A multipurpose national household survey was conducted among Jordanian adults over a period of 4 months in 2017. A multistage sampling technique was used to select a nationally representative sample from the population of Jordan. A village or city was selected from each of the 12 governorates of Jordan. The sample of households was chosen in 2 stages. In the first stage, well-defined geopolitical areas were selected from each village or city. The second stage of household selection involved choosing a random sample of households using a systematic sampling technique in each selected area. A team of 2 people (1 woman and 1 man) visited the selected households, explained the study, and invited the members of each household to report to the health center in the selected area after fasting all day. Subjects were asked not to take their medications that day and to bring their medications with them to the health center. Subjects aged ≥ 18 years were eligible for inclusion in the study.

Data were collected using a structured, validated, and pilot-tested questionnaire administered by trained interviewers. The questionnaire was identical to one used in a 2009 survey. This questionnaire included items intended to assess the socio-demographic variables and clinical characteristics of participants, including selfreported diagnoses and treatment of diabetes and hypertension. Three blood samples were drawn from a cannula inserted into the antecubital vein and used for the laboratory measurements. Tubes containing sodium fluoride potassium oxalate were used for the blood glucose measurement. Samples were centrifuged within 1 hour at the survey site and transferred in separate labeled tubes in ice boxes to the central laboratory of the National Center of Diabetes, Endocrinology, and Genetics in Amman, Jordan. All biochemical measurements were carried out by the same team of laboratory technicians using the same method. Fasting plasma glucose was measured via the glucose oxidase method using a Roche cobas analyzer (F. Hoffmann-La Roche Ltd., Basel, Switzerland).

Several different anthropometric measures—WC, BMI, WHR, and WHtR—were calculated to define overweight and obesity. Weight was measured with subjects minimally clothed without shoes using digital scales (Seca GmbH, Hamburg, Germany). Height was measured using a portable stadiometer (Seca 214, Seca GmbH). BMI was calculated as weight in kilograms divided by height in meters squared. WC was measured midway between the iliac crest and the lower rib margin, over light clothing and using unstretchable tape (Seca 203, Seca GmbH), without exerting any pressure on the body surface. WHR was calculated as WC divided by HC, and WHtR was calculated as WC divided by height in centimeters. All measurements were taken by the same team of well-trained persons using the same tools.

Overweight and obesity were defined using various criteria and standards. Based on BMI, overweight was defined as a BMI ≥ 25 kg/m² and < 30 kg/m², while obesity was defined as a BMI ≥ 30 kg/m². Based on WC, obesity was defined using the Adult Treatment Panel III criteria (WC ≥ 88 cm for women and ≥ 102 cm for men) and separately using the International Diabetes Federation (IDF) criteria. As recommended by the IDF criteria, the European cut-off values were used to define obesity among Jordanian adults (WC ≥ 80 cm for women and ≥ 94 cm for men). The World Health Organization criteria (WHR > 0.85 for women and > 0.90 for men) were used to define obesity based on WHR. Participants were considered to have recently diagnosed diabetes if they had fasting blood sugar ≥ 126mg/dL (≥ 7.0mmol/L) at the time of the survey with no prior history of diabetes. Participants were considered to have recently diagnosed hypertension if they had a systolic blood pressure of ≥ 140 mmHg and/or a diastolic blood pressure of 90 mmHg at the time of the survey with no prior history of hypertension. Previous diagnoses of diabetes and hypertension were self-reported by participants. Metabolic risk factors were defined using the 2006 IDF criteria, which defined elevated triglycerides as ≥ 150 mg/dL (≥ 1.7 mmol/L) and reduced high-density lipoprotein (HDL) cholesterol as < 40 mg/dL (< 1.03 mmol/L) for men and as < 50 mg/dL (< 1.29 mmol/L) for women.

