyle changes or taking metformin works very well to delay or prevent type 2 diabetes in:
    • People who have a BMI of 35 or more.3
    • Women who have had gestational diabetes.1, 6
  • Many people age 60 and older benefit more from making major lifestyle changes. And many people younger than 60 benefit more from taking metformin.7

For some people, making major lifestyle changes or taking metformin can help delay or prevent type 2 diabetes for up to 15 years.5

Some people may choose to take metformin and also make major lifestyle changes. Doing both of these things may give you the best chance of delaying or preventing type 2 diabetes over the long term.

What lifestyle changes can help prevent type 2 diabetes?

You may be able to prevent or delay type 2 diabetes without taking medicine.

Studies show that making these three major lifestyle changes make getting type 2 diabetes less likely:3

  • Losing 7% or more of your weight, if you are overweight. If you weigh 200 pounds, losing 7% of your weight means losing 14 pounds.
  • Getting at least 2½ hours (150 minutes) of moderate activity a week. Moderate activity gets your heart pumping. Examples are walking quickly, shooting baskets, and dancing.
  • Eating a diet low in calories and saturated fat.

Some people may find it helpful to take part in a formal program like the National Diabetes Prevention Program to help them make these changes.

What are the benefits and risks of using lifestyle changes to prevent type 2 diabetes?

Lifestyle changes can:

  • Help you lower blood sugar and prevent type 2 diabetes.
  • Help control or prevent high blood pressure, high cholesterol, and heart disease.
  • Help you feel better overall.

If you start slowly and follow your doctor's advice, there are few risks to making lifestyle changes. Some people do strain muscles or joints when they suddenly become active. But if you gradually increase how much activity you do, you're less likely to get hurt.

Sometimes the lifestyle changes are hard to keep up over time. If you stop doing them, you could raise your chances of getting type 2 diabetes.

What are the benefits and risks of using metformin to prevent type 2 diabetes?

Metformin:

  • Can help you lower blood sugar and prevent type 2 diabetes.
  • Is easy for some people to use. All you do is take medicine every day. But it is still important to make lifestyle changes if you can.
  • Works very well and is generally safe.

Metformin has side effects. When some people first start taking metformin or start taking a larger dose, they feel sick to their stomach, have diarrhea or gas, or lose their appetite. These side effects usually go away after a short time. Or they can be avoided if the dose of metformin is increased slowly.

If you are breastfeeding or planning to get pregnant, you and your doctor can decide if taking metformin is the best decision for you. Metformin is probably safe for breastfeeding women and their babies. 2

Metformin is also used to treat type 2 diabetes. Some people worry that taking metformin to prevent type 2 diabetes may mean that the medicine won't work as well if they get type 2 diabetes later on. But that's not true. Metformin will still work. You don't need to wait to take it.

What do numbers tell us about treatments to prevent type 2 diabetes?

People who made major lifestyle changes were compared with people who took metformin or a placebo and got information about lifestyle changes for type 2 diabetes.

People with prediabetes who get type 2 diabetes with different treatments* 3, 8, 5
Major lifestyle changes Metformin plus information about lifestyle changes for type 2 diabetes Placebo pill plus information about lifestyle changes for type 2 diabetes
After 3 years of follow-up About 14 out of 100 get type 2 diabetes About 22 out of 100 get type 2 diabetes About 29 out of 100 get type 2 diabetes
After 10 years of follow-up About 27 out of 100 get type 2 diabetes About 42 out of 100 get type 2 diabetes About 52 out of 100 get type 2 diabetes
After 15 years of follow-up About 55 out of 100 get type 2 diabetes About 56 out of 100 get type 2 diabetes About 62 out of 100 get type 2 diabetes

*Based on the best available evidence (evidence quality: high)

Making major lifestyle changes or taking metformin both work better than a placebo pill at delaying or preventing type 2 diabetes. For many people, making major lifestyle changes works better than taking metformin to help delay or prevent type 2 diabetes for up to 10 years.3, 4 A follow-up study at 15 years showed that making major lifestyle changes was about equal to taking metformin in helping to delay or prevent type 2 diabetes.5

Let's compare people who made major lifestyle changes versus people who took metformin .3, 8, 5

After 3 years:

  • About 14 out of 100 people who made major lifestyle changes got type 2 diabetes. Compare that to about 22 out of 100 people who took metformin and got type 2 diabetes. That means 8 fewer people got type 2 diabetes after 3 years with lifestyle changes than with metformin.

