I have had Type 1 for nearly 30 years and my diet has changed a lot over the years. I have never been fat but I am short and am a little muscular/stocky due to my body shape. I dont think I noticed weight gain initially although I did gain all the weight I lost back after diagnosis.
I am just reading Dr Bernstein's book the diabetes solution, he promotes a very strict diet with very low carb intake mainly from vegetables (some), he is in his 80's now and doing very well. He talks about the role of insulin, how it promotes fat storage etc which is good to know, I have not quite got my head around it yet, I have the book on kindle so cant flick back and forth through the pages and will buy the book to help me better understand the health impact. His diet depresses me a little in that it is just protein and limited amounts of veg - I don't eat meat so it would be very restrictive for me, he also eats processed foods using sweeteners which I don't like.
I will read the book but at the moment I am thinking about compromising, I already limit my carb intake, my diet is high is all veg, I eat some fruit everyday and I use pineapple juice or a Nakd bar if I need to raise my glucose between meals. I ensure I have some protein with each meal if possible and use healthy fats.
For me currently, I am focussing on health and nutrients first (from lots of veg, some fruit, limited starchy foods and good fats and protein) rather than maintaining a steady glucose level, I also drink lots of water and I decide for each meal how much insulin I think I require so it is a guessing game for me and I can be wrong. My body's needs change also and I don't know when this is going to happen, sometimes I need more insulin over a period of time, I know now that when the weather is hotter, I need less NPH insulin (night time insulin) but my fast acting insulin needs remain the same. I am as yet reluctant to follow dr. Bernsteins diet completely as you cant even have tomatoes or balsamic vinegar but I may look to reduce my starchy carb intake more.
I dont take a lot of insulin, between 4 and 7 or 8 units per meal depending on what I am doing and eating and I take about 12 units of NPH each night currently although this can at times in warm weather go down to 8 units or go up to 14-16 units in cold weather (I used to take 20-22 units a night but ate more carb then).
You will learn as you go as I continue to, it is hard trying to balance it all which is why Dr Bernstein's book really appeals to me because his diet seems to give a perfect level of glucose plus on that diet people don't tend to have the severe symptoms of hypoglycaemia even when very low which I have experienced a few times - those symptoms seems to come with carb intake.
Good luck with it all, Ali