What are diabetes and prediabetes?
Glucose is the main source of fuel for the body's cells. If you have type 1 or type 2 diabetes, your ability to process and use blood sugar is impaired.
Type 1 diabetes
In type 1 diabetes, the pancreas is unable to produce insulin, a hormone that allows sugar in the blood to enter cells. Insulin must be injected instead.
The disease is caused by an autoimmune process in which the body attacks its insulin-producing cells, called beta cells. Although it's usually diagnosed in children, it can start at any age - even in late adulthood.
Type 2 diabetes
Type 2 diabetes is more common, accounting for approximately 90% of diagnoses. Like type 1, it can develop in adults and children. However, it is less common in children and usually occurs in people who are overweight or obese.
In this form of the disease, your pancreas may not produce enough insulin, or your cells may not be able to resist the effects of insulin. Therefore, too much sugar stays in your bloodstream.
Over time, your beta cells degrade as more and more insulin tries to lower your blood sugar. They can also be damaged by high levels of sugar in the blood.
Diabetes can be diagnosed by elevated fasting blood glucose levels or elevated levels of the marker glycated hemoglobin (HbA1c), which reflects 2-3 months of glycemic control.
Before type 2 diabetes develops, blood sugar levels are elevated, but not high enough to be diagnosed as diabetes. This stage is called prediabetes.
Prediabetes is diagnosed when a blood sugar level is 100–125 mg/dL (5.6–6.9 mmol/L) or an HbA1c level is 5.7–6.4%.
While not everyone has prediabetes, it is estimated that about 70% of people will eventually develop type 2 diabetes.
What's more, even if prediabetes never develops into diabetes, people with the condition are still at higher risk for heart disease, kidney disease and other complications related to high blood sugar.
How does food affect blood sugar levels?
And one of the biggest factors is diet.
Among the three major nutrients, carbohydrates, protein and fat, carbohydrates have the greatest impact on blood sugar. That's because your body breaks down carbohydrates into sugar, which enters your bloodstream.
This happens with all carbohydrates, from refined foods like chips and cookies, to healthy foods like fruits and vegetables.
However, whole foods contain fiber. Unlike starch and sugar, naturally occurring fiber does not increase blood sugar levels and may even slow this rise.
When people with diabetes eat foods high in available carbohydrates, their blood sugar levels rise sharply. High carbohydrate intake often requires high doses of insulin or diabetes medications to control blood sugar.
Given their inability to produce insulin, people with type 1 diabetes require multiple daily injections of insulin, regardless of what they eat. However, eating fewer carbohydrates can significantly reduce mealtime insulin doses.
Carbohydrate restriction for diabetes
Many studies support the use of carbohydrate restriction in people with diabetes.
Low carb, ketogenic diet
A diet very low in carbohydrates usually causes mild to moderate ketosis, a condition in which your body uses ketones and fat instead of sugar as its primary energy source.
Ketosis usually occurs when the daily intake of total carbohydrates or digestible carbohydrates (total carbohydrates minus fiber) is less than 50 or 30 grams. This is equivalent to a 2,000-calorie diet containing no more than 10 percent calories.
Long before the discovery of insulin in 1921, patients with diabetes had been formulating low-carbohydrate, ketogenic diets.
Multiple studies have shown that limiting carbohydrate intake to 20 to 50 grams per day can significantly lower blood sugar levels, promote weight loss and improve heart health in people with diabetes. Furthermore, these improvements usually come quickly.
For example, in one study of patients with obesity and diabetes, limiting carbohydrates to 21 grams per day for 2 weeks resulted in spontaneous reductions in caloric intake, lower blood sugar levels, and a 75% increase in insulin sensitivity. .
In a small 3-month study, people consumed a calorie-restricted low-fat or low-carbohydrate diet, consuming up to 50 grams of carbohydrates per day. The low-carb group had an average 0.6% reduction in HbA1c and twice as much weight loss as the low-fat group. What's more, 44% of them stopped taking at least one diabetes medication, compared with 11% of the low-fat group.
In fact, in some studies, the use of insulin and other diabetes medications has been reduced or discontinued due to improved blood sugar control. A diet containing 20–50 grams of carbohydrates has also been shown to lower blood sugar levels and reduce the risk of the disease in people with prediabetes.
In a small 12-week study, men with obesity and prediabetes received only 30 grams of carbohydrates per day on a Mediterranean diet. Their fasting blood sugar dropped to an average of 90 mg/dL (5 mmol/L), well within the normal range. Additionally, these men lost an astonishing 32 pounds (14.5 kilograms) on average and experienced significant reductions in triglycerides, cholesterol, and blood pressure, among other benefits. Importantly, these men no longer met criteria for metabolic syndrome due to decreases in blood sugar, weight and other health markers.
Despite concerns that higher protein intake on a low-carbohydrate diet may cause kidney problems, a recent 12-month study found that very low carbohydrate intake does not increase the risk of kidney problems Risk of disease.
Low carb diet
Many low-carb diets limit carbohydrates to 50-100 grams per day, or 10-20% of calories.
Although there are few studies on carbohydrate restriction in people with type 1 diabetes, those that do exist report impressive results.
