Yes.
YES.
My DH found the diet restrictions so impossible he wouldn't even think about them, and started eating every unsuitable food item he could lay his hands on. His diet became worse than it was before. He was overwhelmed by the long list of DON'Ts.
Then a diabetic friend said he should just stop binging on carbohydrates and forget about 'leafy green vegetables' and fibre, or cutting out cheese and cream and just reduce the starchy carbs.
There is an excellent book called Reverse Your Diabetes by Dr D Cavan that sets it out in easy to read words.
Its on eBay for £2.99 or Amazon £9.99, or of course from your local library.
Doctors and diabetic nurses flood your shocked mind with lists of what not to eat so people just switch off and don't even try.
Also join a forum like this one for Diabetics, but start slowly by cutting down on starch and eating plenty of protein.
After 6 months of that you can cut down on other unhealthy food groups.
Even if he's a beer drinker, (which is a favourite rod to beat diabetics with) just concentrate on avoiding sugary carbs and only progress to the next step when this has been achieved.
This worked for him - till covid sent us all into binge comfort eating.
His bloods are up now, so I must start at the beginning again - first stop will be to persuade him those lovely sausage rolls are not a good idea.
Its not easy.