Introduction
Childhood overweight (OW) and obesity (OB) is the global public health problem since it increases the risk of premature death, as well as developing Diabetes, cancer, heart diseases, and many other physical or social diseases and complications in adulthood [
1]. It also causes undesirable psychological consequences, such as anxiety, depression, sleep disorders and low self-esteem, which affects the social and educational relationships of children [
2,
3]. Researchers estimate that 79% of obese adolescents will become obese adults who are at increased risk of developing hypertension, and cardiovascular disease [
4]. According to the WHO report, in 2016, over 340 million children and adolescents aged 5–19 years old were diagnosed as overweight/obese [
5]. Researchers believe that the increased prevalence of obesity is the result of changes in the lifestyle of societies, such as the inactivity, collapse of energy balance, increased use of fast food and animal proteins, and increased use of technology [
2,
6]. Several studies have shown that there is a relationship between lifestyle and health, and today, lifestyle changes are considered as an essential strategy for solving chronic health problems such as obesity [
7,
8]. Most Asian countries, including Iran, are at a transition from traditional to western lifestyles. Lifestyle changes have increased the prevalence of overweight /obesity in these societies [
9]. The study by Agha-Alinejad indicated the prevalence of overweight/obesity in Iranian preschool as 12% in boys and 22.5% in girls [
10]. In 2017, non-communicable diseases accounted for 76% of total mortality in Iran [
6]. The main risk factor for these diseases is the unhealthy lifestyle (e.g., getting extra calories, inactivity, and unhealthy nutrition). Healthy lifestyle plays a vital role in improving life expectancy and is associated with a reduction in the risk of death and recurrence of many diseases [
11].
The construct of perceived threat is an individual’s perception about the seriousness of health problem [
12], and their attitudes to one’s vulnerability to its problem [
13,
14]. Previous studies demonstrated that perceived threat has a vital role in predictive to health behavior [
13,
15]. Health professionals recognize children’s lifestyle as a function of parents’ behavior, belief and life styles [
14]. Health professionals recognize children’s lifestyle as a function of parents’ behavior. Parents are considered to be the causes of the child’s BMI in the community, considering the rules for watching TV, Computer games, nutrition and using the car instead of walking [
16,
17]. Children that have low levels of physical activity are more likely to watch TV than the others, and much-watching TV may cause to increase snacking and using up of high-fat, high-sugar, or high-calorie foods and the decrease of fruit and vegetable consumption and this lifestyle may cause to greater BMI among children [
40]. Excessive use of computer and TV causes sedentary behavior in children, which is an essential determinant for developing OW/OB [
8]. The role of mother for children is highlighted because the mother directly determines the social and physical environment of the child and indirectly affects their attitude, habits, and behaviors [
14,
18]. The mother is the closest person to the child and the first person to shape their behavior and lifestyle. In multigenerational families that grandmothers have roles in preparing food for family members, even if mothers are employed the eating patterns have no significant transitions. Besides, in these situations, young children may have insufficient access to dense energy food. In the contexts that the mean of BMI Z-score is negative, the income should be dedicated to goods that are currently associated with healthy weight gain in LMIC. Because of the rapid growth in children aged 0–5 years, they require a high amount of energy. Following this, the growth of household food charges may cause only modest alterations in energy balance [
34].
Meanwhile, the mother decides on the type and amount of household food [
19]. Therefore, the mother plays an essential role in determining the weight of the child. Because people’s perception of health threats leads them to health behaviors, the present study is aimed to assess the effects of the perceived threat from obesity and mothers’ lifestyles on children’s BMI.
Factors associated with childhood overweight and obesity
Our result showed that there was about fourfold increase overweight children in mothers with BMI ≥25, (AOR = 3.91, 95% CI: 1.35, 6.86). Also, working mothers had two times likely to have overweight offspring’s (AOR = 2.37, 95% CI: 1.18, 4.21). The likelihood that birth weight ≥ 3000 g leads to overweight was two times (AOR = 3.91, 95% CI: 1.24, 5. 17).
