What is prediabetes? How do I know if I have it? What do I do once I’ve been diagnosed? Should I be worried? These are questions searched online tens of thousands of times each month. If you’ve been wondering the same things, you are not alone. And if you’ve found yourself at this blog post, you’re in a place of compassion and ethical care.
I’m Erin, a Registered Dietitian, nutrition therapist, and diabetes specialist based in Seattle, Washington. I am fiercely fat-positive and provide care from a Health At Every Size® approach. This post will provide basic facts about prediabetes and share advice on how to care for yourself in a kind and evidence-based way.
What is prediabetes?
Prediabetes is when blood glucose is higher than average on a population level, but not high enough to meet the threshold for type 2 diabetes diagnosis.
The term prediabetes is an oversimplification of what is going on in the body. The body is very complex, and the term prediabetes doesn’t give us a full picture.
I prefer the terms “impaired glucose tolerance” and “impaired fasting glucose”
Those terms are more specific about what is happening. Let’s unpack them. Impaired glucose tolerance means that after consuming carbohydrates, the amount of glucose (sugar) in your blood is higher than what has been deemed normal/healthy for an adult. Your body is not processing the carbohydrates at the expected pace.
Impaired fasting glucose is similar, but instead of checking your blood after ingesting carbohydrates, your blood is checked when you’ve been fasting, often since midnight the night before your test. The blood glucose levels are higher than expected.
So now that we have a general idea of what is going on, let’s talk more about how a prediabetes diagnosis is made, what is important to consider moving forward, and how to best care for your health. Because ‘prediabetes’ is the more commonly used phrase to talk about this condition, I will continue to use it here even though it’s not my favorite!
How exactly is prediabetes diagnosed?
There are three ways that prediabetes can be diagnosed. Note: these are numbers and cutoffs used in the United States by the American Diabetes Association and the CDC. The World Health Organization and other countries (Canada, the UK, and Australia, for example) have higher cutoffs for prediabetes.
A1c is a blood test marker. It reveals the average blood glucose levels over the past 3 months. An A1C of 5.7%-6.4% will elicit a prediabetes diagnosis. Remember, what this means is that over the last three months, your body has not been removing glucose from the blood at the usual rate, so the amount in your bloodstream is higher more of the time.
Fasting glucose is the blood test that measures your blood after fasting overnight. Levels between 100 to 125 mg/dL indicate prediabetes.
OGTT (this stands for oral glucose tolerance test). In this test, your blood is taken before consuming a carbohydrate (glucose) beverage and then 1 hour later, and again 2 hours later. The blood is checked for glucose to see how quickly it is being taken up out of the blood. At two hours, blood glucose levels of 140 to 199 mg/dL would indicate prediabetes.
Does having prediabetes mean something is wrong?
A prediabetes diagnosis doesn’t necessarily mean something is “wrong.” It also doesn’t mean that you will certainly develop diabetes. It is highly individualized! Studies have reported a range of data in terms of how many people progress from prediabetes to type 2 diabetes. In one study, 55%–80% of the participants with prediabetes were no longer in the prediabetes range 10 years later (Forouhi, et al., 2007). A Cochrane review (a standardized, expert review of the research) found that up to 59% of people diagnosed with prediabetes will return to normal within 10 years (Richter, et al., 2018). Other studies show that about 5-10% of people with prediabetes will progress to type 2 diabetes each year, which is a far cry from the way it is often portrayed (Nathan, et al., 2007).
Some people stay in the prediabetes range forever and there’s not necessarily a problem with that; their body processes glucose at a different pace than what is average on a population level. If they are monitored over time and their glucose tolerance stays in that prediabetes range with no other negative side effects, there’s no reason they need to go to great lengths to get it down into the “normal” range unless they are experiencing other side effects that are affecting their health or quality of life.
At the same time, it is also highly individualized in terms of how each body responds to slightly elevated glucose levels. Some bodies notice no differences and it doesn't affect their lives. Others might experience changes in their body, such as their feelings of hunger and fullness, feelings of satiety, energy levels, and body image. If it feels like a concern to you, you absolutely deserve to get help with your relationship with food and body. A diagnosis like prediabetes can certainly throw someone's relationship with food and body off kilter.
I want you to be really wary of the advice that says “you must do everything you can to avoid diabetes!” Unfortunately, it is a common narrative in healthcare. In my experience, it can be really harmful to people who do have diabetes and it’s not a helpful approach for many folks because ultimately it creates more fear and stress. Since stress is known to raise blood sugar (Harris, et al., 2017), remind me again why we’re using this to prevent diabetes…?
If I have prediabetes, what else should I be concerned about?
Some studies show that people with prediabetes (impaired glucose tolerance) have a slightly higher risk of cardiometabolic disease (Ford, 2010; DECODE, 2021).
