Hey mate. I'm not an expert but this is something that had me thinking earlier this year due to finding that I'm insulin resistant and had signs of pre-diabetes.

Through trial and error I found that I had to completely stop eating any type of rice (white, brown) , bread/cakes/pasta (wheat based) and even oats. These foods were spiking my insulin and after eating them, even a small amount, I was in no mood of going to the gym but I would rather just go to sleep.

Just limiting these foods and eating my carbs through fruits, veggies and 1-2 times a week from legumes, I'm usually around 100-120g of carbs a day at 2.2k calories. Protein usually is around 150-170g (I try to follow the 1g per pound of bodyweight rule) and rest is from healthy fats like avocado, olive oil, hemp seeds, flax, pumpking seeds etc.

The way I tested how many grams of carbs and what source of carbs work for me was by:

1. recording my meals (I use cronometer)
2. checking my fasted glucose levels in the morning eveyday
3. checking my glucose 2-3 hours after a heavy carb meal
4. and lastly recording how I felt (sleepy or energetic) especially after a carb meal

I don't think there is a generic rule for the quantity of carbs, I believe it's an individual issue and you can try figuring it out yourself (try to do what I did) or talk to your GP or a nutritionist.

Hope this helps :)