There is no single “best” diet for people with diabetes who want to lose weight. The American Diabetes Association’s 2024 guidelines are clear on this: any eating pattern that creates a calorie deficit can work, regardless of how you split up carbs, fats, and protein. What matters most is finding an approach you can stick with long enough to lose at least 5% of your body weight, the threshold where blood sugar control starts to meaningfully improve. Lose 10% or more, and the odds of putting type 2 diabetes into remission rise significantly.
Why 5% and 10% Matter So Much
The ADA recommends that people with type 2 diabetes and excess weight aim for at least 5% body weight loss through a combination of diet, physical activity, and behavioral changes. At that level, blood sugar, blood pressure, and cholesterol all tend to improve. For someone weighing 200 pounds, that’s 10 pounds.
But the real milestone is 10%. A community-based study tracking people after their diabetes diagnosis found that those who lost 10% or more of their body weight in the first year were nearly twice as likely to achieve diabetes remission. Over the following one to five years, hitting that 10% mark was associated with a 2.4 times higher chance of remission compared to people whose weight stayed the same. The takeaway: any diet that gets you to 10% weight loss and keeps you there is a strong candidate.
Mediterranean Diet
The Mediterranean pattern, built around vegetables, fruits, whole grains, legumes, nuts, olive oil, and fish, is one of the most studied approaches for diabetes. Multiple large analyses have found it lowers HbA1c (a three-month average of blood sugar) by about 0.3 to 0.5 percentage points compared to low-fat diets. That may sound small, but it’s clinically meaningful, roughly equivalent to adding a mild blood sugar medication.
Beyond blood sugar, this pattern consistently improves cardiovascular risk factors, which matters because heart disease is the leading cause of death in people with type 2 diabetes. The emphasis on healthy fats from olive oil and nuts also makes it more satisfying than traditional low-fat approaches, which can help with long-term adherence.
Low-Carb and Ketogenic Diets
Cutting carbohydrates is one of the most direct ways to lower blood sugar after meals, and the research reflects that. In a 24-week trial comparing a ketogenic diet (under 20 grams of carbs per day) with a low-glycemic-index diet, the ketogenic group lost an average of 11.1 kg (about 24 pounds) compared to 6.9 kg (about 15 pounds) in the other group. HbA1c dropped by 1.5 percentage points on the ketogenic diet versus 0.5 points on the comparison diet.
What’s notable is that the low-glycemic group actually reported eating fewer calories, yet lost less weight. The researchers found that the blood sugar benefits of the ketogenic diet held even after adjusting for the extra weight loss, suggesting that carbohydrate restriction itself plays a role beyond just calorie reduction. The ketogenic group was also more likely to reduce or eliminate diabetes medications during the study.
The catch is sustainability. Very low-carb diets can be difficult to maintain for months or years. A moderate low-carb approach, around 50 to 130 grams of carbohydrates per day, may offer a middle ground that’s easier to live with while still delivering meaningful blood sugar improvements.
Plant-Based Diets
A 74-week clinical trial compared a low-fat vegan diet with a conventional diabetes diet and found both produced sustained weight loss. The vegan group lost an average of 4.4 kg (about 10 pounds) and the conventional group lost 3.0 kg (about 7 pounds), though the difference wasn’t statistically significant. Both groups saw improvements in cholesterol.
Plant-based diets appear to improve insulin sensitivity through a specific mechanism: they reduce fat stored inside muscle cells, which is strongly linked to how well your body responds to insulin. One study found that vegans had 31% less fat in their leg muscles compared to omnivores of the same age and weight. If you prefer eating mostly or entirely from plants, this approach can work well for diabetes and weight loss, particularly when you focus on whole foods rather than processed vegan alternatives.
Intermittent Fasting
Intermittent fasting has gained popularity, and a randomized trial in people with insulin-treated type 2 diabetes showed it can be done safely. Participants fasted three nonconsecutive days per week for 12 weeks, eating only 25% of their normal calories on fasting days (limited to breakfast or lunch). The fasting group lost an average of 4.77 kg (about 10.5 pounds) and reduced their total daily insulin dose by about 9 units. Their HbA1c also improved significantly compared to the control group, and no episodes of severe low blood sugar occurred.
The key safety measure was reducing insulin doses on fasting days and using continuous glucose monitors. If you take insulin or medications that can cause low blood sugar, fasting requires careful coordination with your healthcare team. It’s not something to experiment with on your own.
Fiber and Protein: Two Nutrients Worth Prioritizing
Regardless of which eating pattern you choose, two nutrients deserve extra attention. Fiber slows digestion, keeps you full longer, and blunts blood sugar spikes after meals. The dietary guidelines recommend 22 to 34 grams per day depending on age and sex, but most people fall well short of that. Good sources include beans, lentils, vegetables, whole grains, and berries.
Protein becomes especially important during weight loss because calorie restriction tends to break down muscle along with fat. The standard recommendation of 0.8 grams of protein per kilogram of body weight per day isn’t enough to protect muscle mass in middle-aged and older adults with type 2 diabetes. Research suggests aiming for 1.2 to 1.5 grams per kilogram. For a 180-pound person (about 82 kg), that’s roughly 98 to 123 grams of protein per day, spread across meals.
How Weight Loss Affects Your Medications
One of the most encouraging effects of losing weight with diabetes is that your medication needs often go down. A retrospective study found that for every 5% of body weight lost, doses of insulin dropped by an average of 42%, and doses of certain oral medications dropped by 39%. Most people who achieved dose reductions did so with just 4 to 7% weight loss.
Interestingly, metformin was the one medication that nobody in the study reduced or discontinued, likely because it works through different pathways and remains beneficial regardless of weight. Medications that directly stimulate insulin release or supplemental insulin itself carry a risk of low blood sugar as you lose weight, so these are the ones most likely to need adjustment. This is why regular check-ins with your doctor matter during active weight loss, particularly if you’re on insulin.
Choosing the Right Approach for You
The ADA deliberately avoids naming one best diet because the evidence shows that multiple approaches work when they create a calorie deficit and you can maintain them. Mediterranean, low-carb, plant-based, and intermittent fasting all have solid data supporting their use in diabetes. The differences in blood sugar improvement between them are real but relatively modest compared to the benefit of simply losing weight in the first place.
Start by thinking about what you actually enjoy eating and what fits your daily life. If you love bread and pasta, a strict ketogenic diet will likely fail within weeks. If you dislike cooking elaborate meals, a simple time-restricted eating window might suit you better. The pattern you can follow for a year matters more than the one that looks best in a 12-week study. Pair whichever approach you choose with adequate protein, plenty of fiber, and regular physical activity to protect your muscle mass and maximize the blood sugar benefits of every pound you lose.