I would recommend the "Glycaemic Index" diet, together with working on the principle of low salt/sugar/fat.
A lot of research has been done on the rate of digestion of a wide range of foods resulting in the
"Glycaemic Index" (GI) system. This book is no doubt typical of many:-
Easy GI Diet: Use the Glycaemic Index
You can build up an eating pattern using the recommended foods (e.g. basmati rice, multigrain bread, wholemeal pasta - all low-medium GI) which are slowly digested so giving a slow buildup of glucose as you work if off as energy. White bread & potatoes (high GI) are more rapidly digested & give a rapid increase in BS.
Once you've understood the system, you won't think you're dieting. Don't buy "diabetic foods" as they are sweetened with bulk laxatives. The GI diet allows normal eating but of selected foods - all aiding BS control. A bonus is that the diet is suitable for heart patients, & so protects you from the risks of heart attacks. Also I use a lot of oat bran to help control my cholesterol as I can't tolerate statins. The special margarines also help cholesterol reduction.