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Receiving a prediabetes diagnosis can be unsettling. The condition, defined by abnormally high blood sugar, can be a precursor of type 2 diabetes and affect health in other ways. More than two million Australians have prediabetes and are at high-risk of developing type 2 diabetes according to Diabetes Australia.
First piece of advice: Don’t panic. The good news is that your diet and eating patterns can make a huge difference in what happens next. Following an appropriate eating plan can actually help stop or delay the progression of prediabetes to type 2 diabetes. Here’s how to develop a prediabetic eating approach that supports your health today and going forward.
What is a prediabetic diet—and do you need one?
First, let’s back up for a quick look at what prediabetes is - sometimes called borderline diabetes, prediabetes occurs when a person’s blood sugar (glucose) is higher than normal but not quite high enough to be diagnosed as diabetes. Prediabetes often results when the body has trouble using insulin, the hormone that helps move the glucose from food into the body’s cells for energy. As the “pre” implies, prediabetes can progress to type 2 diabetes if it goes unaddressed (about 37% of people with untreated prediabetes develop type 2 diabetes within four years, research has found). Prediabetes also increases a person’s risk for developing heart and kidney disease.
One tricky aspect of prediabetes is that you might not feel any symptoms if you have it. This partly explains why more than 8 out of 10 people living with prediabetes don’t realise they’re affected. So it’s good to know the risk factors, which include carrying extra weight, living a less-than-active lifestyle, and having a family history of diabetes. If you are in a high-risk group, consider speaking with your doctor about a blood screening to learn whether you have prediabetes. Prediabetes is a reversible condition, assures certified diabetes educator Julie Stefanski, RDN (registered dietitian nutritionist), a spokesperson for the US Academy of Nutrition and Dietetics.
Some prediabetes risk factors are beyond our control including having a family history or being over age 45. But the major risk factors are largely manageable, Stefanski says. Citing research from the Diabetes Prevention Program Outcomes study, she notes that people with prediabetes who adopt lifestyle changes such as becoming more active, eating a nutritious diet that emphasises whole foods, and losing weight are significantly less likely to develop type 2 diabetes in the years that follow than people who do not make such changes.
Got all that? Now let’s talk about how nutrition and meal planning can help you manage prediabetes.
Prediabetes and nutrition
If you recently had a blood screening and learned that your results are in the prediabetes range, you might be wondering, “So what am I supposed to eat now?” or even, “Should I quit carbs altogether?”
It makes sense to think about diet: Studies have shown that as part of a healthy lifestyle plan, eating adjustments can work as well as or better than medication for delaying or preventing the onset of type 2 diabetes. That’s a good thing! But the fact is, there’s no one-size-fits-all “prediabetes diet,” according to a 2019 analysis of nutrition research published in Diabetes Care, a journal of the American Diabetes Association (ADA). In a nutshell, it’s best to work closely with your doctor or a medical nutrition specialist to develop an eating approach that works for your health situation.
Luckily, most people with prediabetes don’t need to eat special meals or “ban” certain foods to manage the condition, Stefanski says, a stance supported by the ADA’s analysis. Your care provider likely will encourage you to choose nutritious whole foods that satisfy your appetite and support your overall health, as well as limit processed foods and sweetened drinks that can add to your blood sugar load without filling you up or providing much nutrition.
Although not everyone who develops prediabetes is overweight, extra kilos—particularly in the waist area—often play a role by promoting insulin resistance, explains certified diabetes educator Toby Smithson, RDN. Insulin resistance occurs when the body’s cells become less sensitive to the hormone over time, which can cause sugar to remain in the blood instead of moving into cells for energy. For this reason, a healthy prediabetes diet may be one that supports weight loss, Smithson says.
Even modest weight loss can make a meaningful difference in reducing diabetes risk, notes Jill Weisenberger, RDN. Indeed, a small 2013 clinical trial found that people at risk of developing type 2 diabetes saw significant improvements in insulin response when they lost just 5% to 7% of their body weight.
Foods for a prediabetes eating plan
Figuring out a prediabetes-friendly eating plan might seem daunting given the health concerns at stake. Weisenberger recommends coordinating with your care team to set goals that feel achievable. Again, the objective in most cases would be to choose nutritious, minimally processed foods that nourish your body and support your overall health. Adjustments to your diet might include adding more leafy greens to your favourite meals, swapping refined-grain foods such as white bread and pasta for 100% whole grain versions, and trading sweetened soft drinks for fruit-infused water.
And a note about carbs: Carbohydrates are indeed the source of blood sugar in the body; most carbs we eat break down into glucose to fuel the body’s cells. But having prediabetes doesn’t mean having to swear off all carbs in your diet, Weisenberger says. The healthy approach for most people is to choose the most nutritious sources possible in balance with other food types.
