I was diagnosed with Diabetes Type II on March 30, 2015.
There is a whole category at this site devoted to this topic, so there is more to say, there. In my case, I was lucky – early inset meant that diet, alone, is taking a good whack at control. I have always exercised regularly; in fact, I cut out the weight training parts (at least for now).
Within 3.5 months, my numbers all reduced to non-diabetic levels, and my weight returned the 2014 me to the 1984 me (although my 1984 hair did not return), and my dosage on the medication (a well tolerated drug known as metformin) is getting dialed back.
This is the second chronic condition I have developed. The first was in 2005, blood clots derived from one of the known hyper-coagulative mutations (G20210A), which there is a category for here, also.
Age. It is not for the young.
I have not touched on the challenges of travel and living in hotels, which I do quite a bit. As long as I have a small refrigerator and access to at least a convenience store, it has not been a problem. I also carry a small store in my backpack, now (various nuts, protein bars, and low-salt chicken jerky). Those portable packets of tuna, along with the jerky, are perfect travelling protein, when you are not cooking; do not forget the plastic utensils.
My opinion is that what I am recommending involves putting the control on you rather than turning it over to some external thing: your endless computer and phone apps, your fitbit recorder, your Atkins Diet, your Weight-Watcher program, your standing desk. All of these things are great, but why ignore the fundamentally simple idea of looking at the input of food into your body, which is a thing you have total control over. And even if it is not actually controlled, monitoring it to know, if only to you in complete privacy, is worth knowing.
Maintaining and manipulating a detailed spreadsheet is also probably not for everyone, either, but I am figuring that if you are still reading this, you can handle it. Someone other than me can try to develop the way to automate it, but I have a sneaky suspicion that automation leads to externalization of control. In a critical way, I think that having to pound the numbers and think about every detail are actually critical to the psychology of this approach. I also love to cook, and invent and adapt meals. If a person did not like to cook, or had to deal with feeding a family, this would all be much more challenging (not the recording, mind you, but the changes).
I knew calories. I knew labels. I knew portions. I had a good idea of what to avoid. But I did not figure it out until I really had to, and when I put all of the pieces into one place. And (frankly) I was shocked at just how easily a normal trip to the grocery store adds up in an unbalanced way. I think there are entire aisles from the grocery store that I will not eat from any more, even when I move my calorie count up to a weight maintenance level.