Since being diagnosed with T1.5 over 2-years ago I've tried numerous techniques to control both weight and BG.
Looking at both end points as equally important. The most successful was when I was on a consistent carbohydrate / low fat diet with short high intensity workouts.
The diet was basically no more than 90carbs a day, fats from vegetables with no added oils - very limited dairy, eggs but no meats and no more than 4oz of fish at any meal.
Snacks were popcorn, veggies and Edamame hummus and very controlled nut intake.
My BMI was 26.5 and A1C was 4.8 I used 3 to 6 units 75/25 a day.
I hurt my back, stopped working out and switched to a LCHF - very very low carbs diet -, meats added oils, carbs from veggies only, lots of cheese etc.
No more snacking on popcorn but cheeses, peanut butter and nuts.
Basically, my weight increased in 9-months to BMI 31.5 and A1C to 5.3 but insulin sky rocked to 9 to 18 units of 75/25 ( on a super low carbs.
4-weeks ago I started on the NC diet and things are turning around, weight loss, good fasting Blood sugars 4.2 to 4.8
I do the shakes and tons of veggies either in soups or stir fried with no oils
Here is my take away:
Dr. Bernstein who promotes the LCHD, eats a low calorie diet that is under 1,400 calories a day with strict portion control. He also does High Intensity workouts every day.
For me portion control and the love of fatty salty foods and fruits has always been an issue.
If I am eating or snacking on veggies, popcorn and a cup turns into a ton, I'm not going to injest that many calories - " I just over ate an extra head of cabbage oh no I've eaten 50 calories ".
If I have to increase my insulin to cover, there is not much nutrients that are going to be forced into my fat cells.
On the other hand if a few nuts turn into a couple handfuls or 4oz of pork belly turn into 12oz or a piece of cheese turns into a hunk, I've just eaten a **** load of calories.
Myself, I'm going to by nature overeat and I can't count on my exercising to help control my weight - as my bad back proved that fact.
A diet of low density carbs and low density calories is best for my body type ( genes ) and personality.
One last thing, for me adding as much muscle as one can is super helpful in controlling BG even dawn phenomena. I've even timed my food and insulin injections around weight lifting.
One does not need to go to a gym nor have tons of weights - a kettle ball and a few sets of dumbells are enough and the fortitude to push yourself to muscle failure and then again ( no matter how low the weights - standing wall push ups work too just push to failure ) to open the path ways to accept the nutrients for muscle growth.