When you first start insulin it's common to gain weight. But it's because all that food you eat is now being utilized. Before insulin you were peeing out a good amount of the calories you ate. If you are dropping later as
@Antje77 has said, it's too big of a dose for what you ate, then you eat more because you have dropped too much.............another way to add to weight gain because you are eating more food.
I know I gained weight when I first started insulin too and they said don't worry about it, yea right, they don't have to be the ones to try to lose it later.
If sugars are going up too much from what you ate, for me it's a matter of the timing of my insulin. It's not a matter of increasing insulin or you end up dropping too much later. I prebolus half of what I think I will need 20-30 minutes before I eat. That way I can adjust the second dose to what I actually felt like eating. Some people only need to prebolus 10 minutes before and if it's higher fat maybe when you eat. You have to learn what works for you because we can all vary. Fiasp is quicker than what mostly I use, so you will have to learn your timing.
But the important thing to remember is you take insulin for what you eat, not end up eating for what you take. Too much food, then too much insulin and you gain weight. I also noticed you might have a thyroid issue? That just adds to the problem of easy weight gain. While one person can eat 3 full meals a day, another person blinks and gains weight. It's unfair but it is what it is.
I just want to add. I have DP (dawn phenomenon) which is an increase in BG level before you wake to get ready for the day or FOTF (foot on the floor) which is a BG increase right after you wake. And because of the hormone releases that cause it, it also makes you insulin resistant for a few hours after. I have a problem eating in the AM because of that and I overreact to food and it's way too hard to dose right for it, so I skip eating until noon.
