51 years on insulin.
The short answer is that weight gain and weight loss is 75% about diet and 25% about exercise. To add to that. if the insulin dose is too high, the diet calories increase, or the insulin is more efficient with your present diet, either way your weight increases.
The longer answer is about the following:
My impression ( and this post is not medical advice or opinion) of being on insulin over 51 years of TID is that the earlier you are in your journey, once past the turbulent teenage years of growth, the more tolerable one's blood sugar is to insulin, and the longer on insulin injections the more difficult blood sugar control by insulin injections is. Of course like all generalisations there will be exceptions.
So a flat 24 hour + acting insulin like Tresiba cannot totally fulfill my basal insulin needs. My pump basal settings prove it. yes, i would need to trial Tresiba to absolutely prove it but I was aware of the deficiencies of Levemir twice daily ( for 14 years) vs my insulin pump workings and settings some 6 years ago.
So my basal settings (Novorapid in IU) : 12 mn - 0.475, 3 am 0.750, 4 am .950, 5am 1.125, 6 am .925, 7 am .60, 10 am 0.50, 3 0.425, 6 pm 0.925. 9.30 pm 0.425. The only really flat infusion rates are 12mn to 3 am, 10am to 3 pm and 9.30 pm to12 mn.
= < 12 hours per 24 hour day.
So to 'cover' such variations with something like Tresiba , the dose might be set to cover the peaks with the risk of hypos in between or set lower to prevent hypos but risk higher than desirable readings.
Maybe insulins like Levenmir twice daily or Lantus once daily do not cover the 24 hours and blood sugars goes up and ketones appear which on Tresiba is 'fixed' but with increased uptake of blood sugar into cells,. including fat cells. = weight gain.
I hope that explains what might be happening. Of course checking with your DN and doctor is the best way forward to solve this.
