Table 1.

Summary of dietary patterns for the management of T2DM.

Dietary Patterns	Description	Level of Evidence	Adherence and Comments
Mediterranean Diet	Mediterranean diet encourages consumption of foods with high nutritional quality, such as fruits, vegetables, legumes, whole grains, cereals, tubers, roots fish, low-fat dairy products, vegetable oils, nuts, seed oils, and wine in moderation [16,132,163,164,165,166,167].	High	(1) High long-term adherence [16,132,163,164,165,166,167]. (2) There is a lot of evidence in the literature for the improvement of molecular markers, glycemic control, cardiovascular health, and weight loss [16,132,163,164,165,166,167].
Dash Diet (Dietary Approaches to Stop Hypertension)	DASH diet is similar to the Mediterranean pattern, but alcohol consumption is not encouraged and there is also sodium restriction. It consists of fruits, vegetables, legumes, whole grains, cereals, tubers, roots, fish, chicken breast, lean meats, low-fat dairy products, vegetable oils, nuts, oilseeds and sodium restriction (<2300 mg or 1500 mg for severe heart disease) [16,30,31,63,95,132].	High	(1) High long-term adherence [16,30,31,63,95,132]. (2) There is a lot of evidence in the literature for the improvement of molecular markers, glycemic control, cardiovascular health, reduce blood pressure and weight loss [16,30,31,63,95,132]. (3) Severe sodium restriction (1500 mg) requires caution and monitoring, and is indicated for some specific cases [16,30,31,63,94,95,96,97,98,99,132].
Ketogenic Diet (very low-carb diet)	A dietary pattern composed of 5–10% carbohydrates, 15–25% proteins and 60–70% fats of the total energy value (TEV). Includes raw vegetables, very low-carb fruits (avocado and strawberries), all types of meat (beef, pork, fish and chicken), full-fat dairy products, vegetable oils, animal fat and eggs. It has a low intake of fruits, legumes, whole grains, cereals, roots and tubers [16,132,167,173].	Low/ Moderate	(1) Low long-term adherence [16,132,167,168,169,170,171,172,173,174]. (2) There are many controversies in the literature [16,132,167,168,169,170,171,172,173,174]. (3) No advantages over other nutritional strategies [16,132,167]. (4) The severe carbohydrate restriction may not really be necessary and safe [16,132,167]. (5) New evidence shows results that it improves weight loss and glycemic control in the short term, but increases markers of cardiovascular risk, such as LDL cholesterol [16,132,167]. (6) This dietary pattern also can increase the risk of dehydration and hypoglycemia; there is a high probability of food monotony, low fiber and micronutrients intake [16,132,167]. (7) More studies are needed in patients with diabetes, especially in the long term [16,132,167].
Low-Carb Diet	Low-carb diet promotes reducing the consumption of ultra-processed foods. The carbohydrate intake range is 40–45% of the TEV. Encourages the consumption of fruits, vegetables, legumes, whole grains, tubers, fish, lean meats, skimmed dairy products, vegetable oils, nuts, avocados, eggs and seed oils. Carbohydrates of high nutritional quality are allowed, but without excess [16,132,167,168,169,170,171,172,173,174].	High	(1) High long-term adherence [16,132,167]. (2) In recent years, good evidence has been published in the literature for the modulation of molecular markers, glycemic control, cardiovascular health and weight loss [16,132,167,168,169,170,171,172,173,174]. (3) There are several types of protocols, and those that restrict saturated fats (<7% of TEV) and prioritize sources of polyunsaturated and monounsaturated fats show good results [16,132,167,168,169,170,171,172,173,174].
Low-Fat	This dietary pattern involves ingesting 25–30% fats within the TEV. It encourages the consumption of fruits, vegetables, legumes, whole grains, tubers, fish, chicken breast, lean meats, and skimmed dairy products. This eating pattern is similar to DASH [175,176,177,178,179,180,181].	High	(1) High long-term adherence [175,176,177,178,179,180,181]. (2) There is a lot of evidence in the literature for the modulation of molecular markers, glycemic control, cardiovascular health, reduced blood pressure, and weight loss [175,176,177,178,179,180,181].
Ornish and Pritikins (very low-fat diet)	Both eating patterns have very low fat consumption (10% fat of the TEV). They encourage the consumption of whole foods, vegetables, legumes, fruits, grains, low-fat dairy products, and egg whites [16,132,182,183,184,185].	Low	(1) Low long-term adherence [16,132,182,183,184,185]. (2) Over the years, the scientific community has lost interest in studying this type of diet, since it has low adherence, small palatability, and can possibly cause metabolic damage (hormone production, protection, and energy storage) [16,132,182,183,184,185].
Plant-Based Diet (or vegetarian/ vegan diet)	Plant-based diet consisting eat of foods with high nutritional quality, such as fruits, vegetables, legumes, whole grains, cereal, tubers, roots, vegetable oils, nuts and seed oils. In this diet there is no intake of any type of food from an animal source (intake of high-fiber foods). It encourages questioning about food choices, autonomy, and ethical and cultural issues [16,132,184,185,186,187,188,189,190,191].	High	(1) Moderate long-term adherence [16,132,184,185,186,187,188,189,190,191]. (2) There is a lot of evidence in the literature for the modulation of molecular markers, glycemic control, cardiovascular health, reduced blood pressure, and weight loss (intake of high-fiber foods) [16,132,184,185,186,187,188,189,190,191]. (3) However, this diet needs constant nutritional monitoring, because in the long term it can reduce intake of some micronutrients, such as iron, calcium, and vitamin B12 [16,132,184,185,186,187,188,189,190,191].
Paleolithic Diet	The Paleolithic diet consists of following similar eating habits as our ancestors. It encourages the consumption of all types of meat, animal fat, fruits, vegetables, roots, raw foods and all types of food that nature can offer. The habit of fasting is also recommended in this type of dietary pattern [16,132,192,193,194].	Low	(1) Low long-term adherence [16,132,192,193,194]. (2) It has become technically impossible to follow a diet identical to the Paleolithic period in Westernized society [16,132,192,193,194]. (3) More studies are needed in patients with Diabetes [16,132,192,193,194].
Intermittent Fasting	Fasting means abstaining from foods and drinks that contain macronutrients and calories. Daily caloric intake occurs within a defined eating window during the day, and there are several types of fasting protocols (16 to 24 h), aiming to enhance the production of ketone bodies [16,132,195,196,197].	Low	(1) Low long-term adherence [16,132,195,196,197]. (2) It can increase the risk of dehydration, headache, hypoglycemia, and lack of glycemic control [16,132,195,196,197]. (3) It is strongly discouraged by guidelines for patients with diabetes, mainly in diabetic ketoacidosis [16,132,195,196,197]. (4) More studies are needed in patients with diabetes [16,132,195,196,197].
Mindful Eating	The practices of Mindful Eating can help increase knowledge of the factors (physiological, environmental, or emotional) that lead to excessive food consumption and training in intuitive eating (respecting signs of hunger/satiety and chewing food). The program not only values the quantity and quality consumed, but also the pleasure of the experience, thereby changing the value of the food reward without restricting it [16,132,198,199].	Moderate	(1) Moderate long-term adherence [16,132,198,199]. (2) It is a type of nutritional strategy that has been gaining prominence in the literature with good results [16,132,198,199]. (3) However, more studies are needed to evaluate the impact of mindful eating on weight loss, glycemic control, and improvement in cardiovascular markers [16,132,198,199]. (4) Seems to be a good strategy to take care of the subjective issues of nutritional management [16,132,198,199].