There's a long history of studies showing Low-Calorie Diets as being effective for reversing T2D. The late Sarah Hallberg wrote a narrative review that I liked a lot a couple years back (see section 3.2 for the part on LCDs): https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6520897/
Hallberg SJ, Gershuni VM, Hazbun TL, Athinarayanan SJ. Reversing Type 2 Diabetes: A Narrative Review of the Evidence. Nutrients. 2019 Apr 1;11(4):766. doi: 10.3390/nu11040766. PMID: 30939855; PMCID: PMC6520897.
Hallberg SJ, Gershuni VM, Hazbun TL, Athinarayanan SJ. Reversing Type 2 Diabetes: A Narrative Review of the Evidence. Nutrients. 2019 Apr 1;11(4):766. doi: 10.3390/nu11040766. PMID: 30939855; PMCID: PMC6520897.