As a type1 diabetic myself, I hope I can help
I'm quite skinny but have always had a bit of a gut even though I'm very active (weekly Sunday league midfielder, 1x hiit session a week, twice a week gym, daily 30 min dog walks and children
The things that I changed and saw making a difference were
Changing from doing big weight deadlifting and squatting into doing high intensity kettlebell circuits
Doing 2 times hiit sessions on pelaton or sprints on football pitch
Inclusion of 1 x core workout
Croissants and crisps are my guilty please - so cutting these down
Cutting down beer
Eating more vegetable orientated meals, less meat meals in the week. Focusing day time snacks around fruit and nuts( sounds boring but is actually nice once you get into it)
I was also on insulin injections and was moved over to insulin pod therapy, though there was a frustrating 6 month period of adjusting, the better sugar levels now are benefiting me with more energy and possibly reducing the fat on me
The workouts I've mentioned above I try to keep within 20-30 mins so I make the most of the time and go hard in that time
Happy to discuss further if you wanted to ask qs or dm me
Good luck!