But prediabetes is not the only risk factor. There are multiple others. You can be on the lookout for: raised triglycerides, low HDL-cholesterol and increased blood pressure. Thankfully, these will probably be measured at your regular annual wellness exams (or when you have appointments to check on your blood glucose levels) so you can discuss the results with your doctor.
Prediabetes might be a signal of something else going on in terms of metabolic processes.
Remember how we said the body is complex? Impaired glucose tolerance isn’t always the root issue. There may be other things going on. You can ask your doctor, “What is the concern with this lab value? If the concern is pre-diabetes, why are we worried about that?” It is good to have your provider explain to you in more depth what their concerns are.
Advice for managing prediabetes- eight helpful and realistic tips
First, ask yourself: how much can I realistically change? We do not want you to compromise your mental or emotional health. We do not want you to give up all pleasure. We don’t want you to be miserable. And we want you to prioritize your eating disorder recovery (if applicable.) We have to keep all that in mind while setting goals for your health journey.
Eat regularly. It is healthy to eat frequent meals and snacks. Don’t intentionally fast for long periods of time. Try to listen to your body’s hunger and fullness cues.
Eat carbs regularly. Include carbohydrates as a healthy and important part of your eating pattern. You should be eating them at every meal and snack.
Pair protein with your carbs (plus fat and fiber, if possible). It helps the body to absorb and process all the nutrients it gets from food when you eat all three macronutrients (protein, carbohydrates, fat) together. You can also be intentional about incorporating foods with fiber. Whole grains, legumes, beans, fruits and vegetables are all fiber-containing foods.
Get enough (good quality) sleep. Sleep is extremely important for your health. Can you make a plan to improve your quality/quantity of sleep each night?
Manage stress and support your nervous system. Frequent stress on your body and mind can have negative effects on your health. Seek out stress-reducing activities and do them often.
Move your body. Movement is healthy. I recommend looking for an activity that you actually enjoy instead of forcing yourself to exercise in a way that you find punishing.If you enjoy it, you’ll be more likely to actually do it, do it often, and get pleasure from it!
Eat fruits and vegetables. It is exhausting and impossible to eat “perfectly.” Instead, just trying to include some fruits and veg every day is a simple goal that can help promote health.
Do I need to lose weight if I have prediabetes?
You have probably heard that losing weight helps prevent diabetes. The DPP (Diabetes Prevention Program) is main source of research cited as supporting that advice. But here’s what the DPP research actually showed:
Participants who engaged in lifestyle changes and had lost weight at the beginning regained most of that weight by 10 years later (DPP, 2009). They reduced their likelihood of developing diabetes, but it is more likely that their lifestyle changes were what reduced their risk rather than the weight loss itself (DPP, 2002).
The group of participants who took metformin had more moderate amounts of weight loss (averaging 5.5 lb) and it was maintained into year 10. They also had reduced likelihood of developing diabetes.
So as you think about this research, I encourage you not to focus on weight lost or gained. A better takeaway is this:
Lifestyle modifications (changes in eating patterns and physical activity) decreased the chance of developing diabetes.
Metformin also helped with reducing the likelihood of diabetes. I have an entire blog post on taking metformin. It’s something you can discuss with your healthcare provider as another possible factor in your approach to managing prediabetes.
So now what?
If you’re looking for more information on diabetes, here’s a great post outlining how sugar doesn’t cause diabetes and here is an Instagram live where I have an honest conversation about prediabetes, diabetes, blood sugar, carbs and more!
References:
Richter, Bernd, et al. "Development of type 2 diabetes mellitus in people with intermediate hyperglycaemia." Cochrane Database of Systematic Reviews 10 (2018).
Forouhi, N. G., et al. "Incidence of type 2 diabetes in England and its association with baseline impaired fasting glucose: the Ely study 1990–2000." Diabetic Medicine 24.2 (2007): 200-207.
Nathan, David M., et al. "Impaired fasting glucose and impaired glucose tolerance: implications for care." Diabetes care 30.3 (2007): 753-759.
Harris, Melissa L., et al. "Stress increases the risk of type 2 diabetes onset in women: A 12-year longitudinal study using causal modelling." PloS one 12.2 (2017): e0172126.
Ford, Earl S., Guixiang Zhao, and Chaoyang Li. "Pre-diabetes and the risk for cardiovascular disease: a systematic review of the evidence." Journal of the American College of Cardiology 55.13 (2010): 1310-1317.
DECODE Study Group, and European Diabetes Epidemiology Group. "Glucose tolerance and cardiovascular mortality: comparison of fasting and 2-hour diagnostic criteria." Archives of internal medicine 161.3 (2001): 397-405.APA
Diabetes Prevention Program Research Group. "10-year follow-up of diabetes incidence and weight loss in the Diabetes Prevention Program Outcomes Study." The Lancet 374.9702 (2009): 1677-1686.
Diabetes Prevention Program Research Group. "Reduction in the incidence of type 2 diabetes with lifestyle intervention or metformin." The New England journal of medicine 346.6 (2002):393-403.