A low carb diet and diabetes health are more closely linked than you might think. By cutting back on certain carbohydrates, you can often lower your blood sugar, lose weight, and reduce your need for medication in a surprisingly short time. If you have type 2 diabetes or prediabetes, or you are simply concerned about your blood sugar, understanding how low carb eating works gives you another tool you can use alongside your healthcare team.
Below, you will see how a low carb diet can improve your diabetes health quickly, what the research says, and how you can start safely.
Understand what “low carb” really means
Before you change how you eat, it helps to know what counts as “low carb” in the research on diabetes.
A low carb diet usually means reducing your daily carbohydrate intake to less than 130 grams, or under about 26 percent of your total calories, according to Diabetes UK in 2024 (Diabetes UK). Very low carb, or ketogenic, diets are stricter and typically keep carbs below 10 percent of your calories, which is often under 50 grams per day (Healthline).
What matters most for your diabetes health is not only the number of carbs but also the types of carbs you eat. Cutting refined sugars and white flour will usually help you more than cutting modest portions of whole fruits and high fiber grains. You will see later how the quality of your carbs can change your risk of type 2 diabetes.
See how low carb affects your blood sugar
When you eat fewer carbohydrates, your body needs to produce less insulin to handle the incoming glucose. This has two main effects if you live with diabetes or prediabetes.
First, your blood sugar spikes tend to be lower, so you spend more time in your target blood glucose range. A 2021 meta analysis published in BMJ found that people with type 2 diabetes who followed a low carbohydrate diet, defined as less than 26 percent of calories from carbs, were more likely to reach an A1C below 6.5 percent or a fasting blood sugar under 126 mg/dL within six months than those on other diets or their usual diet (American Academy of Family Physicians).
Second, your pancreas may get a break from constant high demand for insulin. A trial reported by Harvard Health looked at 150 adults with untreated prediabetes or mild diabetes who cut carbs to below 40 grams per day at first, then below 60 grams. Over six months, participants on the low carb diet had larger drops in A1C and fasting blood sugar than those eating their usual diet, and their improvements suggested nearly a 60 percent lower risk of developing diabetes in the next three years (Harvard Health Publishing).
These changes can start within days or weeks of lowering carbs, which is why you must work closely with your doctor if you take insulin or other medicines that can cause low blood sugar.
Use low carb to lose weight and improve insulin resistance
Carb cutting does not magically melt fat, but it often makes weight loss easier, which in turn can improve your diabetes health quickly.
When you reduce starchy and sugary foods and replace them with lean protein, healthy fats, and non starchy vegetables, you usually feel fuller on fewer calories. In the Harvard trial, people on the low carb diet lost an average of 13 pounds in six months, more than those on their usual diet (Harvard Health Publishing).
Weight loss of around 15 kilograms, or about 33 pounds, within three to five months can significantly boost your chance of putting type 2 diabetes into remission, especially if you lose the weight within six years of diagnosis. A low carb diet is one approach that can help you reach that level of loss (Diabetes UK).
Lower body weight usually means less insulin resistance. Your cells respond better to the insulin you produce, so your blood sugar becomes easier to control, even if your carb intake is not extremely low. Some studies suggest that low carb diets help your blood sugar both through weight loss and by lowering the demand on your pancreas independent of weight loss, which gives you two potential benefits at once (Harvard Health Publishing).
Look at what the long term studies show
You might be most interested in what happens quickly, but it is important to know what research shows over months and years as well.
A 2025 systematic review evaluated adults with type 2 diabetes who followed low carbohydrate or ketogenic diets for one to eight years. Overall, these diets led to significant reductions in A1C, body weight, body mass index, and systolic blood pressure. Many participants were also able to reduce their use of glucose lowering and blood pressure medications (PubMed).
Remission rates of type 2 diabetes were highest at one year, up to 62 percent in some studies, but remission fell to around 13 percent by five years, which suggests that long term success depends heavily on how well you can maintain the diet over time (PubMed).
Other analyses, including eight randomized controlled trials from 2010 to 2015, found that low carb diets improved blood sugar, weight, and heart risk markers in the short term, but they did not consistently outperform higher carb, calorie controlled diets after 12 to 24 months (Diabetes Therapy). This is one reason why major diabetes organizations now recommend a personalized eating pattern that you can live with long term rather than a single strict rule for everyone.
Compare low carb, keto, and Mediterranean styles
Not all low carb diets are the same. You can choose a version that fits your lifestyle and your lab results.
Very low carb or ketogenic diets often cap carbs below 10 percent of your calories and increase fat intake, which can produce rapid changes in blood sugar and weight. Some studies show that people with type 2 diabetes who followed a strict low carb plan for six months maintained good blood sugar control for three years if they kept up the diet (Healthline).
