According to the American Diabetes Association (ADA), diabetes was the 7th leading cause of death in the United States in 2019. It is estimated that 1.5 million people will be diagnosed with diabetes this year.
Additionally, 96 million American adults have prediabetes, a common precursor to Type 2 Diabetes Mellitus. Many of these people are unaware that they are prediabetic and may not take action until after diabetes has developed.
This article will delve into what prediabetes is, its common risk factors and signs to look out for, and what nutrition and lifestyle modifications can do to help thwart or delay the progression into Type 2 Diabetes.
What Is Prediabetes?
Simply put, prediabetes is a condition where your blood sugar levels are higher than normal but do not yet meet the range to be classified as diabetes. Approximately 37% of people with prediabetes go on to develop Type 2 Diabetes Mellitus within four years.
Prediabetes is diagnosed in healthcare settings by assessment of blood glucose levels, either in a fasted state or after an oral glucose tolerance test (OGTT), and hemoglobin A1c (HbA1C).
Prediabetes is a condition where your blood sugar levels are higher than normal but are not yet classified as diabetes.
In a fasted state, the patient has refrained from eating and drinking for at least 12 hours before getting their blood drawn.
In the OGTT, the patient will drink a 75-gram oral glucose solution (usually dextrose) and his/her/their blood sugar levels are checked 2 hours after consumption. The HbA1C measures the patient’s average blood sugar levels over a 2-to-3-month period.
The World Health Organization (WHO) classifies the prediabetic range as 110-125 mg/dL for fasting plasma blood sugar levels and 140-199 mg/dL for levels post-OGTT. The ADA categorizes prediabetes as 100-125 mg/dL for fasting glucose, 140-199 mg/dL for levels post-OGTT, and an HbA1C range of 5.6-6.4%.
Fasted blood sugar levels in the prediabetic range are referred to as impaired fasting glucose, while prediabetic OGTT levels are known as impaired glucose tolerance.
If prediabetes is detected early enough, this can stop the progression into Type 2 Diabetes. In some cases, it can even be reversed when fasting and glucose tolerance levels are no longer impaired. This process is typically accomplished through lifestyle interventions such as diet, exercise and medication.
Prediabetes vs Diabetes
Both prediabetes and diabetes are characterized by chronically elevated blood sugar levels.
Diabetes is defined by a fasting plasma glucose level of 126 mg/dL or higher, 200 mg/dL and above for levels post-OGTT, and a HbA1C measurement of 6.5% or higher.
Prediabetes is considered a major risk factor for Type 2 diabetes but is not typically associated with Type 1 Diabetes.
Type 1 Diabetes is an autoimmune condition in which the immune system attacks the beta cells of the pancreas after interpreting them to be foreign invaders.
The beta cells are responsible for the production of insulin, the hormone which reduces glucose levels in the bloodstream. Over time, this renders the pancreas unable to make insulin. Individuals with Type 1 diabetes must rely on the use of external insulin to manage their blood sugar levels for the rest of their lives.
Type 2 Diabetes Mellitus is characterized by insulin resistance, which means that the pancreas secretes sufficient insulin but the body does not respond to it properly.
Essentially, insulin tries to move the glucose out of the blood and into the body’s cells, but its “key” does not work with the cells’ “locks.” With insulin continually locked out and unable to do its job, glucose begins to build up in the bloodstream.
While external insulin may be beneficial for some people with Type 2 Diabetes to manage their condition, others are able to keep their blood sugar levels at bay without it. Unlike Type 1, Type 2 Diabetes is not always an insulin-dependent condition.
Gestational diabetes, a condition where blood sugar levels are chronically elevated during pregnancy, is also considered a major risk factor for the development of Type 2 Diabetes Mellitus.
Risk Factors for Prediabetes
Prediabetes and diabetes share many common genetic and lifestyle risk factors.
- Lack of physical activity/sedentary lifestyle
- History of high blood pressure or heart disease
- Family history of diabetes
- History of elevated blood sugar levels or HbA1C
- History of low HDL (good cholesterol) and high LDL (bad cholesterol)
- Diagnosis of polycystic ovary syndrome (PCOS)
- History of gestational diabetes or giving birth to a baby weighing 9 or more pounds
- Certain ethnicities are at increased risk, including Native American, Hispanic, African American and Asian/Pacific Islander
The ADA recommends that anyone age 45 and over who is overweight and has one or more of the risk factors listed above be screened for diabetes.
The amount and type of carbohydrates you consume at meals and snacks affect blood glucose levels. Refined and processed carbs (such as sodas, sweetened fruit juices, white rice and desserts) are quickly digested, which often leads to spikes in blood sugar levels.
By contrast, whole grain, fiber-rich carbohydrates (such as brown rice, beans, fruits and vegetables) take the body longer to process which can help keep blood sugar levels more stable.
Symptoms of Prediabetes
Unfortunately, prediabetes so often goes undiagnosed because it does not usually have symptoms. However, some people with prediabetes have similar symptoms to those with Type 2 Diabetes Mellitus and in severe cases may already be experiencing diabetes-related complications.
The following symptoms are associated with prediabetes and/or diabetes:
- Excessive thirst
- Frequent urination
- Blurred vision
- Cuts or bruises that are slow to heal
- Tingling, pain, or numbness in the hands and/or feet
- Acanthosis nigricans (dark, thick, velvety skin in body folds and creases)
Diabetes is considered a progressive disease that can escalate to other serious complications like kidney disease, nerve damage (known medically as neuropathy), limb amputations and even death if left untreated.
What Should I Do If I Am Prediabetic?
If you are diagnosed with prediabetes, meet with your healthcare provider and devise an individualized plan that incorporates improving nutrition and physical exercise, and be screened for diabetes every one to two years.
