Table 1.

Summary of overweight/obesity prevalence data

Dates of study	Population sampled	Country	Sample size	Population characteristics			Definitions		Results				Quality assessment checklist(*) (Y: Yes, N: No, NA: Not Applicable)	Study limitations
				Men (%)	Age (years; range unless specified)	Residency status; area(s) of residence	Overweight (if not 25 to < 30)	Obesity (if not ≥ 30)	Prevalence overweight (%)		Prevalence obesity (%)
									Men	Women	Men	Women
1980– 198148	PC	Kuwait	1171	0	18 to >60	Kuwaiti nationals	>25			59.2		32.2	1-Y, 2-Y, 3-Y, 4-Y, 5-Y, 6-Some, 7-NA	Sample selection method not clear Limitation of the study not discussed Steps taken to minimize bias not discussed
1980–198149	PC	Kuwait	2067	43.3	18 to >60	Kuwaiti nationals	>25		21.7–69.4 (age- dependent)	as Al-Isa, 1997a (above)	8.5–24.1 (age- dependent)	as Al-Isa, 1997a (above)	1-Y, 2-Y, 3-Y, 4-Y, 5-Y, 6-N, 7-NA	Sample selection method not clear Limitation of the study not discussed Steps taken to minimize bias not discussed
1985–198827	GP	KSA	17892	48.5	18 to <61	Saudi nationals			30.7	28.4	14.2	23.6	1-Y, 2-N, 3-N, 4-N, 5-Y, 6-N, 7-NA	Sample selection method not clearly Data analysis not clear Educational/employment status of the sample not reported Limitation of the study not discussed Steps taken to minimize bias not discussed
NR28	GP	KSA	3171	45.9	>15		>27 in men,	>25 in women	30.1				1-Y, 2-Y, 3-Y, 4-Y, 5-N, 6-N, 7-NA	Unconventional definition of obesity Selection methods of houses for sampling not clear Dates of study not clear Limitation of the study not discussed Steps taken to minimize bias not discussed
1991–199251	GP	Bahrain	290	47.2	20–65	Urban/rural mix			26.3	29.4	16.0	31	1-Y, 2- Y, 3-Y, 4-Y, 5-N, 6-N, 7-NA	Selection procedure not well described Statistical analysis not described Limitation of the study not discussed Steps taken to minimize bias not discussed
1990–199329	GP	KSA	13177	52	15 to >60	Saudi nationals			33.1	29.4	17.8	26.6	1-Y, 2-Incomplete, 3-Y, 4-Y, 5-Y, 6-Some, 7-NA	The sample may not be truly representative for the general Saudi diabetic patients (sample randomly selected from National Epidemiological Household Study for Chronic Metabolic Diseases) Limitation of the study not discussed
1990–199330	PC	KSA	3261	49.5	30–70	Saudi nationals; urban/rural mix			41.91	31.55	29.94	49.15	1-Y, 2-Y, 3-Y, 4-Y, 5-Y, 6-N, 7-NA	Limitations of the study not discussed Data on the steps taken to minimize bias not clear
199231	PC	KSA	1385	0	16–70	Urban/rural mix				26.8		47.0	1-Y, 2-Incomplete, 3- Y, 4- Y, 5-N, 6- Some, 7-NA	Recruitment process not specified Data on the steps taken to minimize bias not clear
NR54	SP	UAE	215	0	18–30	Emirati nationals				19		9.8	1-Y, 2-Y, 3-Y, 4-Y, 5-N, 6-Some, 7-NA	The sample may not be truly representative for the general Emirate population (sample from UAE female university only) Limitation of the study not discussed clearly
199432	PC	KSA	1580	100	>16	Urban/rural mix			34.8		28.6		1-Y, 2-Y, 3-Y, 4-Y, 5-Y, 6-N, 7-NA	Limitation of the study not discussed
1993–199433	Military hospital	KSA	1485	46.1	18–91	Saudi nationals			40.1	31.5	21	40.5	1-Y, 2-Y, 3-Y, 4-Y, 5-Y, 6-N, 7-NA	Specific population sampled Limitations of the study not discussed
