Low Carb and Diabetes: What the Evidence (and American Diabetes Association) Say
From the American Diabetes Association’s (ADA) nutrition guidance to clinical trials and a real-world 90-gram carb approach, here’s how carbohydrate reduction can improve glycemic control, reduce meds and support sustainable weight loss if you have prediabetes and type-2 diabetes.
What is Diabetes?
The World Health Organization (WHO) defines diabetes as a chronic, metabolic disease characterized by elevated blood glucose (blood sugar) levels, which may lead to serious damage to the heart, blood vessels, eyes, kidneys and nerves. The most common kind of diabetes is type-2 diabetes, which happens when your body becomes resistant to insulin or doesn’t make enough insulin.
Type-1 diabetes is a chronic condition where the pancreas produce little or no insulin by itself.
According to the ADA, most people who develop type-2 diabetes almost always have prediabetes—blood sugar levels that are higher than normal but not high enough to be diagnosed as diabetes. You may have some symptoms or even complications of diabetes.
While there are three commonly types of diabetes (see below), when we talk about diabetes in the context of Atkins, we are typically referring to type-2 diabetes or even pre-diabetes.
The Three Types of Diabetes
- Type-1 diabetes: This happens when your pancreas can’t make insulin, leading to high blood sugar. If you have type-1 diabetes, you must take insulin to help control your blood sugar. Type-1 diabetes is most often diagnosed in childhood.
- Type-2 diabetes: This happens when your pancreas doesn’t make enough insulin, or your body can’t process insulin effectively. Having overweight or obesity heightens your risk of this type of diabetes, and it can happen to a person of any age.
- Gestational diabetes: This occurs during pregnancy in some women when hormone changes prevent insulin from working properly. You may need to take insulin, but the condition also may resolve after childbirth.
Nutrition is Not “One-Size-Fits-All” and May Help Manage Diabetes
Mainstream medicine has failed to make much progress when it comes to preventing diabetes. The rates continue to climb, as well as the healthcare costs associated with diabetes, despite all the pharmaceutical and digital interventions on the market, making it clear that the current approaches may not be effectively addressing the root causes of the disease. This is where the role of diet, particularly a low-carb diet, becomes critically important.
The ADA’s Nutrition Consensus Report found that strong evidence supports the efficacy and cost-effectiveness of nutrition therapy as a component of quality diabetes care, including its integration into medical management.
One of the main findings is that a “’one-size-fits-all’ eating plan is not evident for the prevention or management of diabetes” and that carbohydrates play an important role because of their impact on blood sugar. The ADA’s understanding that nutrition is not a “one-size-fits-all” approach is right in line with what we’ve been saying in the world of low carb for years.
Why a Low Carb Diet May Be the Best Diet for Weight Loss and Diabetes
According to the CDC, over 50 percent of US adults in this country have diabetes or prediabetes, and the ADA recognizes that one of the most important factors in treating diabetes or improving health for a diabetic person is weight loss. The authors of Low Carbohydrate Nutritional Approaches in Patients with Obesity, Prediabetes and Type-2 Diabetes state that “Low carbohydrate eating patterns are recognized in scientific literature and expert treatment guidelines as effective nutritional therapies for obesity, prediabetes and type-2 diabetes.”This supports ADA’s Standards of Medical Care, which states, “Reducing overall carbohydrate intake for individuals with diabetes has demonstrated the most evidence for improving glycemia (blood sugar) and may be applied in a variety of eating patterns that meet individual needs and preferences. For individuals with type 2 diabetes not meeting glycemic targets or for whom reducing glucose-lowering drugs is a priority, reducing overall carbohydrate intake with a low or very low carbohydrate eating pattern is a viable option.”
12 Reasons a Low Carb Diet May Help Manage Diabetes
A group of 26 physicians and nutrition researchers, in a review paper submitted to the journal Nutrition, listed 12 reasons, backed by clinical studies, why a low carb diet is beneficial for managing type-2 diabetes. They include:
- High blood sugar is the most important feature of diabetes control. Decreasing carbohydrate intake has the greatest effect on blood sugar levels.
- Increase in calorie intake and obesity has been driven by increases in carbohydrate intake.