And while no single food can make or break your health, the following are some foods to consider putting on your plate while managing prediabetes:
- Legumes. Whether we’re talking chickpeas, lentils, cannellini or black beans, the complex starch in legumes is balanced by satisfying protein, as well as fibre for a sustaining effect. “Fibre can help with weight loss by slowing the movement of food through the gut, keeping hunger at bay for longer between meals,” Stefanski says. What’s more, she notes, through a fermentation process during digestion, the fibre in legumes also promotes the growth of gut-friendly bacteria that may support healthy blood sugar control.
- Lean protein. Compared with more carb-based foods like bread or cereal, protein-rich foods may help you feel fuller more quickly by activating gut hormones that signal satiety. Just note that protein sources vary in their nutrition makeup. For instance, certain cuts of red meat (think: ribeye steak) contain high levels of saturated fat, which may pose concerns for cardiovascular health. Protein sources that are leaner and/or contain heart-healthy fats include chicken, fish, eggs, tofu, and legumes.
- Whole grains. Food like wholemeal flour, rolled oats, brown rice, barley. In a large Swedish study, volunteers who ate at least 60g of whole grains a day (the amount you might get in two slices of wholemeal bread, depending on brand) were 34% less likely to develop prediabetes or type 2 diabetes over a 10-year period than those who consumed less than 30g of whole grains each day. Interestingly, people in the high-grain group had better insulin sensitivity independent of weight loss, possibly due to some synergistic effect of grains’ fibre, magnesium, selenium, and a number of antioxidants.
- Non-starchy vegetables. Here’s a handy fact: Plant foods that grow above ground—such as broccoli, leafy greens, asparagus, cauliflower, zucchini, tomatoes, and capsicums—are generally lower in carbs than underground growers like root veggies. Given that the less-starchy picks are also super nutritious and generally low in calories, they deserve ample space on your plate, Stefanski says.
- Nuts. There’s a reason crunching on a handful of nuts is so satisfying—they deliver protein, fibre, and healthy plant fats. Nuts also happen to be low in carbs, making them a smart snack for many people keeping tabs on blood sugar, Smithson says. Regularly eating nuts may also improve the body’s glucose control over time, according to a 2014 meta-analysis published in the journal PLoS One, possibly by affecting how the body processes carbs from other sources.
- Dairy. People who include milk, yoghurt, and even cheese in their diets may experience a modest protective benefit when it comes to diabetes risk, according to a 2019 analysis of published research in the journal Advances in Nutrition. The authors note that more studies are needed to figure out why, but early evidence suggests that dairy-specific proteins may improve the body’s insulin response by supporting the synthesis of lean muscle mass, while the calcium found in milk products may have an “anti-obesity” effect that adds to the benefit.
Foods and drinks to consider limiting when you have prediabetes
Most healthy eating approaches allow for occasional treats—and that goes for people managing prediabetes, too. If you’re a fan of any of the following items, consider putting them on your “once in a while” list. Then, make a plan for including them in a way that won’t undermine your health goals.
- Desserts. You might’ve guessed this category would be part of the mix here. In goodies such as cookies, brownies, ice cream, and lollies, added sugar is usually a starring ingredient. Unlike the naturally occurring sugar in, say, an apple, the sweet stuff in confections isn’t slowed or balanced by fibre, Stefanski says. As a result, blood sugar can rise quickly after eating.
- Sugary drinks. Same goes for sugar in liquid form: Sweetened beverages such as non-diet soft drink, sugary tea and coffee drinks, and syrupy cocktails can raise blood glucose without offering much in the way of nutrition. It’s true that fruit juice—as in, 100% juice—is naturally sweet and often contains vitamins and minerals. Just note that juices do not promote the same feeling of fullness as whole fruits do, in part because fibre gets left behind during the squeezing process.
- Commercially made condiments. You’d be wise to check the nutrition label panel of that barbecue sauce (...and salad dressing, and tomato sauce, and teriyaki sauce...) before adding it to your meals. Condiments and sauces can be surprisingly high in added sugars.
- Fried foods. In a large, long-term study published in 2014, men and women who ate fried food one to three times a week had a 6% increased likelihood of developing type 2 diabetes compared with adults who ate fried food less often. Daily fried food intake was linked to a 19% increased incidence. Apart from adding calories that could make weight management challenging, deep frying in oil may alter the chemical structure of a food in a way that affects health, the researchers noted. All the more reason to love your air fryer.
- Refined grains. During the refining process, a grain’s bran is stripped away, reducing levels of fibre, antioxidants, and other nutrients. For this reason, it might be best to limit refined-grain foods like white rice and crackers. Says Weisberger, “I really like to see people trade up in their carbs: white rice for brown rice, biscuits for whole grain toast, and white crackers for whole grain.”
Prediabetic diet plans
All the experts who spoke with WW agree that diet can play a huge role in reversing prediabetes. But there’s no universal formula for what kind of diet works best for that purpose. As you’ll learn in a moment, studies suggest that a variety of eating patterns are correlated with improvements in glycemic control and a reduced incidence of type 2 diabetes. Not every approach makes sense for every person.
So think of the following list of diet plans as, well, food for thought. Your doctor or medical nutritionist can help you create a personalised plan that accounts for your weight-management goals, your overall health picture, and what you actually like to eat.