1993–199434	WP*	KSA	2990	NR†	<25 to >60	94.7% Saudi nationals			30.3		24.5		1-N, 2-N, 3-N, 4-N, 5-N, 6-Y, 7-NA	Sample selection methods not well described Potential of selection bias samples misses more complicated cases ('referred to hospital clinic') Sampled population relatively unrepresentative of general population(National Guard employees and dependants) Data on the steps taken to minimize bias not clear
1993–199447	PC‡	Kuwait	1705	0	18 to >60	Kuwaiti nationals	>25			72.9		40.6	1-Y, 2-Y, 3-Y, 4-Y, 5-Y, 6-N, 7-NA	Limitations of the study not discussed Data on the steps taken to minimize bias not clear
1993–199448	PC§	Kuwait	3435	50.3	18 to >60	Kuwaiti nationals	>25		44.3–75.1 (age- dependent)	as Al-Isa, 1997a (above)	17.1–35.6 (age- dependent)	as Al-Isa, 1997a (above)	1-Y, 2-Y, 3-Y, 4-Y, 5-N, 6-N, 7-NA	Limitations of the study not discussed Data on the steps taken to minimize bias not clear
NR55	SC	UAE	4075	43.9	6–17	UAE nationals	Overweight 85th–95th percentile Obesity >95th percentile or BMI >30		8.5	9.3	7.9	7.9	1-Y, 2- Incomplete methods of selection, 3- Y 4- Y, 5-N, 6- partially, 7-NA	Method of study sample recruitment not clear Lack of standardization Data on the steps taken to minimize bias not clear
NR35	SC	KSA	14660	42.0	14–70	Saudi nationals			27.23	25.20	13.05	20.26	1-Y, 2-Y, 3-Y, 4-N, 5-N, 6-N, 7-NA	Data analysis was not discussed clearly Study limitations not discussed Steps taken to minimize bias not discussed
NR52	GP	Bahrain	2013	58.0	Men 40–59 Women 50–69	Bahraini nationals			39.9	32.7	25.3	33.2‡‡	1-Y, 2-Y, 3-Y, 4-Y, 5-Y, 6-N, 7-NA	Limitations of the study not discussed Method of blood sampling not clear
1998 – 199956	SC	UAE	898	0	11–18		Overweight: 85th –95th percentile Obesity: > 95th percentile			14		9	1-Y, 2-Y, 3-Y, 4-Y, 5-Y, 6-Some, 7-NA	Results might be biased as all the measurements were collected by one investigator only Limitations of the study not discussed
1998–200050	WP**	Kuwait	9755	48.0	Mean age + SD: Women 33.3 + 11.6; Men 29.2 + 8.2	Kuwaiti nationals			38.3	32.8	27.5	29.9	1-Y, 2-Incomplete, 3-N, 4-N, 5-N, 6-N, 7-NA	Sample recruitment method not discussed clearly Data analysis not clear Study limitations not discussed Steps taken to minimize bias not discussed
1998 – 199957	SC	UAE	4381	49.6	5–17	48.0% UAE citizens; 81.7% urban	IOFT criteria		19.2	19.8	13.1	12.4	1-Y, 2-Y, 3-Y, 4-Y, 5-Y, 6-N, 7-NA	Secondary data analysis Limitations of the study not discussed
1998–200049	WP**	Kuwait	740	100	45–80	Kuwaiti nationals					37		1-Y, 2-Y, 3-Y, 4-Y, 5-N, 6-Some, 7-NA	Sample recruitment method not discussed clearly Study limitations not discussed Steps taken to minimize bias not discussed
1999–200066	WP††	Kuwait	3282	85	54 % <40	62% Kuwaiti nationals			48		27		1-Y, 2-Y, 3-Y, 4-Y, 5-N, 6-N, 7-NA	Data on the population characteristics including age and ethnic origin was limited Details on the method of blood sampling was not clear Study limitations not discussed Steps taken to minimize bias not discussed
1999–200058	GP§	UAE	724	0	20 to >60	UAE nationals		30–40		27		16	1-Y, 2-Y, 3-Y, 4-Y, 5-Y, 6-N, 7-NA	Potential of sample selection bias (recruitment via students at one university) Steps taken to minimize bias not discussed
200061	GP	Oman	5838	49.8	20 to >80	Omani nationals; urban/rural mix			28.9		18.5		1-Y, 2-Y, 3-Y, 4-Y, 5-N, 6-N, 7-NA	Procedure for determining BMI not reported Steps taken to minimize bias were not discussed Limitations of the study were not discussed