After 10 years:

  • About 27 out of 100 people who made major lifestyle changes got type 2 diabetes. Compare that to about 42 out of 100 people who took metformin and got type 2 diabetes. That means that 15 fewer people got type 2 diabetes after 10 years with lifestyle changes than with metformin.

After 15 years:

  • About 55 out of 100 people who made major lifestyle changes got type 2 diabetes. Compare that to about 56 out of 100 people who took metformin and got type 2 diabetes. That means that 1 less person got type 2 diabetes after 15 years with lifestyle changes than with metformin.

These numbers apply to many people. But for some people, either making major lifestyle changes or taking metformin works very well to delay or prevent type 2 diabetes. This seems to be especially true for:

  • People who have a BMI of 35 or more.3
  • Women who have had gestational diabetes.1, 6

Many people age 60 and older benefit more from making major lifestyle changes. And many people younger than 60 benefit more from taking metformin.7

For some people, making major lifestyle changes or taking metformin can help delay or prevent type 2 diabetes for up to 15 years.5 But doing both of these things may give you the best chance of delaying or preventing type 2 diabetes over the long term.

Women with prediabetes who've had gestational diabetes and who get type 2 diabetes with different treatments* 1, 6
Major lifestyle changes Metformin plus information about lifestyle changes for type 2 diabetes Placebo pill plus information about lifestyle changes for type 2 diabetes
After 3 years of follow-up About 20 out of 100 get type 2 diabetes About 22 out of 100 get type 2 diabetes About 38 out of 100 get type 2 diabetes
After 10 years of follow-up About 56 out of 100 get type 2 diabetes About 51 out of 100 get type 2 diabetes About 65 out of 100 get type 2 diabetes

*Based on the best available evidence (evidence quality: high)

Making major lifestyle changes or taking metformin both work better than a placebo pill at delaying or preventing type 2 diabetes in women who have had gestational diabetes for up to 3 years. But a follow-up study at 10 years showed that taking metformin works a little better than making major lifestyle changes in helping to delay or prevent type 2 diabetes.

Let's compare women who've had gestational diabetes who either made major lifestyle changes or who took metformin. 1, 6

After 3 years:

About 20 out of 100 women who made major lifestyle changes got type 2 diabetes. Compare that to about 22 out of 100 women who took metformin and got type 2 diabetes. That means 2 fewer women got type 2 diabetes after 3 years with lifestyle changes than with metformin.

After 10 years:

About 56 out of 100 women who made major lifestyle changes got type 2 diabetes. Compare that to about 51 out of 100 women who took metformin and got type 2 diabetes. That means 5 more women got type 2 diabetes after 10 years with lifestyle changes than with metformin.

Understanding the evidence

Some evidence is better than other evidence. Evidence comes from studies that look at how well treatments and tests work and how safe they are. For many reasons, some studies are more reliable than others. The better the evidence is—the higher its quality—the more we can trust it.

The information shown here is based on the best available evidence.3, 8, 5, 1, 6 The evidence is rated using four quality levels: high, moderate, borderline, and inconclusive.

Another thing to understand is that the evidence can't predict what's going to happen in your case. When evidence tells us that 2 out of 100 people who have a certain test or treatment may have a certain result and that 98 out of 100 may not, there's no way to know if you will be one of the 2 or one of the 98.

What do experts recommend?

The American Diabetes Association (ADA) recommends making major lifestyle changes.

The ADA also suggests taking metformin, especially if you're younger than 60, have a body mass index (BMI) of 35 or more, or have had gestational diabetes.9

The ADA recommends that you and your doctor talk about the benefits and risks of making lifestyle changes or using metformin to prevent type 2 diabetes and to make a decision based on your personal preferences and overall health.