> DPP Lifestyle Change Program
Remember the Diabetes Prevention Program (DPP) study we mentioned back at the beginning of this article? The DPP lifestyle approach reflects the findings from that research. Participants in the study who received one-on-one coaching to reduce their fat and calorie intake with a goal of losing at least 7% of their body weight—and who also exercised for at least 150 minutes each week—were 58% less likely to develop type 2 diabetes after three years compared with at-risk volunteers who took a placebo and received general advice about diet and physical activity.
Most health experts agree that coupling dietary changes with exercise is an important part of addressing prediabetes. In addition to supporting weight management, physical activity helps glucose move more effectively into cells, helping keep blood sugar within a desirable range, Stefanski says, echoing additional published research.
> Mediterranean diet
This eating pattern favours foods widely enjoyed by people in regions bordering the Mediterranean Sea, including vegetables, legumes, fish, nuts, grains, and unsaturated plant fats such as olive oil. Compared with a typical Australian diet, a Med-style diet generally contains less red meat and dairy. There’s good evidence to suggest that eating in this way may help lower the risk of developing type 2 diabetes and cardiovascular disease, possibly thanks in part to the diet’s emphasis on monounsaturated fat sources over saturated fat sources.
> Low-carb diet
Low-carb diets affect blood sugar in a fairly straightforward way: Limiting carbs means less of what you eat breaks down into glucose, Stefanski says. Low-carb diets vary in their nuances, but most cap carb intake at around 130 grams of carbs in a day, or 26% or less of total calories consumed. A 2015 research review found that in people with type 2 diabetes, low-carb diets were associated with short-term improvements in glycemic control and cardiovascular risk. Nevertheless, the researchers note that this may have been the result of the weight loss volunteers also experienced due to lower calorie intake, not necessarily the effect of restricting carbs themselves.
> Ketogenic diet
The keto diet is a super-low-carb, high-fat plan with moderate protein. It typically contains 70% to 80% of calories from fat, about 10% to 20% protein, and only 5% to 10% carbohydrates—which means very little of what you eat breaks down into glucose energy. Instead, the body enters a metabolic state called ketosis, a phenomenon in which the liver converts stored fat into substances called ketones to serve as a fuel source for cells. Evidence suggests that a medically supervised ketogenic diet in the short term may be more helpful for weight management and glycemic control than a moderate-carb diet for people with prediabetes and type 2 diabetes. But this super-restrictive plan isn’t sustainable for everyone, and long-term adherence tends to be low.
> Vegetarian, vegan, and plant-based diets
Evidence on the benefits of plant-based eating continues to grow—including for people with prediabetes, Smithson says. A 2019 review of studies showed that a plant-based diet high in fruits, vegetables, whole grains, legumes, and nuts can lower the incidence of type 2 diabetes by as much as 30% versus diets higher in animal-derived foods. “Plants contain vitamins, minerals, and a multitude of phytonutrients that work together to help keep us healthy,” Weisenberger says.
Sample meal plan for prediabetes
Meals that help lower the risk of progression from prediabetes to type 2 diabetes can be delicious and simple to prepare. Again, while there’s no one-size-fits-all approach, a prediabetes-friendly meal plan generally includes plant-based foods, lean protein, whole grains, and healthy fats, supporting sustainable weight loss while delivering all the nutrients needed for good health and wellbeing. Here’s a sample of what you might eat in moving toward those great benefits.
Egg white frittata with cheese and veggies
1 slice whole grain toast
Banh mi-style turkey burger and 15 cherry tomatoes
¼ cup shelled pistachios
Baked fish with macadamia herb crust with ½ cup cooked quinoa
1 boiled egg
Apple & spice overnight oats and ¼ cup walnuts
Turkey chilli and ¼ avocado, diced
The upshot: What is the best diet for managing prediabetes?
A wealth of research shows that a healthy pattern of eating can play a powerful role in halting or slowing the progression of prediabetes to type 2 diabetes. Health experts consider prediabetes a reversible condition.
As convenient as it would be to have a surefire formula that told everyone exactly what to eat for reversing prediabetes, there’s no single plan that works for every person. The upside is that you and your care provider can develop a personalised eating plan that supports good glycemic control, takes any additional health concerns into account, and includes lots of foods you actually like to eat. A triple win for health!
Research also indicates that a prediabetes diet works particularly well when coupled with regular physical activity. While it’s important to take prediabetes seriously, you probably don’t have to completely reinvent all your meals or transform into a marathon runner overnight. “The first step is to accept your current risk of type 2 diabetes, then make gradual changes to your diet and lifestyle habits,” Stefanski says. Small measures you take today really do matter—and can put you on the path to better health down the line.
Karen Ansel, MS, RDN, is a journalist and author specialising in nutrition, health, and wellness.
This article was reviewed for accuracy in July 2021 by Michelle Cardel, PhD, MS, RD, director of global clinical research and nutrition at WW. The WW Science Team is a dedicated group of experts who ensure all our solutions are rooted in the best possible research.