Protein
The appropriate level of protein intake for diabetic patients is unclear. The ADA's official assessment is that there is no ideal intake to improve glycemic control or CVD risk. Some experts propose a high protein diet with an emphasis on plant-based, high-quality proteins. Others argue for a focus on fiber, fruit, vegetables, and whole grains.
Regardless, it is clear that consideration of the protein source is an important factor. So when choosing protein-rich foods, pay attention to what comes along with the protein! Fat and carbohydrate intake is often related to protein source with direct implications on diabetes and other health conditions.
Regarding specific protein sources:
Eggs
Data was used from 2 completed randomized studies: the Physicians' Health Study I (20,703 men) and the Women's Health Study (36,295 women). Egg consumption was ascertained using questionnaires, and the relative risks of type 2 diabetes were estimated. These data suggest that high levels of egg consumption (daily) are associated with an increased risk of type 2 diabetes in men and women (1). Consumption of at least 7 eggs per week when compared with no egg consumption yielded multivariable adjusted hazard ratios for type 2 diabetes of 1.58 for men and 1.77 for women.
Pulses
Lentils, peas, chickpeas and beans are good vegan protein sources. A systematic review and meta-analysis of RCTs demonstrated that pulses, alone or in low-GI or high-fibre diets, improve markers of longer term glycaemic control (2).
1. Djousse, L., J. M. Gaziano, J. E. Buring, and I-M. Lee. "Egg Consumption and Risk of Type 2 Diabetes in Men and Women." Diabetes Care 32.2 (2008): 295-300.
2. Sievenpiper JL, Kendall CW, Esfahani A, Wong JM, Carleton AJ, Jiang HY, Bazinet RP, Vidgen E, Jenkins DJ. Effect of non-oil-seed pulses on glycaemic control: a systematic review and meta-analysis of randomised controlled experimental trials in people with and without diabetes. Diabetologia. 2009. Aug;52(8):1479-95.