Can Diabetics Fast?
Question

I have diabetes type II which is NIDM non-insulin dependent diabetes, I don't use any medicine, I only control diet and I do little physical exercise to keep in right level of my sugar(blood).
I have had this disease for one year and two months. Last Ramadan I fasted some days but I could not continue due to my low level of sugar(blood). This year I feel good (Alhamdu Lillah) I ONLY feel pain in my brain during fasting!? So my question is, is it my DUTY to fast despite my disease? Can I test my blood during fasting times; "causing blood to come from my fingers"?
Praise be to Allah.Can sick people break the fast?
It is prescribed for sick people not to fast in Ramadan, if fasting will cause harm or make the sickness worse, or if they need treatment during the day in the form of medicine or pills that must be swallowed. Allah says (interpretation of the meaning): 
“and whoever is ill or on a journey, the same number [of days which one did not observe Sawm (fasts) must be made up] from other days” [al-Baqarah 2:185]
Prophet Muhammad (peace and blessings of Allah be upon him) said: “Allah loves people to avail themselves of His concessions (rukhsah) just as He hates them to commit sin.” According to another version, “As He loves His commands to be obeyed.” 
Can we check sugar during fasting?
With regard to taking blood from veins for testing etc., the correct view is that this does not break the fast, but if it is done often, it is better to leave it until night-time. If it is done during the day then to be on the safe side that day should be made up, because this is akin to cupping.” (Fatwa of Shaykh Ibn Baz (may Allah have mercy on him), from Fatawa Islamiyyah, vol. 2, p. 139) 
Can diabetics fast?
Sickness is of various kinds: 

That which does not affect the fast, such as a light cold or mild headache or toothache, and the like. In this case it is not permissible to break the fast, even though some of the scholars permitted that because of the ayah (interpretation of the meaning): “and whoever is ill…”[al-Baqarah 2:185]

But we say that this ruling is based on a reason, which is that not fasting is easier. If that is the case, then we would say that not fasting is better, but if fasting does not have an effect on him then it is not permissible to break the fast, and he has to fast. 

If fasting is difficult for the sick person, but it does not harm him, then it is makruh for him to fast and it is Sunnah for him to break his fast. 
If fasting is difficult for him and will cause him harm , such as a man who has kidney disease or diabetes and similar cases where fasting will cause harm. In this case fasting is haram. Hence we may see that some mujtahids and sick people make a mistake when fasting is difficult for them and may harm them, but they refuse to break their fast. We say that they are mistaken because they refuse to accept the kindness of Allah and the concession that He has given to them, and they are harming themselves, although Allah says (interpretation of the meaning): “And do not kill yourselves”[al-Nisa 4:29] (Al-Sharh al-Mumti’ by Shaykh Ibn ‘Uthaymin, vol. 6, 352-254)

And Allah knows best.