In this national 2018 Afghanistan STEPS survey, the prevalence of underweight (7.8%) was higher than in Kabul City (≥ 40 years, in 2011–2012) (1.1%) [3], in Jalalabad (25–65 years, in 2013) (6.1%) [5], in Iran 15–65 years, in 2004–2005) (5.9%) [10], in Iraq (≥ 15 years, in 2015) (3.6%) [11], in Morocco (≥ 18 years; 2017) (5.6%) [13], and Palestine (1.5%, 18–64 years, 1999–2000) [14], but similar to a national study among women (15–49 years, 8.6% vs 9.1% in this study) in Afghanistan [8], and the global prevalence of underweight (8.8% among men and 9.7% among women) [1]. The found prevalence of overweight/obesity (42.7%, ≥ 25.0 kg/m²) in this study is lower than the prevalence rates found in urban centres in Afghanistan, e.g., in Kabul City (69.3%, ≥ 40 years, in 2011–2012) [3], in Kabul (57.6%, 25–70 years, in 2015) [4], in Jalalabad (57.4%, 25–65 years, in 2013) (57.4%) [6], and in Kabul, Balkh, Hirat, Nangarhar and Kandahar (52.7%, 25–70 years, during 2013–2015) [7], in Iran (59.3%, 2016) [27], in Iraq (65.7%, ≥ 15 years, in 2015) [11], in Morocco (56.1% ≥18 years; 2017) [13], Palestine (62.4%, 18–64 years, 1999–2000) [14], and in Jordan (> 75%, ≥ 18 years; 2017) [12], but higher than global estimates (10.8% of men and 14.9% of women obesity) [1].
Findings show the double burden of undernutrition (7.8%) and overnutrition (42.7%, ≥ 25 kg/m2) in the low-income country, Afghanistan. The co-existence of undernutrition (15.6%) and overnutrition (18.0%) has also been found in low-income countries in the Asia Pacific region [28]. The trend in the reduction of underweight and increase of overweight/obesity [1, 28] seems to be confirmed in this study in Afghanistan. “Rapid dietary and lifestyle transition it is the leading direction of dual burden toward overnutrition increase and diet-related NCDs” [28, 29]. In addition, it is possible that the high prevalence of undernutrition in children under the age of five in Afghanistan [8] has led to increased overnutrition in adulthood [30]. Increased efforts on policy initiatives and lifestyle changes are needed in Afghanistan to combat the double malnutrition burden.
The the prevalence of underweight was the highest among 18 to 29 year-olds (8.9%) and among women (9.1%), which was also found in previous studies [31–33], and may be attributed to food insecurity, in particular among young women [8, 34]. Akseer et al. [8] showed that younger adolescent mothers (< 20 years) are more underweight than older mothers (20–49 years) in Afghanistan, attributing this to increased mother-child nutritional demands. Some previous research showed an association between lower socioeconomic status and underweight [17, 35, 36], but this study did not find this. One possible reason for this nonsignificant finding may be related to the measurement of economic status, which in this study was limited to the number of adult household members.
In bivariate analysis, obesity was higher in women (23.7%) compared to men (12.1%), which is in line with previous studies [5, 35, 36]. Consistent with previous research [7, 35, 36], overweight/obesity increased with age. While some previous studies [5, 35–37], found an association between higher economic status (less household crowding), education, and residing in urban areas and having overweight/obesity, this survey did not show significant associations. Similar results of a non-association between education, income, and job categories with overweight/obesity in adults in Kabul [7]. It is possible that educational level did not impact on body weight status because of the high proportion of the study population (59.0%) had no formal education. Of concern is as well that 32.3% of young people aged 18–29 years were already overweight or obese, showing that a large proportion of overweight/obesity is already established in early adulthood. Therefore, obesity interventions starting in childhood or adolescents should be prioritized in Afghanistan [38].
This study did not find an association between dietary behaviour (inadequate fruit and vegetable intake and having meals outside home) and underweight as well as overweight or obesity, unlike some previous research [17, 39, 40]. This study lacked to assess other dietary behaviours, such as frequent snaking, skipping breakfast, eating high amounts of processed or fast food, and high intake of sugary beverages, which may have been responsible for a higher rate of overweight/obesity [9, 41].
In agreement with previous studies [37–39, 42, 43], this study showed in bivariate analysis that physical activity was inversely and high sedentary behaviour was positively associated with overweight/obesity. Unlike some previous research [5, 38, 42]], this study showed no (negative) association between current tobacco use and the prevalence of overweight/obesity. As shown previously [5–7, 38, 44, 45], we found an association between NCDs (hypertension, diabetes, and raised cholesterol) and overweight/obesity. This result emphasizes the fact that adults in Afghanistan suffer from several NCD risk factors at the same time [6], calling for multiple risk factor interventions [5, 7]. Implementing preventive interventions, such as programmes improving a healthy diet, appropriate food policies, promotion of physical activity and interrupting sedentary behaviour, and community awareness campaigns may help in ameliorating the high burden of overweight and obesity. The evaluation of experimental weight reduction interventions is recommended as future research to fine-tune intervention strategies in Afghanistan.