Type 2 Diabetes & Glycemic Control
What does research show about a ketogenic or low-carb diet for type 2 diabetes?
Copper Keto Companion gathers the type 2 diabetes research here — the remission and HbA1c meta-analyses and the longer randomized trials — including the studies where the early glycemic advantage faded by 12 months and the ones funded by the intervention's maker.
Contents — 6 entries
- 📄 Low-Carb Diets and Type 2 Diabetes Remission (Meta-Analysis)
- 📄 Carbohydrate Restriction and HbA1c in Type 2 Diabetes (Meta-Analysis)
- 📄 Ketogenic Continuous-Care Model at 1 Year (Non-Randomized)
- 📄 Ketogenic Continuous-Care Model at 2 Years (Non-Randomized)
- 📄 Low- vs High-Carbohydrate Diet for Type 2 Diabetes (52-Week RCT)
- 📄 Low-Carb vs Low-Fat Advice in Type 2 Diabetes (2-Year RCT)
📄 Low-Carb Diets and Type 2 Diabetes Remission (Meta-Analysis)
Goldenberg JZ, et al. — BMJ, 2021 · pubmed / 33441384
Copper Keto Companion research surfaced this report because it covers low-carbohydrate diets and diabetes remission. Pooling 23 randomized trials and 1,357 participants, the 2021 meta-analysis found that at 6 months low-carb diets reached higher diabetes remission than control diets (57% versus 31%, with remission defined as HbA1c below 6.5%; risk difference 0.32, 95% CI 0.17 to 0.47, from 8 studies with 264 people). The large improvements in weight, triglycerides, and insulin sensitivity seen at 6 months diminished by 12 months, and the 12-month remission data were sparse and low-certainty.
What it examines: a meta-analysis of low-carbohydrate diets and type 2 diabetes remission at 6 and 12 months. Why it's in the Copper Keto Companion research index: a pooled analysis of low-carb trials and diabetes remission over time.
📄 Carbohydrate Restriction and HbA1c in Type 2 Diabetes (Meta-Analysis)
Snorgaard O, et al. — BMJ Open Diabetes Research & Care, 2017 · pubmed / 28316796
Copper Keto Companion research surfaced this report because it covers how much carbohydrate restriction changes blood sugar over time. Combining 10 randomized trials and 1,376 people with type 2 diabetes, the 2017 meta-analysis found a low-carbohydrate diet lowered HbA1c by 0.34% (3.7 mmol/mol) more than a high-carbohydrate diet in the first year, with a larger effect at greater carbohydrate restriction. At 1 year or later, HbA1c was similar in the two diet groups, so the advantage did not persist.
What it examines: a meta-analysis of carbohydrate restriction and HbA1c in type 2 diabetes. Why it's in the Copper Keto Companion research index: a pooled analysis of carbohydrate restriction and blood-sugar control over time.
📄 Ketogenic Continuous-Care Model at 1 Year (Non-Randomized)
Hallberg SJ, et al. — Diabetes Therapy, 2018 · pubmed / 29417495
Copper Keto Companion research surfaced this report because it covers a ketogenic care program for type 2 diabetes. In a 1-year open-label, non-randomized study of 262 people in the intervention and 87 in usual care, HbA1c fell from 7.6% to 6.3% and insulin therapy was reduced or eliminated in 94% of the people using it. The study was funded by the company providing the intervention (Virta Health) and was not randomized, so participants chose their group and motivation may differ between the groups.
What it examines: a 1-year non-randomized study of a ketogenic continuous-care model on HbA1c and medication. Why it's in the Copper Keto Companion research index: a non-randomized trial of a ketogenic care program and diabetes medication use.
📄 Ketogenic Continuous-Care Model at 2 Years (Non-Randomized)
Athinarayanan SJ, et al. — Frontiers in Endocrinology, 2019 · pubmed / 31231311
Copper Keto Companion research surfaced this report because it covers the 2-year results of a ketogenic diabetes care program. In the same non-randomized cohort of 262 intervention participants and 87 usual-care controls, use of glycemic medication other than metformin fell from 55.7% to 26.8% (insulin down 62%, sulfonylureas down 100%), and diabetes was recorded as reversed in 53.5% and in remission in 17.6% of the intervention group but not usual care. The study was industry-funded (Virta Health) and non-randomized, and some measures regressed from the 1-year results alongside 2-year dropout.