Those with prediabetes and diabetes should engage in regular physical activity. Adults should participate in 150-300 minutes per week of moderate intensity aerobic exercise or 75 to 150 minutes per week of vigorous intensity aerobic physical activity as well as 2 or more days per week of muscle strengthening resistance training.
Prediabetes can typically be reversed through lifestyle interventions such as diet, exercise and medication.
Studies have demonstrated that aerobic exercise increases insulin sensitivity, which means that the body’s cells become more responsive to insulin’s motions to move sugar out of the bloodstream.
There is no single, uniform diet universally recommended for prediabetes or diabetes and each person with these conditions has their own unique set of dietary needs.
However, meals which incorporate healthy fats and protein and avoid excessive portions of carbohydrate foods are generally recommended for keeping blood glucose levels stable. Carbohydrates should be evenly distributed throughout daily meals and snacks, with an aim to select more whole-grain, higher-fiber foods.
Best Nutrition Recommendations for Prediabetes
The ADA recommends using the Diabetes Plate Method to help create nutrient-dense meals that avoid spikes in blood sugar. This method contains the following four steps:
Step 1: Fill Half Your Plate With Non-starchy Vegetables
Examples: asparagus, bell peppers, broccoli, cabbage, carrots, cauliflower, celery, collard greens, cucumber, eggplant, kale, mushrooms, okra, snow peas, spinach, squash, tomatoes.
Step 2: Fill One Quarter of the Plate With Lean Protein Foods
Examples: fish, shellfish, chicken, turkey, lean beef or pork cuts (such as chuck, round or tenderloin), eggs, cottage cheese, tofu, tempeh, edamame, beans, lentils, hummus, nuts, nut butters.
Step 3: Fill the Remaining Quarter With Carbohydrate Foods (Ideally Whole-Grain)
Examples: brown rice, quinoa, popcorn, whole-wheat bread/pasta/tortillas, potatoes, oats/oatmeal, green peas, parsnips, plantain, pumpkin, sweet potato, fruit, dried fruit.
Step 4: Select Water or Low-Calorie Beverage
Examples: unsweetened tea, unsweetened coffee, sparkling water, flavored water without added sugar.
A note that some packaged foods with a “diabetes-friendly” label may still raise blood sugar levels and/or contain sugar alcohols which can have laxative side effects.
Bonus Step: Select a Dietary Pattern
There are also three dietary patterns which have been studied in the scientific literature and may help manage blood sugar levels and prevent the onset of Type 2 Diabetes.
The Mediterranean Diet
The Mediterranean Diet emphasizes whole, unprocessed foods, unsaturated fats like olive oil and nuts, fiber, and richness in nutrients from fresh fruits and vegetables.
It is primarily plant-based with moderate servings of poultry, eggs, and dairy and limited red meat and sweets. The Mediterranean Diet is associated with reducing risk for chronic diseases and contributing to an overall healthy lifestyle.
Components of the Mediterranean Diet, particularly the nutrients in plant-based foods, may help prevent Type 2 Diabetes. A 2017 study revealed consumption of polyphenols, a group of phytochemicals found in foods like fruits, vegetables, legumes, coffee, tea and wine, was correlated with improved insulin sensitivity.
The DASH Diet
Dietary Approaches to Stop Hypertension, known as the DASH diet, is an eating plan designed to lower blood pressure.
It has similarities to the Mediterranean Diet with its focus on fruits and vegetables, whole grains, legumes, and lower-fat meats as well as limits on red meat and processed foods. However, the DASH diet also incorporates reductions in sodium, with 2,300 mg/day permitted on the standard plan and 1,500 mg/day on the lower-salt plan.
While DASH is typically recommended to lower risk of cardiovascular diseases, there is some evidence to suggest it may help prevent diabetes risk as well. A review in Current Hypertension Reports found that the DASH Diet helped improve insulin sensitivity when combined with an exercise and weight loss lifestyle program.
Vegetarian and Vegan Diets
Vegetarian and vegan diets, particularly ones that focus on whole plant foods, are often rich in many beneficial plant-based nutrients. There are many health benefits associated with these diets, including reduced risk for heart disease.
Studies indicate that vegetarian and low-fat vegan diets may improve control of blood sugar and/or reduce diabetes risk. A 2017 meta-analysis review in nutrients found vegetarian diets were inversely correlated with diabetes risk, suggesting that adhering to vegetarianism or veganism may play a role in preventing the development of diabetes.
However, if a vegetarian or vegan diet is done improperly (such as an overreliance on processed carbohydrate foods), it may worsen prediabetes or diabetes.
The Takeaway: Prediabetes and Preventing Type 2 Diabetes
Prediabetes is a wake-up call that your blood sugar levels are higher than they should be. While it may escalate into Type 2 Diabetes, prioritizing nutrition and physical activity may help halt the progression into Type 2 Diabetes or reverse prediabetes altogether.
People with prediabetes and increased predisposition for diabetes should get their blood glucose levels checked on a regular basis. It is essential to work with your doctor and Registered Dietitian (RD) to create a diet, exercise and medication plan best suited for your individual needs and monitor how you are progressing.
The ADA Diabetes Plate Method can be a great starting place for designing balanced meals that keep carbohydrates in check.
It is best to practice portion control with carbohydrate servings, keep carb intake consistent throughout the day, consume carbohydrates with other macronutrients like protein and fat, and prioritize whole-grain and high-fiber carbs over refined and processed ones.
Getting diagnosed with prediabetes can be scary, but it is also an opportunity to make changes that will help you live a healthier life. Intervening early is the best course of action to decrease your likelihood of developing Type 2 Diabetes and diabetes-related complications in the future.
All included information is not intended to treat or diagnose. Always consult your healthcare provider for medical questions and before beginning or changing any dietary, supplementation, and exercise regimen.