NR36	GP	KSA	11208	41.3	20–70	Saudi nationals			32.82	29.09	15.21	23.97	1-Y, 2-Incomplete, 3- Y, 4-Y, 5-N, 6-N, 7-NA	Method not discussed clearly Sample selection was not clear Study limitations were not discussed Steps taken to minimize bias were not discussed
1999– 200059	GP	UAE	5844	42.8	20 to >65	UAE residents; '80% urban'			48	35	24	40	1-Y, 2-Y, 3-Y, 4-Y, 5-Y, 6-N, 7-NA	Sampling method of purposely biased population 'non-institutionalized' Steps taken to minimize bias were not discussed
200062	GP	Oman	5847	48.8	20 to >60	900 urban; 4947 rural					19.1		1-Y, 2-Incomplete, 3-Y, 4-Y, 5-N, 6-Y, 7-NA	Secondary data collection Data on the steps taken to minimize bias not clear
2001–200237	SP	KSA	701	100	Mean age 21.7 years	Saudi nationals			31		23.3		1-Y, 2-Y, 3-Y, 4-Y, 5-Y, 6-Some, 7-NA	The selected sample might not be representative for the whole population ( the selected sample might not be representative sample ) Data on the steps taken to minimize bias not clear
2001–200267	YP	KSA	894	100	12–20				13.8		20.5		1-Y, 2- Incomplete, 3-N, 4- Y, 5-N, 6- N, 7, NA	Sampling method not discussed clearly Data analysis not clear
2004–200560	PC	UAE	817	49.3	20 to >60	UAE nationals					28.3	46.5	1-Y, 2-Y, 3-Y, 4-N, 5-Y, 6- N, 7-NA	Statistical analysis was not described clearly Study limitations not discussed
NR38	SP	KSA	241	100	Mean age + SD: 21.2 + 1.3				29.9		16.6		1-Y, 2-Y, 3-Y, 4-N, 5-N, 6-N, 7-NA	Data analysis was not described clearly Study limitations were not discussed Steps taken to minimize bias were not discussed
2007 – 200865	GP	Qatar	1117	51.1	20–59	Urban/semi-urban			31.9		45.2		1-Y, 2-Y, 3-Y, 4-Y, 5-Y, 6-Some, 7-NA	The selected sample might not be representative sample As the recruitment of subjects is from primary healthcare centres, there may be a possibility that this sample is biased
200539	SC	KSA	19317	50.8	5–18	Saudi nationals	WHO 2007 criteria		24.8	28.4	10.1	8.4	1-Y, 2-Y, 3-Y, 4-Y, 5-Y, 6-N, 7-NA	Limitations of the study not discussed Data on the steps taken to minimize bias not clear

Summary of cross-sectional studies investigating the prevalence of overweight/obesity in the GCC region

*Employees of Saudi National Guard and dependents

^†‘Mostly settled tribal men’

^‡Attendees at primary healthcare centres with minor complaints, plus accompanying persons

^§All subjects recruited via family member at UAE University

**Adult attendees of the Kuwait Medical Council and Public Authority for Social Security (government employed/retired population)

^††Employees of Kuwait Oil Company

^‡‡Age-adjusted data

(*)Quality assessment checklist adapted from the Centre of Reviews and Dissemination guidelines (CRD) for non-randomized studies:

(1) Was the aim of the study stated clearly?

(2) Was the methodology stated? And was it appropriate?

(3) Were appropriate methods used for data collection and analysis?

(4) Was the data analysis sufficiently rigorous?

(5) Were preventive steps taken to minimize bias?

(6) Were limitations of the study discussed?

In systematic review, was search strategy adequate and appropriate?

PC = primary healthcare-registered population; GP = general population; WP = working population; SC = schoolchildren; SP = student population; YP = young population