On the other hand, the Mediterranean diet is naturally lower in refined carbs but includes whole grains, fruits, and legumes, along with healthy fats from olive oil, nuts, seeds, and fish. A 2022 Stanford Medicine study compared a ketogenic diet to a Mediterranean diet in people with type 2 diabetes or prediabetes. Both diets lowered A1C and helped with weight loss, with A1C dropping 9 percent on keto and 7 percent on Mediterranean, so blood sugar control was similar (Stanford Medicine).
Participants tended to find the Mediterranean approach easier to stick with, since keto excludes legumes, fruits, and many whole grains. The study also found that LDL cholesterol increased with keto but decreased with the Mediterranean diet, while both improved triglycerides, with a larger triglyceride drop on keto (Stanford Medicine).
If you aim for quick improvements in diabetes health without making your diet so strict that you cannot maintain it, you might start with a moderate low carb or Mediterranean style plan and only move toward very low carb if you and your doctor decide it is appropriate.
Focus on plant based, high quality carbs and fats
How you structure your low carb diet matters as much as how many grams you eat. Research suggests that plant focused, reduced carb patterns may protect you from type 2 diabetes while animal heavy versions can raise your risk.
An analysis of over 203,000 adults followed for up to 30 years looked at people in the lowest carb group, where about 40 percent of daily energy came from carbs. Those who ate more plant based proteins and fats had a 6 percent lower risk of type 2 diabetes. If they also avoided sugar and refined carbs, their risk dropped by 15 percent (American Heart Association News).
By contrast, people in the lowest carb group who focused on animal protein and fat had a 35 percent higher risk of type 2 diabetes. This risk jumped to 39 percent when they also ate very few whole grains (American Heart Association News).
This means your low carb plate should highlight foods like:
- Non starchy vegetables such as leafy greens, broccoli, peppers, and zucchini
- Plant proteins like tofu, tempeh, lentils, and beans in portions that fit your carb target
- Nuts, seeds, and natural nut butters
- Healthy fats from olive oil, avocado, and fatty fish like salmon
You can still include some lean animal proteins if you enjoy them, but try to build your meals around plants first, especially if you are lowering carbs for the long haul.
A low carb diet and diabetes health go hand in hand when you cut refined carbohydrates and added sugars first, then choose mostly plant based proteins and fats to replace them.
Start a low carb diet safely and realistically
If you take insulin or medicines that increase hypoglycemia risk, talk with your doctor or diabetes educator before reducing carbs. Significant carb cuts often require medication adjustments, and some studies report that many participants were able to reduce or stop certain drugs when limiting carbs to around 20 grams per day, but these changes were made under medical supervision (Healthline).
If your care team agrees low carb is a good fit, you can begin with small, specific changes:
- Swap sugary drinks for water, unsweetened tea, or coffee.
- Replace white bread, pasta, and rice with non starchy vegetables and modest portions of whole grains if they fit your plan.
- Build each meal around a protein source, non starchy vegetables, and a source of healthy fat.
- Move snacks away from chips, crackers, and sweets toward nuts, cheese, yogurt without added sugar, or cut vegetables with hummus.
You may notice temporary side effects like constipation or bad breath as your body adapts to fewer carbs. These are usually not harmful long term and tend to improve when you drink enough fluids and focus on high fiber, healthy carb sources instead of simply cutting all carbs quickly (Diabetes UK).
If you have type 1 diabetes, low carb diets are more controversial, and major organizations note that there is not strong evidence for their safety or benefit yet. In that case, carb counting to match your insulin dose to your carb intake is the standard approach, so you should be especially cautious about any major diet shift (Diabetes UK).
Balance quick wins with long term habits
The research is clear that a low carb diet can improve your diabetes health fast. Within weeks or months you may see:
- Lower fasting and post meal blood sugars
- Reduced A1C
- Weight loss and less belly fat
- Better blood pressure and triglyceride levels
- Lower medication needs if your doctor adjusts them appropriately
At the same time, long term studies do not show that low carb diets are always superior to other calorie controlled, high quality eating patterns beyond one to two years (Diabetes Therapy). The best diet for you is one you can follow consistently, that keeps your blood sugar in range, and that fits your preferences and medical needs.
You might start by lowering your carbs enough to see quick improvements and build motivation, then slowly adjust toward a sustainable pattern, such as a mostly Mediterranean style mixed with some low carb structure. Working with your healthcare team can help you fine tune your carb level, choose the right medications, and stay on track without feeling deprived.
Diabetes affects more than 500 million people worldwide, but maintaining good blood sugar, whether through low carb or another evidence based diet, can sharply reduce your risk of complications (Healthline). Your plate is a powerful tool, and even one low carb change at your next meal can move you toward better diabetes health.
