It takes awhile to get over your sweet tooth. But if you allow one bite from time to time it is not an impossibility.
With being a potato, bread, rice etc...cook just change to sweet potatos, red potatos, they are lower glycemic,
brown rice and
bread must be 100% whole wheat it is slower to digest and spike insulin.
So just limit those things to whatever diet he is given men get more than women and he will be ahead. Just remember the slower it absorbs the better.
Use the glycemic index for lower sugar veggies and fruits. Watermellon, pineapple and one more are the highest fruits.
steam veggies and
I use real foods no diet sugars, no artificial margerines, butter only and Oh for low glycemic sugars use the new Agave syrup it is good and slow to digest.
For cold drinks when out I use iced tea and 1/4 lemonjuice called Arnold Palmer. But I steer clear of Equal and all those sweetners. At home I mix enough juice of choice into ice water just for flavor.
Iced Soy Latte's are good and not high calorie like the cream and sugar ones. I do use a diet syrup in those but I get them once every 6 mo or so.
Good luck, AlamoAA