In a long-term study of people with type 1 diabetes who restricted carbohydrates to 70 grams per day, participants saw their HbA1c drop by an average of 7.7% to 6.4%. Moreover, their HbA1c levels remained unchanged after 4 years.
A 1.3% reduction in HbA1c is a significant change that lasts several years, especially for people with type 1 diabetes.
One of the biggest concerns for people with type 1 diabetes is hypoglycemia, which is when blood sugar drops to dangerously low levels.
In a 12-month study, adults with type 1 diabetes who restricted their daily carbohydrate intake to less than 90 grams experienced 82% fewer hypoglycemic episodes than before starting the diet.
People with type 2 diabetes may also benefit from limiting their daily carbohydrate intake.
In a small 5-week study, men with type 2 diabetes who consumed a high-protein, high-fiber diet with 20% of their calories from carbohydrates had an average 29% lower fasting blood sugar.
Moderate carbohydrate diet
A more moderate carbohydrate diet provides 100–150 grams of digestible carbohydrates per day, or 20–35% of calories.
Some studies looking at this type of diet report good results in people with diabetes.
In a 12-month study of 259 people with type 2 diabetes, those who followed a Mediterranean diet (consuming 35% or fewer calories from carbohydrates) had a significant reduction in HbA1c on average - from 8.3% to 6.3%.
Find the right range
Research has proven that various types of carbohydrate restriction can effectively lower blood sugar levels.
Since carbohydrates increase blood sugar, lowering them to any level can help control blood sugar levels.
For example, if you currently consume about 250 grams of carbohydrates per day, reducing your intake to 150 grams can significantly lower your blood sugar after meals.
That said, severely limiting carbohydrate intake to 20 to 50 grams per day appears to have the most dramatic effects, even reducing or even eliminating the need for insulin or diabetes medications.
Avoid high carbohydrate foods
However, you should avoid the following high-carbohydrate foods:
- Breads, waffles, rolls and bagels
- Pasta, rice, corn and other grains
- Potatoes, sweet potatoes, yams and taro
- Milk and sweet yogurt
- Most fruits, except berries
- Cakes, cookies, pies, ice cream and other desserts
- Snack foods such as pretzels, chips and popcorn
- Juice, soda, sweetened iced tea, and other sweetened beverages
Remember, not all of these foods are unhealthy. For example, fruit may be nutritious. However, they are not the best choice for people trying to control blood sugar levels by cutting back on carbohydrates.
Is a low-carb diet always best for diabetes?
Low-carb diets have consistently been shown to lower blood sugar and improve other health markers in people with diabetes. Meanwhile, certain high-carbohydrate diets are thought to have similar effects. For example, some studies show that a low-fat vegetarian or vegan diet can improve blood sugar control and overall health.
In a 12-week study, a brown rice-based vegan diet contained 268 grams of carbohydrates per day (72% of calories) compared to a standard diabetic diet, which contained 249 total daily carbohydrates. grams (64% of calories) lowered participants' HbA1c levels. calories).
An analysis of 4 studies found that people with type 2 diabetes who followed a low-fat Nature's Macrobiotic Diet diet consisting of 70 percent carbohydrates significantly lowered blood sugar and other health markers.
The Mediterranean diet may also improve blood sugar control and provide other health benefits for people with diabetes. However, it is important to note that these diets were not compared directly to low-carbohydrate diets, but to standard low-fat diets often used for diabetes management. Additionally, more research is needed on these diets.
How to determine optimal carbohydrate intake
Although research shows that many different levels of carbohydrate intake may help control blood sugar, the optimal amount varies from person to person.
The American Diabetes Association (ADA) once recommended that people with diabetes get approximately 45% of their calories from carbohydrates. However, the ADA now advocates a personalized approach in which ideal carbohydrate intake takes into account your dietary preferences and metabolic goals. It's important to eat carbs that will feel the best and last long. Therefore, determining how many carbs to eat requires some testing and evaluation to find the ones that work best for you. To determine your ideal carbohydrate intake, measure your blood sugar using a glucometer before and 1-2 hours after a meal. To prevent damage to blood vessels and nerves, the highest level your blood sugar should reach is 139 mg/dL (8 mmol/L).
However, you may want to go even lower.
To reach your blood sugar goals, you may need to limit your carbohydrate intake to less than 10, 15, or 25 grams per meal. Also, you may find that your blood sugar rises more at certain times of the day, so your carb limit for dinner may be lower than for breakfast or lunch. Generally, the fewer carbs you consume, the smaller your blood sugar will rise and the less diabetes medication or insulin you'll need to stay within a healthy range. If you take insulin or diabetes medications, it's important to talk with your healthcare provider before reducing your carbohydrate intake to ensure proper dosing.
If you have diabetes, reducing your carbohydrate intake may be beneficial. Multiple studies have shown that consuming 20-150 grams of carbohydrates per day, or 5-35% of calories, not only improves blood sugar control but also promotes weight loss and other health improvements. However, some people can accommodate more carbohydrates than others. Testing your blood sugar and paying attention to how you feel at different carbohydrate intakes can help you find your optimal diabetes control range, energy levels, and quality of life.