According to Gray and Threlkeld (2019) who summarised the current research and based on the American Diabetes Association, basically state the four objectives of the diet for someone with Diabetes.
Promote healthful eating patterns, emphasizing nutrient dense foods to achieve and maintain body weight goals; attain individualised blood (test) goals; and delay or prevent complications.
Address individual nutrition needs, health literacy and barriers to changes
Maintain pleasure of eating by providing nonjudgmental messages are food choices
Provide practical tools for day-to-day meal planning rather than focus on single aspects.
There is no magic ratio of protein:carbohydrates:fat here, but simple foods and calorie maintenance. Gray and Threlkeld (and ADA) (2019) do not recommend low carbohydrate diets as they are hard to maintain for most people and the concept is very broad. Instead whole grain and complex carbohydrates should be replacing high glycaemic index carbohydrates. The focus on fibre here (as is typical in complex carbohydrate foods) has many added benefits, including supporting the digestive tract and microbiome. Low-carbohydrate diet studies in Type 1 DM are limited, but some report improved HbA1c and some report severe hypoglycaemia.
Rani and Bhadada (2017) suggest a mix and match technique (with quantity) to make a healthy meal and low-calorie dessert options. This provides a very easy meal building process (i.e. protein + carb + # of vegetables or fruit) and the low calorie desserts offer the fulfillment of a craving without the spike of blood glucose that typically follows a traditional dessert option. This is definitely a very flexible and widely applicable, practical tool that comes into the ADA recommendations. The ever popular mediterranean diet (or modification thereof) seems to fit most nutritional guidelines from government institutions while being flexible enough to achieve specific goals - largely it is an anti-inflammatory, high(ish) fibre and high antioxidant diet - at it’s best. Some evidence suggests it doesn’t improve blood sugar control, though more research and clinical trials are needed with type 1 DM. There are definitely more benefical aspects of a whole plant based diet than blood sugar control, though it is an important factor in type 1 DM.
Again, making meal building simple will help balance out meals and provide more satiety and satisfactsion, as well as helping to regulate blood sugar. Remember 2 fruit & 5 vegetables, and protein at each meal is a base line for daily intake.
protein + carb + # of vegetables/ fruit