The Effects of Different Quantities and Qualities of Protein Intake in People with Diabetes Mellitus

Abstract

The recommended amount and quality of protein in diets of diabetic patients are highly controversial. In order to provide evidence-based information, the Diabetes Nutrition Study Group (DNSG) used a grading procedure used for quality of evidence and strength of recommendations (GRADE). A protein intake of 10% to 20% of energy intake (E%) or about 0.8 to 1.3 g/kg body weight in people below 65 years of age, and 15% to 20% of E% in people above 65 years of age appeared safe in weight-stable conditions. There were no intervention studies addressing metabolic effects, mortality, or cardiovascular events over prolonged periods. Body weight is closely linked to metabolic control and high protein diets are often recommended. Weight-loss diets that include 23% to 32% of E% as protein for up to one year reduced blood pressure and body weight slightly but significantly more than lower protein diets, whereas blood lipids, fasting blood glucose, and HbA1c improved similarly with higher or lower protein intakes in participants with a glomerular filtration rate (GFR) >60 mL/min/1.73 m2. Patients with a GFR <60 mL/min/1.73 m2 did not show a faster decline of GFR or kidney function with protein intakes around 0.8 g/kg body weight as compared with lower intakes, thereby arguing against a restriction. The effects of protein intake on diabetic eye or nerve disease have not been reported. There are a number of studies that have compared different types of animal proteins (milk, chicken, beef, pork, and fish) or compared animal with plant protein in diabetic patients and have reported a greater reduction of serum cholesterol with plant protein. In summary, the suggested range of protein intake appears to be safe and can be adapted according to personal dietary preferences.

The Low-Carbohydrate Diet: Short-Term Metabolic Efficacy Versus Longer-Term Limitations

“…A relative paucity of dietary fibre intake in the LCD (from the predominance of animal-based high fat and high protein foods, and relative lack of plant-based foods that contain carbohydrates in the form of dietary fibre) may cause constipation and other health problems [ 44 ]. Over the longer term, these imbalances of macronutrient intake can have potentially deleterious effects that stem from relatively high dietary intakes of fat (such as dyslipidaemia [ 12 ]) and protein (such as impaired glomerular filtration rate demonstrated in women with mild renal impairment, but not in healthy subjects with eGFR > 60 mL/min/1.73 m 2 [ 11 , 45 , 46 , 47 ]). Furthermore, diets that have both low and high percentages of carbohydrates associate with increased mortality, with minimal mortality risk at 50–55% carbohydrate intake (with a plant-based diet) [ 48 ].…”

“…In a large prospective cohort study with 1-year follow-up, consumption of energy from protein at the expense of energy from fat or carbohydrates actually increased the risk for the development of T2D [ 53 , 54 ]. Conversely, a recent guidelines publication by the Diabetes and Nutrition Study Group (DNSG) justified higher protein diets (up to 20% and 1.3 g/Kg body weight) for the treatment of T2D, providing normal renal function [ 47 ]. Interestingly, there appears to be a contradiction between the epidemiological and interventional studies on high-protein diets, with the latter (20–30% daily energy requirements from dietary protein in the context of a healthy dietary intake of fats, fibres and vegetables) showing consistently favourable metabolic outcomes and biomarkers.…”

Type 2 Diabetes Remission and Lifestyle Medicine: A Position Statement From the American College of Lifestyle Medicine

“…there are no real long-term intervention trials on high protein diets in people with diabetes. 81 . .…”

Evolving Nutritional Therapy for Diabetes Mellitus

“…The attitude to high protein diets is controversial, as the current ADA's recommendations [3] and that of the Diabetes and Nutrition Study Group (DNSG) for EASD are aiming to present [16]. This controversy originates from the fact that there are no real long-term intervention trials on high protein diets in people with diabetes [16]. Furthermore, ADA's recommendations also include some reservations with regard to high protein diets [3].…”

“…Furthermore, ADA's recommendations also include some reservations with regard to high protein diets [3]. A recent meta-analysis published in Nutrients concludes that the safety of high protein diets has been documented for one year only [16]. As said above, the quality or quantity of dietary protein does not seem to play any role in the pathogenesis of type 1 diabetes, whereas, regarding type 2 diabetes, higher intakes of red meat and processed meat products have been consistently associated with the increased risk of type 2 diabetes [12] and other chronic non-communicable diseases [13].…”