Some people with diabetes have been taught to count carbohydrates as a way of controlling their weight (so have some people who have tried the Atkins and other diets like it).

For people with diabetes who want to lose weight, aiming for 30grams of carbs per meal, 3 meals per day, no snacks, will give you 360 calories from carbs.  Any weight loss diet should have a minimum of 1200 calories daily. 30% of your calories from carbs is low, but for some people with diabetes, as a temporary measure, it may work: as long as those carb calories are from foods rich in fiber and phytonutrients.