You sound like such a loving daughter-in-law, and that alone will make a great difference in your father-in-law's health.
Here is an invaluable link that will give you information that it appears nobody else who has yet replied has been able to provide: http://www.westonaprice.org/moderndiseases/diabetes.html
The article at this URL is "Treating Diabetes: Practical Advice for Combatting a Modern Epidemic" By Tom Cowan, MD. Dr. Cowan is a physician in private practice in San Francisco, California. He is the author of The Fourfold Path to Healing. His website is http://www.fourfoldhealing.com.
Diabetes is linked with heart disease, as your father-in-law has experienced. What you serve for dinner can make a big difference in your father-in-law's health and longevity, but he may have been advised by conventional medical practitioners not to eat the foods that I believe are most likely to help him. This is a good time to look into self-education.
According to Dr. Cowan and the Nutritional Therapy Association, under which I received nutritional therapy training, the main cause of diabetes is the western diet:
->refined carbohydrates like sugar and white flour, that rush sugar into the bloodstream
->trans fatty acids that interfere with insulin receptors in the cells
->improperly prepared foods that are difficult to digest such as pasteurized milk, unfermented soy products, uncooked vegetables, nuts, and grains
->mineral deficiencies from an agricultural system that depletes its soils
->toxins such as pesticides and heavy metals from environmental exposures and on and in foods
Before insulin was available, the only way to treat type I diabetes was a high-fat diet from which carbohydrate foods were completely excluded because the body does not need insulin to assimilate proteins and fats. Today, this is also a great approach, if the high-fat diet is composed of healthy fats.
Most people think of Omega 3's and olive oil when I use the term "healthy fats," but what I mean are naturally occurring, unprocessed fats, such as the fat on grassfed meats, in eggs from pastured poultry, in full-fat raw or cultured dairy from pastured animals, and organic, cold-pressed coconut or palm oils. High-vitamin cod liver oil and butter oil are also very healthy fats.
Diabetes is often accompanied by mineral deficiency, particularly deficiencies in zinc, vanadium and chromium. Good foods for trace minerals are bone broths, beet kvass, shellfish (esp. oysters, don't buy farmed seafood), unfiltered extra virgin olive oil (make sure it's not fake, since some of the major brands are selling vegetable oil mixed in with the olive oil), unrefined sea salt, molasses, and liver.
Iodine is also a critical trace mineral for diabetics. Iodoral is a great supplement, if your father-in-law is interested, but it's important to take iodine with tiny amounts of Rubidium, which I get as a supplement from Biotics. A person who uses fish bones to make bone broth and eats that every day with seaweed, will most likely get plenty of iodine and rubidium, no need for supplements.
Diabetes often involves a deficiency in Vitamin B6, which is essential for carbohydrate metabolism. B6 is derived from raw animal foods. Sushi with raw fish, proscuitto, raw milk, and rare roasted lamb or pastured beef are all rich in B6, one of the most commonly deficient vitamins. (The deficiency also leads to carpal tunnel syndrome and more.)
Diabetics need foods rich in fat-soluble vitamins, including butterfat from grass-fed animals, organ meats, shellfish, fish liver oils, tallow and lard from pastured livestock.
Beta-carotenes (such as in carrots) don't work for diabetics. They need high levels of vitamin A - retinol - because diabetics are unable to convert the carotenes in plant foods into true vitamin A. Your father-in-law might want to take a daily dose of high-vitamin cod liver oil to provide at least 20,000 IU vitamin A per day. Cod liver oil is also an ideal food supplement for pregnant mothers, nursing mothers, and growing children.
A dose of cod liver oil that provides 20,000 IU vitamin A will provide 2,000 IU vitamin D. Vitamin D is necessary for the production of insulin. Find Vitamin D in yellow butter and orange egg yolks from pastured animals, lard and bacon from pastured pigs raised outdoors in the sunlight, and high-vitamin butter oil.
Diabetics must carefully limit carbohydrate intake. This was probably the cause of the problem in the first place. I don't mean it's your father-in-law's fault that he is sick because he ate the wrong foods. He most likely did what everybody else is doing and what we are told to do.
We are told by the FDA food pyramid to base our diet on carbohydrates, with very little distinction between nutrient dense, properly prepared carbohydrates and toxic, indigestible, nutrient-free processed foods. We are told to avoid the foods with the natural fats that will keep us healthy.
Carcinogenic processed vegetables and trans fats are only just now getting any coverage about how toxic they are, and notice there really isn't much mentioned about industrially processed margarine and vegetable oils, which I believe are deadly. Those who make an effort to eat truly healthy foods in the US today know that it's not that easy.
Glycemic index isn't very important if a person is eating enough fats, because the fats will slow sugar absorption down enough so that it doesn't make a difference what the glycemic index is. It's much more important that carbohydrates are avoided, and any that are eaten are properly prepared and nutrient dense.
See Sally Fallon's cookbook, Nourishing Traditions, for good recipe ideas. Just about anything in that cookbook will be good for your father-in-law, as a matter of fact. Another fantastic cookbook that is very read-able is "Full Moon Feast" by Jessica Prentiss.
Good luck and you are so precious to be so concerned for your father-in-law's health. If you take advantage of this opportunity to learn more about diabetes and a healthy diet, what you learn through your care for him may be something that can prevent this type of chronic disease in other family members. I'm sure he would want that for you all.
M. Minno