2. Compare your options

  Make major lifestyle changes Take metformin
What is usually involved?
  • If you are overweight, you lose at least 7% of your body weight and keep it off.
  • You get moderate activity for at least 2½ hours each week.
  • You eat a diet that is low in calories and saturated fat.
  • You take metformin every day.
  • You try to eat more healthy foods, be active, and lose weight.
What are the benefits?
  • Major lifestyle changes can lower blood sugar and help prevent type 2 diabetes.
  • You may avoid short-term digestive problems that metformin can cause.
  • Lifestyle changes can also help control or prevent high blood pressure, high cholesterol, and heart disease.
  • The cost of making lifestyle changes varies from person to person.
  • Metformin can help you lower blood sugar and help prevent type 2 diabetes.
  • Taking medicine every day may be easier for some people than making major lifestyle changes.
  • Metformin is available as a generic medicine. Generic medicines cost less than brand-name medicines.
What are the risks and side effects?
  • It may be hard and take some effort to first make and then continue the needed changes.
  • It can be hard to remember to take medicine every day.
  • The medicine may have side effects. These include feeling sick to your stomach, having diarrhea or gas, and losing your appetite. These side effects usually go away after a short time. Or they can be avoided if the dose of metformin is increased slowly.

Personal stories

Personal stories about how others decided to prevent type 2 diabetes

These stories are based on information gathered from health professionals and consumers. They may be helpful as you make important health decisions.

"I had gestational diabetes with my last child. I know this puts me at risk for getting type 2 diabetes later on, so I want to do whatever I can to prevent that from happening. My gym offers a diabetes prevention program, and I'm going to sign up for it. I try to eat healthy and exercise, but I think having more information and support will really help."

— Lauren, 47

"I knew I had to do something when I found out I had prediabetes. My mom had diabetes, and I know what it's like. So I'm really going to work on it. I'm going to set goals for weight loss and exercise. And I want to see a dietitian. I'm confused about what to eat and the best way to lose weight."

— Rosa, 54

"I'm not sure what to do about prediabetes, but I know I have to do something. I think I'll start with metformin and also try the lifestyle changes. That way, if I'm not great at making changes, I know medicine will help me."

— Richard, 71

"I'm an active guy, but I know I've got some extra weight. I've tried to lose weight before. But knowing I might get diabetes makes it really important that I lose weight. And my whole family is going to help by making some changes in how we eat. I hope that with everyone's support I can lose the weight and not have to think about using metformin."

— Mikhail, 50

"I tried lifestyle changes, but I didn't feel I was doing too well with them. I just couldn't find the time for exercise. I don't want to get diabetes, so I'm taking medicine every day. Maybe when things settle down, I'll try to make changes again."

— Sandy, 42

3. What matters most to you?

Your personal feelings are just as important as the medical facts. Think about what matters most to you in this decision, and show how you feel about the following statements.

Reasons to make major lifestyle changes

Reasons to take metformin

I feel confident that I can make the lifestyle changes.

Right now, I'm not able to make or continue lifestyle changes.

             
More important
Equally important
More important

I don't like to take medicine if I can help it.

If medicine can help me, I'll take it.

             
More important
Equally important
More important

I worry about medicine side effects.

If I can avoid type 2 diabetes by using medicine, I'll deal with any side effects.

             
More important
Equally important
More important

I'll start with major lifestyle changes.

I think medicine is more likely to work for me.

             
More important
Equally important
More important

My other important reasons:

My other important reasons:

   
             
More important
Equally important
More important

4. Where are you leaning now?

Now that you've thought about the facts and your feelings, you may have a general idea of where you stand on this decision. Show which way you are leaning right now.

Making major lifestyle changes

Taking metformin

             
Leaning toward
Undecided
Leaning toward

5. What else do you need to make your decision?

Check the facts

1. Is it important to prevent type 2 diabetes?

  • Yes
  • No
  • I'm not sure
That's right. Diabetes will have a big impact on your life and may lead to many other problems. It can harm your eyes, nerves, and kidneys. It can lead to heart disease and stroke. And if you get it, you'll probably have to watch what you eat, take medicine, and watch for other health problems.

2. Are there things you can do to help prevent type 2 diabetes?

  • Yes
  • No
  • I'm not sure
That's right. Studies have shown that losing a certain amount of your weight (if you're overweight), getting at least 2½ hours of moderate activity a week, and eating a diet low in calories and saturated fat make getting type 2 diabetes less likely.

3. Does either making major lifestyle changes or taking metformin work well to prevent type 2 diabetes?

  • Yes
  • No
  • I'm not sure
That's right. For some people, making major lifestyle changes or taking metformin can help delay or prevent type 2 diabetes for up to 15 years. But doing both of these things may give you the best chance of delaying or preventing type 2 diabetes over the long term.

Decide what's next

1. Do you understand the options available to you?

2. Are you clear about which benefits and side effects matter most to you?

3. Do you have enough support and advice from others to make a choice?

Certainty

1. How sure do you feel right now about your decision?

         
Not sure at all
Somewhat sure
Very sure

2. Check what you need to do before you make this decision.

  • I'm ready to take action.
  • I want to discuss the options with others.
  • I want to learn more about my options.
 
Credits
By Healthwise Staff
Primary Medical Reviewer Adam Husney MD - Family Medicine
Primary Medical Reviewer Kathleen Romito MD - Family Medicine
Primary Medical Reviewer David C.W. Lau MD, PhD, FRCPC - Endocrinology
Primary Medical Reviewer Heather Quinn MD - Family Medicine

References
Citations
  1. Ratner RE, et al. (2008). Prevention of diabetes in women with a history of gestational diabetes: Effects of metformin and lifestyle interventions. Journal of Clinical Endocrinology and Metabolism, 93(12): 4774–4779. DOI: 10.1210/jc.2008-0772. Accessed March 1, 2019.
  2. Metformin: Drug information (2019). Lexicomp. https://www.uptodate.com/contents/metformin-drug-information. Accessed March 1, 2019.
  3. Diabetes Prevention Resource Group (2002). Reduction in the incidence of type 2 diabetes with lifestyle intervention or metformin. New England Journal of Medicine, 346(6): 393–403. DOI: 10.1056/NEJMoa012512. Accessed May 5, 2015.
  4. Diabetes Prevention Program Research Group, et al. (2009). 10-year follow-up of diabetes incidence and weight loss in the Diabetes Prevention Program Outcomes Study. Lancet, 374(9702): 1677–1668. DOI: 10.1016/S0140-6736(09)61457-4. Accessed May 5, 2015.
  5. Diabetes Prevention Resource Group (2015). Long–term effects of lifestyle intervention or metformin on diabetes development and microvascular complications over 15–year follow-up: The Diabetes Prevention Program Outcomes Study. Lancet Diabetes and Endocrinology, 3(11): 866–875. DOI: 10.1016/S2213-8587(15)00291-0. Accessed September 16, 2015.
  6. Diabetes Prevention Program Research Group (2015). The effect of lifestyle intervention and metformin on preventing or delaying diabetes among women with and without gestational diabetes: The Diabetes Prevention Program Outcomes Study 10-Year Follow-Up. Journal of Clinical Endocrinology and Metabolism, 100(4): 1646–1653. DOI: 10.1210/jc.2014-3761. Accessed May 5, 2015.
  7. Diabetes Prevention Program Research Group, et al. (2006). The influence of age on the effects of lifestyle modification and metformin in prevention of diabetes. Journal of Gerontology, Series A, Biological Sciences and Medical Sciences, 61(10): 1075–1081. Accessed May 5, 2015.
  8. Herman WH, et al. (2013). Effectiveness and cost-effectiveness of diabetes prevention among adherent participants. American Journal of Managed Care, 19(3): 194–202. Accessed May 5, 2015.
  9. American Diabetes Association (2019). Standards of medical care in diabetes—2019. Diabetes Care, 42(Suppl 1): S1–S193. http://care.diabetesjournals.org/content/suppl/2018/12/17/42.Supplement_1.DC1. Accessed March 4, 2019.

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