Data were entered into and analyzed using SPSS version 20 (IBM Corp., Armonk, NY, USA). Data were described using means and percentages. To permit comparison between the different surveys and with studies in other countries, age-standardized prevalence rates of obesity were derived using the world population as a standard. Additionally, 95% confidence limits were reported for these standardized rates. The chi-square test and crosstabs analysis were used to compare differences between proportions. To assess the changes in the likelihood of obesity between the 2009 and 2017 surveys, the data of both surveys were merged and analyzed after adjusting for age. Binary logistic regression analysis was conducted to determine factors associated with obesity, while other binary logistic regression models were utilized to evaluate the associations between obesity and metabolic abnormalities. A p-value < 0.05 was considered to indicate statistical significance.

The study was approved by the Ethical Committee at the National Center for Diabetes, Endocrinology, and Genetics in Amman, Jordan. Informed consent was obtained from each participant, and data were treated with strict confidentiality and used only for scientific purposes.

This study included a total of 4,056 persons (1,193 men and 2,863 women). Their ages ranged from 18 years to 90 years, with a mean± standard deviation of 43.8± 14.2 years. The demographic and clinical characteristics of the participants according to gender are shown in Table 1. Approximately 41.6% of men and 27.8% of women were older than 50 years. Men were significantly more likely than women to have diabetes, hypertension, elevated triglycerides, and low HDL cholesterol. Table 2 shows the means of the anthropometric and clinical parameters for men and women. While men had significantly higher mean WC and WHR, women had significantly higher mean HC, WHtR, and BMI. The mean values of systolic blood pressure, diastolic blood pressure, triglycerides, and fasting blood glucose were significantly higher in men, while the mean values of total cholesterol and HDL cholesterol were significantly higher among women.

Table 3 shows the crude and age-standardized prevalence rates of obesity for men and women using various definitions of obesity. Within each gender, the prevalence varied according to the definition used. According to IDF criteria, the age-standardized prevalence of obesity was 60.4% among men and 75.6% among women. As defined by BMI, approximately three-quarters of both men and women were overweight or obese. Finally, using the recommended measure of WHtR for the Jordanian population, 44.2% of men and 47.8% of women were determined to be obese.

Table 4 shows the prevalence of WC-defined obesity in men and women according to relevant demographic characteristics. In both genders, the prevalence of obesity increased significantly with age. The prevalence varied significantly according to the region of residence and was the lowest in the central region for both men and women. The prevalence did not significantly differ according to the type of residential area (urban vs. rural) in men or women. The variation in the prevalence of obesity according to smoking status was significant among men only.

The data from the 2009 and 2017 surveys were merged and analyzed to assess the changes in the likelihood of obesity as defined by WC (per the IDF criteria). Figure 1 shows the age-standardized prevalence rates of obesity among men and women in 2009 and 2017 surveys. After adjusting for age, the odds of obesity in 2017 were twice the odds in 2009 in both men (OR, 1.98; 95% confidence interval [CI], 1.61 to 2.35) and women (OR, 1.96; 95% confidence interval, 1.73 to 2.22). In both survey years, the odds of obesity increased with increasing age, peaked at 60-69 years old in both genders, and declined thereafter.

In the multivariate analysis, age, place of living, and marital status were found to be significantly associated with obesity as defined by WC (per the IDF criteria) among both men and women (Table 5). Older men and women had higher odds of obesity than younger individuals. Compared to men living in the north, those living in the central region had lower odds of obesity, while those living in the south had higher odds. Compared to women living in the north, those living in the central region had lower odds of obesity. Married people had significantly higher odds of obesity than single individuals for both genders. Current smoking among men was significantly associated with decreased odds of obesity relative to non-smokers. In men and women, the odds of obesity decreased significantly as the number of hours spent per week performing hard physical activity increased. The odds of obesity among men increased by 4% for each additional daily meal.

Table 6 shows the metabolic abnormalities associated with obesity as defined by WC (according to IDF criteria) among men and women after adjusting for age. Obesity defined in this manner was found to be significantly associated with increased odds of diabetes mellitus (ORs, 2.1 and 2.9 for men and women, respectively), hypertension (ORs, 2.4 and 2.5 for men and women, respectively), elevated triglycerides (ORs, 2.5 and 4.2 for men and women, respectively), and low HDL (ORs, 2.2 and 2.1 for men and women, respectively) after adjusting for age.