Is taking insulin as a type one diabetic causing my weight gain? even though i'm on a calorie deficit and exercise daily? i keep hearing that insulin spikes cause weight gain but i don't know if that applies to type one diabetics?

Insulin is just a carrier protein, acting like a taxi to carry glucose into the cells. It will transfer all the glucose you consume in whatever form and all excesses will make you gain weight. Too much insulin at one time can drop your blood sugar to the point you are hungry & want to eat, but that is a management issue. Don't blame the insulin, it's how you use it and what you eat Type 1 or 2.

In addition to the information provided by Dr. Ferguson, please note that insulin also acts as a growth factor and does promote weight gain. It would be prudent to discuss all this with your doctor who knows more about your health. For technical information: https://pubmed.ncbi.nlm.nih.gov/32208563/