What it examines: a 2-year non-randomized study of a ketogenic care model on medication use and diabetes status. Why it's in the Copper Keto Companion research index: a non-randomized 2-year trial of a ketogenic care program and diabetes status.
📄 Low- vs High-Carbohydrate Diet for Type 2 Diabetes (52-Week RCT)
Tay J, et al. — American Journal of Clinical Nutrition, 2015 · pubmed / 26224300
Copper Keto Companion research surfaced this report because it covers a year-long randomized comparison of low- versus high-carbohydrate eating in type 2 diabetes. Among 115 adults over 52 weeks with matched calories and exercise, the low- and high-carb groups had similar weight loss (9.8 versus 10.1 kg) and the same HbA1c reduction (both 1.0%), while the low-carb group had larger reductions in diabetes-medication score, blood-sugar variability, and triglycerides and a larger HDL rise. On the main outcomes the low-carb diet was not better; its advantages were in the secondary medication and lipid measures.
What it examines: a 52-week randomized trial of low- versus high-carbohydrate diets in type 2 diabetes. Why it's in the Copper Keto Companion research index: a year-long randomized comparison of carbohydrate levels in diabetes.
📄 Low-Carb vs Low-Fat Advice in Type 2 Diabetes (2-Year RCT)
Guldbrand H, et al. — Diabetologia, 2012 · pubmed / 22562179
Copper Keto Companion research surfaced this report because it covers whether a low-carb advantage in diabetes lasts. In a 2-year randomized trial of 61 people given advice to follow a low-carbohydrate or low-fat diet with similar weight loss, HbA1c improved more on low-carb at 6 months (a fall of 4.8 mmol/mol, P = 0.004) but the difference was no longer significant at 12 months (2.2 mmol/mol, P = 0.12). The trial was small and advice-based rather than supervised feeding, and the glycemic benefit was transient.
What it examines: a 2-year randomized trial of low-carb versus low-fat dietary advice in type 2 diabetes. Why it's in the Copper Keto Companion research index: a randomized trial of the durability of a low-carb glycemic advantage.
All 6 sources last verified September 2026.
Frequently Asked Questions
Can a keto or low-carb diet reverse type 2 diabetes?
Some studies report high remission at 6 months — one meta-analysis found 57% versus 31% on control diets (Goldenberg, 2021) — but the effect diminished by 12 months, and the biggest remission numbers come from a non-randomized, industry-funded program (Athinarayanan, 2019). This summarizes research and is not medical advice; talk to your doctor before changing a diabetes diet or medication.
Does low-carb lower HbA1c in type 2 diabetes?
In the first 6 to 12 months, modestly: a meta-analysis found HbA1c about 0.34% lower than high-carb (Snorgaard, 2017). By one year the difference faded, and a 52-week randomized trial found the same HbA1c drop on low- and high-carb diets (Tay, 2015).
Do the benefits last?
Often not on their own. Glycemic improvements at 6 months diminished by 12 months across trials (Goldenberg, 2021), and a 2-year trial found the low-carb HbA1c advantage was significant at 6 months but not at 12 (Guldbrand, 2012).
Are the diabetes-remission studies reliable?
The largest single-program results (Virta) are non-randomized and industry-funded, with participants choosing their group (Hallberg, 2018; Athinarayanan, 2019), while the randomized trials show smaller, less durable effects (Tay, 2015; Guldbrand, 2012). This is not medical advice.
More in Keto Research
Educational information only — not medical advice, and not a recommendation to start, stop, or change any diet, supplement, or treatment. Talk to a qualified healthcare professional before making changes. Copper Keto Companion and Copper Sun Content and Creative, LLC are not medical providers.