Table 1. Characteristics of studies.

			Study characteristics
Authors	Study setting	Inclusion criteria	Participant traits	Study design	Measures	Assessment quality
Al-Daghri et al. (2014) [21]	Primary care	Not pregnant, without diabetic complications (e.g., renal, neurologic, hepatic, and pulmonary disease), and without acute conditions needing immediate medical attention	T2DM: N = 37 (29 F), age 47.69 ± 1.45 years; Pre-diabetes: N = 47 (33 F), age 48.85 ± 1.46; non-DMT2: N = 66 (51 F), age 39.8 ± 1.44 years)	Controlled before-and-after study	Lipid profile, BMI, blood pressure, serum FBG, serum albumin calcium, phosphate, and vitamin D	0.68
Abduelkarem and Sackville. (2009) [22]	Community based	Taking oral antidiabetic drugs for T2DM, aged <85 years, with normal renal and hepatic function, not pregnant, English or Arabic speaking, and without any cardiovascular disease, chronic disease, or psychological or physical disability	N = 59 (32 F), aged 51 ± 11.3 years (range 28–75)	Controlled before-and-after study	General diet, specific diet exercises, foot care, self-testing, body pain, physical functioning, general health, vitality social functioning, and emotional and mental health	0.59
Mohammed et al. (2013) [19]	Community based	Diagnosed with T2DM and registered with primary health care centres and general hospital	Intervention: N = 109 (69 F), mean age = 52 ± 8.9 years; Control: N = 181 (131 F), aged 55 ± 10.7 years	Randomized controlled trial	HbA1C, FPG, BP, TC, HDL, LDL, TG, BMI, albumin-to-creatinine ratio, and diabetes knowledge, attitude, and practice	0.78
Al-Sinani et al. (2010) [25]	Secondary care	Diagnosed with T2DM	N = 98 (49 F), mean age = NA (categorised)	Controlled before-and-after study	HbA1C, FPG, HDL, LDL, TC, TG, BMI, BW, BP, total energy intake per day, carbohydrate, fat, and protein intake/d, energy intake from carbohydrate and fat/d per day, and PA	0.86
Al-Shahrani et al. (2012) [20]	Secondary care	Diagnosed with T2DM, aged >30 years, of Saudi nationality, and completed 5-day diabetic education programme	N = 438 (158 F), age = 55.84 ± 10.0 years (range 32–80)	Cohort study	HbA1c, TC, TG, LDL, HDL, BP, BW, and fasting blood sugar	0.77
Al Hayek et al. (2013) [24]	Tertiary care	Aged 18–70 years, diagnosed with T2DM ≥1 year, and of Saudi nationality	N = 104 (33 F), age = 57.3 ± 14.4 years	Controlled before-and-after study	HbA1C, HADS, adherence to dietary advice and medication, self-monitoring of blood glucose, and PA	0.59
Alasmary et al. (2013) [23]	Primary care	Diagnosed with T2DM, aged >18 years, and with poorly controlled diabetes	N = 41 (24 F), age = 56.2 ± 12.9 years (26–85)	Controlled before-and-after study	HbA1C, FPG, BP, TC, HDL, LDL, TG, and BW	0.77
Omer et al. (2015) [26]	Secondary care	Diagnosed with T2DM, male, aged 40–50 years, and with a BMI = 30.0–34.9 and HBA1C of 9–10%	N = 400, age = NR	Controlled before-and-after study	HbA1C, dietary habits, PA, and adherence to medication	0.27

BMI: Body mass index, BP: Blood pressure, BW: Body weight, F: Female, FBG: Fasting blood glucose, HADS: Anxiety and depression, HbA1c: Glycosylated haemoglobin, HDL: High-density lipoprotein, LDL: Low-density lipoprotein, NA: Not available, NR: Not reported, PA: Physical activity, T2DM: Type 2 diabetes mellitus, TC: Total cholesterol, TG: Triglycerides, 0–1: 0 = poor quality, 1 = high quality