November is American Diabetes Month and an important time to consider this disease that continues to rise in prevalence. As people age, the risk of developing type 2 diabetes increases. The Centers for Disease Control and Prevention (CDC) estimates that approximately 30% of adults ages 65 and older in the United States have diabetes, while almost 50% have prediabetes. The American Diabetes Association defines prediabetes as a stage where blood glucose levels are higher than normal but not high enough to be diagnosed as diabetes. If prediabetes progresses into diabetes, it could lead to further complications such as nerve damage, vision changes and kidney disease. Therefore, screening (see Table 1, below) is important for prediabetes and recommended for adults ages 45 and older, which may allow for early detection, diagnosis, and intervention to improve health outcomes.
Table 1. Prediabetes and Diabetes Reference Ranges
| Testing | Normal Range | Prediabetes Range | Diabetes Range |
| Fasting Plasma Glucose | Less than 100 mg/dL | 100–125 mg/dL | 126 mg/dL or higher |
| Oral Glucose Tolerance Test (2-hour value) | Less than 140 mg/dL | 140–199 mg/dL | 200 mg/dL or higher |
| Hemoglobin A1C | Less than 5.7% | 5.7–6.4% | 6.5% or higher |
Here’s the good news—prediabetes can be effectively managed, and in many cases, blood glucose levels can return to a normal range. Lifestyle changes, especially related to nutrition and physical activity, are key to achieving this goal.
The Diabetes Prevention Program offers clear evidence that lifestyle changes can make a difference in adults at risk of diabetes. A study of this program followed more than 3,200 at-risk adults and found that participants who adopted an intensive lifestyle intervention, focusing on modest weight loss through healthy eating and regular physical activity, reduced their risk of developing type 2 diabetes by 58%. For adults ages 60 and older, the risk reduction was even greater at 71%.
The lifestyle intervention emphasized the following goals:
- Losing 5%–7% of body weight
- Engaging in at least 150 minutes of moderate physical activity per week
- Adopting a nutrient-dense, lower-calorie, lower-fat diet
These changes not only delayed or prevented the onset of diabetes but also improved cardiovascular health, mobility and quality of life over the long term.
The Role of Diet Quality in Prediabetes Management
While calorie reduction is often emphasized for weight loss, what we eat matters to maintain diet quality. The emphasis should also include nutrient-dense foods and being mindful of added saturated fats, sugar and sodium. For older adults, diet quality becomes even more important due to changing metabolism, appetite, and nutrient absorption. Choosing high-quality foods ensures that every bite counts toward better health and supports a more stable blood sugar response.
The Dietary Guidelines for Americans (DGA) recommend dietary patterns that emphasize:
- Fruits and vegetables: incorporate a variety of fruits and vegetables from all types, including dark green leafy vegetables, legumes (beans, peas, and lentils) and other vegetables. Focus on consuming whole fruit (fresh, frozen, canned in fruit juice) over fruit juices whenever possible.
- Grains: make at least half of your grain choices whole grains over refined grains.
- Lean proteins: incorporate seafood, poultry, legumes, and nuts.
- Low-fat or fat-free dairy: choose 1% or skim milk, low-fat yogurt and cottage cheese, and/or fortified dairy alternatives (e.g., soy milk or yogurt).
- Oils: select oils low in saturated and trans fats (e.g., olive and canola oil, nuts and seafood sources).
This approach promotes diet quality with nutrient-dense foods, high in vitamins, minerals, fiber, protein and/or other beneficial nutrients with relatively fewer calories. Nutrient-dense foods help individuals meet their nutritional needs without excess calorie intake and support blood sugar response.
Understanding Blood Sugar Response
To better understand how nutrition influences blood sugar, it’s helpful to understand how the body processes calories from the diet, specifically carbohydrates. Not all carbohydrates are created equal, and the impact of a food or meal on blood glucose can vary widely depending upon its composition. This is where choosing complex vs. simple carbohydrates may be beneficial.
When simple carbohydrates are digested, they are absorbed quickly into the bloodstream, which can lead to rapid spikes in blood sugar. While complex carbohydrates are digested more slowly, promoting a lower response/spike in blood sugar.
- Complex carbohydrates: Slower rise in blood sugar (e.g., lentils, oats, non-starchy vegetables, brown rice, and sweet potatoes).
- Simple carbohydrates: Rapid spike in blood sugar (e.g., white bread, sugary cereals, candy, and honey).
However, blood sugar response isn’t only influenced by individual foods, but also by how they are consumed. The presence of additional food components such as fiber, protein and fats can slow digestion and glucose absorption, leading to a more gradual rise in blood sugar. For example, pairing a banana (carbohydrate) with nuts (fiber and fat). This provides a balanced snack option to support a slower rise in blood sugar.
Understanding these interactions can empower older adults with prediabetes to make more informed food choices that support stable energy, better glucose control, and long-term metabolic health. By focusing on balanced meals and snacks that include a mix of nutrients and fiber, older adults can reduce post-meal glucose spikes and improve overall diet quality.
Check out these additional resources for more information:
- The American Diabetes Association’s comprehensive Nutrition Therapy Consensus Report provides guidance for healthcare professionals about individualizing nutrition therapy for adults with prediabetes or diabetes.
- What to Eat with Prediabetes or Type 2 Diabetes provides patients information on how to continue to enjoy foods when living with prediabetes or diabetes.
- Are All Carbs Equal? provides patients information on differences in carbohydrate choices.
Michelle Mills, MBA, RDN, LD, is a Senior Nutrition Scientist and Carley Rusch, PhD, RDN, LDN, is a Medical Science Liaison for the Nutrition Division of Abbott, in Columbus, Ohio.
