What kind of prediabetes & diabetes diets are recommended by dietitians?
More than a third of the adult US population has prediabetes (34.5% to be exact). And what makes prediabetes scary is that most people do not even know that they are at risk. Of the 88 million adults who have prediabetes, only 15.3% of them are aware that they have it. Therefore, it’s important to receive an annual physical so that your blood glucose level can be monitored.
Prediabetes refers to when the blood glucose is higher than normal but not yet at the level of diabetes. Generally, prediabetes is defined as when the Hemoglobin A1c (HbA1c) level is between 5.7-6.4%.
The good news is that studies have shown that prediabetes can be reversed by changing eating habits and increasing physical activity. Losing weight in this manner will reduce the hbgA1c level. Diets such as plant-based diet, low-fat diet, Mediterranean diet, Dietary Approaches to Stop Hypertension (DASH) diet, and low carb diet have been known to help achieve these beneficial results.
Dietary Approaches to Stop Hypertension (DASH) diet
Focuses on fruits, vegetables, low-fat dairy products, whole grains, poultry, fish, nuts
Reduces saturated fat, red meat, sodium, sweets, and sugar-containing beverages
Blood pressure and blood glucose level go hand-in-hand as about 6 out of 10 people who have diabetes also have high blood pressure; diabetes damages and hardens the arteries, which causes high blood pressure.
The DASH diet program was developed to focus on reducing hypertension. A study of 31 people who participated for 8 weeks in the DASH eating program revealed that the diet helped reduce body weight by an average of 5.0 kg and their waist circumference by 6.7cm along with a sharp reduction in fasting blood glucose level . When this diet was combined with physical activity (such as adding 15-20 minutes walking a day for 5 days a week , or 30 minutes of higher intensity activity for 3 times a week ), there was even more improvement, not only in weight, blood pressure, and blood glucose levels, but in all lipid markers as well (e.g. reducing cholesterol level).
Focuses on fruits, vegetables, whole grains, olive oil, beans, nuts, legumes and seeds, herbs and spices
Recommends eating fish and seafood at least two times a week
Recommends Moderate portions of poultry, eggs, cheese, and yogurt
Recommends less red meats and sweets, wine in moderation, and lots of drinking water
Focuses on minimally processed, seasonally fresh, and locally grown foods
Studies have shown that the Mediterranean diet does significantly reduce HbA1c levels. For example, in a randomized controlled study , 105 participants who participated in a Mediterranean eating pattern for 1 year lost 6.2kg of weight on average and improved their HbA1c levels by an average of 1.2%. When the diet was combined with a low carbohydrate diet for 12 months, there were even more benefits: 194 overweight patients lost 10.1kg on average and improved their HbA1c levels by 2% .
Low carbohydrate diet
Focuses on consuming more protein (meat, poultry, fish, shellfish, eggs, cheese, nuts, and seeds) and more fat (butter, olives, avocado, oils)
Focuses on vegetables low in carbohydrates (salad greens, broccoli, cucumbers, summer squash) and fruits low in sugar/carbohydrates (berries)
Low carbs diets are the probably most popular diabetes diets. Clinical studies of more than 1 year of a low carbohydrate diet showed significant improvements in HbA1c levels, and some studies sustained a meaningful benefit at 2 years.  Just as we mentioned above, a low carbohydrate diet combined with the Mediterranean diet produced lower weights and HbA1c levels. However, participants in very low carbohydrate diets (<30g of carbohydrates a day) often drop out since such diets are difficult to keep up due to hunger .
🥗 15 g carbohydrate examples
1/3 cup of cooked brown rice
½ English muffins
1 slice of bread
½ cup sweet potatoes
1 small baked potato
3 cups raw vegetables
1.5 cups cooked vegetables
1 kiwi, 1 ¼ cup strawberries
1 cup fat free milk
½ cup ice cream
🥙 An example of eating 60g of carbohydrates in a day
1 slice of bread with peanut butter for breakfast
3 cups raw vegetables and a piece of chicken breast for lunch
1 small baked potato,1.5 cups cooked vegetables, and a piece of salmon for dinner.
🥪 An example of eating 130g of carbohydrates in a day (scholars define low carbohydrate diet as <130g per day)
½ cup oatmeal with ½ cup low-fat milk, and 1 extra small banana for breakfast (37g total)
1 slice of bread with 1 cup chili, and ¾ cup blueberries for lunch (60g total)
1/3 cup brown rice, ½ cup cooked vegetables, and a piece of chicken breast for dinner (30g total)
Low in saturated fat, cholesterol, and sodium
High in fiber, potassium, unsaturated fat including fruits, vegetables, whole grains, nuts, soy products.
The plant-based diet is most commonly defined as the vegan diet (avoiding all flesh foods and animal derived products including milk and eggs), and vegetarian diet (avoiding all flesh foods but including milk and eggs). A 12-week study performed by Korean researchers compared the results of a vegan diet (46 participants who ate whole grains, vegetables, fruits and legumes) and a conventional diet (47 participants). While both groups showed significant reductions in HbA1c levels, the reductions were larger in the vegan group (0.5% improvement vs. 0.2%) . In addition, a 18-week dietary intervention trial found that a low-fat plant-based diet resulted in a significant reduction in HbA1c levels by 0.7% .
Even though these studies showed benefits, they were performed over a fairly short period of time (12 weeks or 18 weeks). Plant-based principles have always been useful in promoting good health. Plant-based meals with a small amount of lean red meat, poultry, and fish would provide sufficient nutrition.
Prediabetes & Diabetes Diets Summary
In summary, the DASH diet, Mediterranean diet, the low carbohydrate diet, and plant-based diet have all proven to be beneficial to prevent and/or control prediabetes. All four diets contain similar concepts: Eat lots of fruits, vegetables, lean proteins (low-fat dairy products, poultry, fish), “good” fat (olive oil, avocado, nuts, seeds), whole grains (but low in carbohydrates), and minimize sodium and sugar consumption.
Personalized and individualized diet plans, based on your goals and comfort level, are the best way to reduce your blood glucose level.