Here are Studies specifically on the effects of diets on Diabetes (particularly low carbohydrate diets).

• Laura R Saslow, PhD, et.al. An Online Intervention Comparing a Very Low-Carbohydrate Ketogenic Diet and Lifestyle Recommendations Versus a Plate Method Diet in Overweight Individuals With Type 2 Diabetes: A Randomized Controlled Trial. J Med Internet Res. 2017 Feb; 19(2): e36.
• Guenther Boden. (2005). Effect of a Low-Carbohydrate Diet on Appetite, Blood Glucose Levels, and Insulin Resistance in Obese Patients with Type 2 Diabetes. Ann Intern Med. 2005; 142(6):403-411.
• Mary C. Gannon and Frank Q. Nuttall. Effect of a High-Protein, Low-Carbohydrate Diet on Blood Glucose Control in People With Type 2 Diabetes. Diabetes 2004 Sep; 53(9): 2375-2382.
• Jørgen Vesti, Nielsen, Eva Joensson. Low-carbohydrate diet in type 2 diabetes. Stable improvement of bodyweight and glycemic control during 22 months follow-up. Nutrition & Metabolism, December 2006, 3:22.
• Diabetes Care 2002 Apr; 25(4): 652-657. Effects of Energy-Restricted Diets Containing Increased Protein on Weight Loss, Resting Energy Expenditure, and the Thermic Effect of Feeding in Type 2 Diabetes. N.D. Luscombe, BSC HON1, P.M. Clifton, MD2, M. Noakes, MSC, PHD2, B. Parker, BSC HON1 and G. Wittert, MD.
• JAMA. 1994. Effects of Varying Carbohydrate Content of Diet in Patients With Non—Insulin-Dependent Diabetes Mellitus. Abhimanyu Garg, MBBS, MD; John P. Bantle, MD; Robert R. Henry, MD; et al Ann M. Coulston, RD; Kay A. Griver, RD; Susan K. Raatz, MS, RD; Linda Brinkley, RD; Y-D. Ida Chen, PhD; Scott M. Grundy, MD, PhD; Beverley A. Huet, MS; Gerald M. Reaven, MD.
• Lipids. 2009 Apr;44(4):297-309. Carbohydrate restriction has a more favorable impact on the metabolic syndrome than a low fat diet. Volek JS, Phinney SD, Forsythe CE, Quann EE, Wood RJ, Puglisi MJ, Kraemer WJ, Bibus DM, Fernandez ML, Feinman RD.
• J Clin Invest. 1936 Nov; 15(6): 665–671. The Glycemic Response to Isoglucogenic Quantities of Protein and Carbohydrate. Jerome W. Conn and L. H. Newburgh.
• N Engl J Med 1988; 319:829-834. Comparison of a High-Carbohydrate Diet with a High-Monounsaturated-Fat Diet in Patients with Non-Insulin-Dependent Diabetes Mellitus. Abhimanyu Garg, M.B., B.S., M.D., Andrea Bonanome, M.D., Scott M. Grundy, M.D., Ph.D., Zu-Jun Zhang, M.D., and Roger H. Unger, M.D.
• Metabolism. Volume 41, Issue 12, December 1992, Pages 1373-1378 Metabolism. A high-monounsaturated-fat/low-carbohydrate diet improves peripheral insulin sensitivity in non-insulin-dependent diabetic patients. M. Parillo, A.A. Rivellese, A.V. Ciardullo, B. Capaldo, A. Giacco, S. Genovese, G. Riccardi.
• The Journal of Clinical Endocrinology & Metabolism, Volume 86, Issue 3, 1 March 2001, Pages 1040–1047, Effect of Protein Ingestion on the Glucose Appearance Rate in People with Type 2 Diabetes. M. C. Gannon J. A. Nuttall G. Damberg V. Gupta F. Q. Nuttall.
• Obesity (2016) 24, 79–86. Weight Loss on Low-Fat vs. Low-Carbohydrate Diets by Insulin Resistance Status Among Overweight Adults and Adults With Obesity: A Randomized Pilot Trial. Christopher D. Gardner, Lisa C. Offringa, Jennifer C. Hartle, Kris Kapphahn, and Rise Cherin.
• Bonnie J. Brehm, Randy J. Seeley, Stephen R. Daniels, David A. D’Alessio. A Randomized Trial Comparing a Very Low Carbohydrate Diet and a Calorie-Restricted Low Fat Diet on Body Weight and Cardiovascular Risk Factors in Healthy Women. The Journal of Clinical Endocrinology & Metabolism, Volume 88, Issue 4, 1 April 2003, Pages 1617–1623.
• Nutr Metab (Lond). 2006 Jan 11;3:7. Comparison of isocaloric very low carbohydrate/high saturated fat and high carbohydrate/low saturated fat diets on body composition and cardiovascular risk. Noakes M, Foster PR, Keogh JB, James AP, Mamo JC, Clifton PM.
• Jeannie Tay B Nutr Diet (Hons), Grant D. Brinkworth PhD, Manny Noakes PhD, Jennifer Keogh M Sc, Peter M. Clifton PhD. Metabolic Effects of Weight Loss on a Very-Low-Carbohydrate Diet Compared With an Isocaloric High-Carbohydrate Diet in Abdominally Obese Subjects. Journal of the American College of Cardiology, Volume 51, Issue 1, 1–8 January 2008, Pages 59-67.
• JAMA. 1994 May 11;271(18):1421-8. Effects of varying carbohydrate content of diet in patients with non-insulin-dependent diabetes mellitus. Garg A, Bantle JP, Henry RR, Coulston AM, Griver KA, Raatz SK, Brinkley L, Chen YD, Grundy SM, Huet BA, et al.
• Nutrition & Metabolism2004 1:6. Metabolic response of people with type 2 diabetes to a high protein diet. Frank Q Nuttall, Mary C Gannon.
• Obes Facts. 2017 Jul; 10(3): 238–251. Effect of a High-Protein Diet versus Standard-Protein Diet on Weight Loss and Biomarkers of Metabolic Syndrome: A Randomized Clinical Trial. Ismael Campos-Nonato, Lucia Hernandez, and Simon Barquera.
• J Clin Invest. 1988 Feb; 81(2): 442–448. Twenty-four-hour profiles and pulsatile patterns of insulin secretion in normal and obese subjects. K S Polonsky, B D Given, and E Van Cauter.
• Nutrients. 2013 Jun; 5(6): 2019–2027. Body Fat Distribution and Insulin Resistance. Pavankumar Patel* and Nicola Abate.
• Connor WE, Prince MJ, Ullmann D, et al. The hypotriglyceridemic effect of fish oil in adult-onset diabetes without adverse glucose control. Ann N Y Acad Sci 1993;683:337–40.
• Fish Oil and Glycemic Control in Diabetes. DIABETES CARE, VOLUME 21, NUMBER 4, APRIL 1998. Frieberg, et.al.).
• Insulin Response to Glucose in Diabetic and Nondiabetic Subjects. John D. Bagdade, Edwin L. Bierman, and Daniel Porte Jr. Journal of Clinical Investigation. October 1, 1967.