- Carbohydrate restriction provides benefits regardless of weight loss.
- Carb restriction is the most reliable dietary intervention for weight loss.
- Adherence to low-carb diets in Type-2 diabetes is as strong as other dietary interventions and is often significantly stronger.
Generally, replacing carbs with protein is beneficial.
- Increased total fat and saturated fat intake are not associated with increased heart disease risk.
- Carbohydrates—not dietary fats—control triglyceride levels.
- HbA1c—also known as glycated hemoglobin, and an indicator of blood sugar levels—is the greatest predictor of microvascular and macrovascular complications in patients with Type-2 diabetes.
- Lowering carb intake is the most effective method for decreasing triglyceride levels and raising levels of “good” HDL cholesterol.
- Patients with diabetes reduce their dependence on, or doses of, medication when following a low-carb diet.
- Intensive blood glucose reduction though carb restriction has negligible side effects compared with the use of medication for the same effect.
Small Changes, Big Results: Atkins 100 and Diabetes
You don’t have to go super low carb to experience the positive health and weight loss benefits of a low carb diet, as shown by a study in the journal Nature where people with type-2 diabetes followed an Atkins 100-style low carb diet:
- Patients with type-2 diabetes were put on a randomized, controlled trial for 18 months where they followed one of two diets:
- A low carb diet, where the daily carbohydrate was limited to less than 90 grams a day (six servings of carbohydrates) without any calorie restriction.
- A traditional diabetes diet, where the daily caloric intake was determined by individual BMI, with a macronutrient distribution of 50 to 60% carbohydrates, 1-1.2 grams/kilograms/day of protein and less than 30% fat.
- After 18 months, the patients agreed to continue their diet and were followed for one year.
- At the one-year follow-up, the patients on the low carb diet showed prolonged and better outcomes on glycemic control, liver function and the use of diabetes medications compared to the patients on the traditional diabetic diet.
The authors concluded that the low carb diet (90 grams of carbohydrates a day) “is an effective and feasible choice for diet control in type-2 diabetes patients.”
Why Don’t More Doctors Recommend Low Carb?
Despite the evidence, many doctors still do not recommend a low carb diet as an effective approach to managing diabetes. This could be due to several reasons:
- Misguided guidelines: The government’s Dietary Guidelines still prioritize high-carbohydrate, low-fat diets, partly because they have been the standard recommendation for decades. However, even the government acknowledges that the Dietary Guidelines aren’t intended for disease management or treatment.
- Lack of nutrition education: Doctors often receive limited training in nutrition during their medical education, making them less likely to prescribe dietary changes over pharmaceutical interventions.
- Pharmaceutical influence: The pharmaceutical industry plays a significant role in diabetes management, focusing heavily on medication rather than dietary solutions.
5 Tips for Adopting Low Carb for Managing Diabetes
If you’re considering a low-carb diet to manage or prevent diabetes, here are some tips to get started:
- Talk to your doctor: While many physicians may not prioritize low carb, it’s still important to consult a healthcare provider or a dietitian who can help tailor the diet to your specific needs.
- Pick your plan: Each Atkins plan (there are three, depending on whether you want to eat 20, 40, or 100 grams of Net Carbs a day) has a customized meal plan and clear-cut steps to help you achieve your goals, whether you're working toward wellness goals, want to lose weight, or would like to manage your diabetes.
- Start slowly: Let your Atkins plan help you reduce your intake of high-carb foods like bread, pasta, and sugary snacks. Replace them with low carb alternatives such as nutrient-rich, high-fiber vegetables, lean proteins, some fiber-rich grains, and nuts and seeds.
- Monitor your blood sugar: Regularly check your levels to see how your body responds to dietary changes. This can help you and your doctor adjust your plan as needed.
- Stay hydrated: You may lose more water as your body adjusts to a low-carb diet.
The Future of Low Carb
The research on low carb is compelling, powerful and continues to evolve—the puzzle pieces are coming together. Right now, there are more than 100 clinical studies that support a low carb lifestyle and its impact on weight loss and managing or eliminating a variety of health issues, and major health organizations are on board.
Jon Clinthorne, PhD
Sr. Director of Nutrition