And a couple low-sugar recipes: https://www.nutriliving.com/recipes/diabetes-friendly-blast
(omit the greens he cannot have)
You could omit the kale from this recipe and maybe add in some cooked sweet potato: https://www.nutriliving.com/recipes/sippin-sweet-low-carb-treat
Foods rich in Vitamin C, Vitamin E, magnesium, calcium, potassium, monounsaturated fats and omega 3 fatty acids help lower blood pressure.
Foods to eat include all leafy greens like kale, spinach, romaine and chard, beets, broccoli, asparagus, cabbage, celery, crimini mushrooms, onions, garlic, almonds, avocado, walnuts
rice bran (rich in magnesium and many B vitamins), strawberries, kiwi, tomatoes, papaya, raspberries, oranges, bell peppers, potatoes
In addition, foods with a diuretic effect (cucumber, lemon, celery, beets, cabbage, parsley, tomato, watermelon, asparagus) have been shown to help. https://www.nutriliving.com/blog/nutriliving-user-question-diuretic-foods
Please be sure to check in w/ his Dr. to make sure these foods are appropriate for his specific health needs. These are general suggestions based on what you've told me.
Here are some suggestions for blood sugar control: