Carbohydrates in our diet are what our bodies use for energy by converting the carbohydrate into glucose. It makes sense then if we reduce our carbohydrate intake our blood glucose levels will reduce.
This approach has been successful for some people in controlling their weight and blood glucose levels.
The disadvantage for some people is that they find it difficult to follow a low carbohydrate diet when the normal diet for a lot of people is based on staple carbohydrate foods such as bread, potatoes, rice and pasta and cereals.
There is also a tendency when reduced carbohydrates are consumed that fat intake will increase and this is not always beneficial.
For more information on this approach check this link:-
https://www.diabetes.org.uk/guide-to-diabetes/enjoy-food/eating-with-diabetes/meal-plans-/low-carb