British Journal of Nutrition

Review - Systematic with Meta-Analysis

Effects of high-protein diets on body weight, glycaemic control, blood lipids and blood pressure in type 2 diabetes: meta-analysis of randomised controlled trials

Jia-Yi Donga1, Zeng-Li Zhanga2, Pei-Yu Wanga3 and Li-Qiang Qina1 c1

a1 Department of Nutrition and Food Hygiene, School of Public Health, Medical College of Soochow University, 199 Renai Road, Dushu Lake Higher Education Town, Suzhou 215123, People's Republic of China

a2 Department of Labor Hygiene and Environmental Health, School of Public Health, Medical College of Soochow University, Suzhou, People's Republic of China

a3 Department of Social Medicine and Health Education, School of Public Health, Peking University, Beijing, People's Republic of China


High-protein diets are popular for weight management, but the health effects of such diets in diabetic persons are inconclusive. The aim of the present meta-analysis was to examine the effects of high-protein diets on body weight and metabolic risk factors in patients with type 2 diabetes. We searched the PubMed and Cochrane Library databases for relevant randomised trials up to August 2012. Either a fixed- or a random-effects model was used to combine the net changes in each outcome from baseline to the end of the intervention. Overall, nine trials including a total of 418 diabetic patients met our inclusion criteria. The study duration ranged from 4 to 24 weeks. The actual intake of dietary protein ranged from 25 to 32 % of total energy in the intervention groups and from 15 to 20 % in the control groups. Compared with the control diets, high-protein diets resulted in more weight loss (pooled mean difference: − 2·08, 95 % CI − 3·25, − 0·90 kg). High-protein diets significantly decreased glycated Hb A1C (HbA1C) levels by 0·52 (95 % CI − 0·90, − 0·14) %, but did not affect the fasting blood glucose levels. There were no differences in lipid profiles. The pooled net changes in systolic and diastolic blood pressure were − 3·13 (95 % CI − 6·58, 0·32) mmHg and − 1·86 (95 % CI − 4·26, 0·56) mmHg, respectively. However, two studies reported a large influence on weight loss and HbA1C levels, respectively. In summary, high-protein diets (within 6 months) may have some beneficial effects on weight loss, HbA1C levels and blood pressure in patients with type 2 diabetes. However, further investigations are still required to draw a conclusion.

(Received December 14 2012)

(Revised May 29 2013)

(Accepted May 30 2013)

(Online publication July 05 2013)

Key Words:

  • High-protein diets;
  • Metabolic risk factors;
  • Type 2 diabetes;
  • Randomised controlled trials;
  • Meta-analyses


c1 Corresponding author: Dr L.-Q. Qin, fax +86 512 65880050, email


  Abbreviations: HbA1C, glycated Hb A1C