Regarding children who spent their free time; by watching TV > 2 h/day (AOR = 3.51, 95% CI: 1.20, 8.66), and playing computer> 2 h/day (AOR = 3.4, 95% CI: 1.24, 7.32) were almost three times more likely to be overweight. Children who did not eat daily breakfast (≥4/week) were almost three times more likely to be overweight (AOR = 2.88, 95% CI: 1.19, 86.67).
Regarding to psychological factor and health promoting lifestyle constructs; perceived threat (AOR = 0.90, 95% CI: 0.85, 0.94), healthy eating (AOR = 0.83, 95% CI: 0.75, 0.89), health responsibility (AOR = 0.80, 95% CI: 0.72, 0.93), physical activity (AOR = 0.77, 95% CI: 0.65, 0.82) and stress management (AOR = 0.69, 95% CI: 0.44, 0.79) were almost less likely to be overweight (Table
3).
Discussion
We can take a significant step towards preventing obesity by studying and analyzing the causes and predictors of obesity. In the present study, the mother OB/OW is an important variable affecting childhood obesity since children having mothers with obesity are more likely to be affected by obesity. The observed relationship between the mother’s weight and the child’s weight in the present study was similar to the results from other studies [
2,
23]. For instance, in Bider-Canfield et al. study, the mother’s obesity increased the risk of the child’s obesity by 2.34 times [
24]. In a similar survey of Danielzik et al. on 5–7-year-old German children, parent’s obesity was as the most important predictor of childhood obesity [
2]. In consistent with our result, the effect of the mother’s BMI on the child’s BMI depends on both the genetics and the process of learning the mother’s behaviors and unhealthy lifestyles of children [
3]. In recent decades, there is an increase in adults BMI because of changes in nutritional style. These changes are due to taking the high amount of saturated fats, sugar and refined foods (for example Fast-food) and low fiber in the daily diet, in addition to the decline in the daily physical activity [
25,
26].
Our results indicate that the birth weight was a significant variable for predicting the preschool child’s BMI. The relationship between high birth weight and the increased risk of childhood obesity is also proven in the study of He et al. in China [
27]. The similar finding has been reported by Gulliford et al. study in Trinidad and Tobago [
28]. The relationship between high birth weight and the increased risk of childhood obesity is attributed to metabolic and endocrine activities or autonomic pathways. Furthermore, high birth weight remains a risk for obesity in children [
29‐
32]. Based on meta-analysis research, high birth weight (> 4000 g) in comparison with normal birth weights (2500–4000 g), there is a high probability of childhood overweight (OR 1.66; 95% CI: 1.55–1.77). Accordingly, increased birth weight is associated with increased overweight risk, later on, proposing prenatal overfeeding as a key risk factor that leads to long-term obesity susceptibility [
31]. Similarly, Qiao et al. [
29], found that the full range of birth weights and the association of it with childhood obesity risk demonstrated that the birth weight > 3000 g increases the OR of overweight plus obesity during childhood. Consistent with previous studies [
23,
33], in our study, a significant relationship was diagnosed between the child’s BMI and the mother’s employment. This means that the family income is likely to increase, which leads to increased purchasing power as well as increased diversity in purchasing food products. Moreover, the mother’s employment leads to the change in the child’s dietary pattern and increases the use of ready-made meals and high-calorie snacks, which consequently leads to an increased risk of developing obesity. Therefore, to illustrate the null findings several studies have specifications [
34].
Our study showed mother’s perceived threat towards obesity was a significant factor in predicting for child’s BMI. The study of Azizi et al. [
35] in tuberculosis patients revealed that effective threat perceptions are related to health decision-making. Similarly, Moore et al. [
13] indicated that perceived threat could create motivation for losing weight and having more physical activity. In another study by Kim, found that that perceived threat is a crucial structure for motivating to prevention and improve the behaviors related to obesity in boys [
36]. A recent meta-analysis of interventional studies highlights the role of perceived threat to facilitate behavior change [
37]. It seems perceived threat is a critical determinant in adopting healthy behaviors since people react well to healthy messages only when they believe they are susceptible to risk such as obesity.
In this study, the period spent on watching TV and Computer game was a significant factor in predicting of child’s BMI. This finding is in line with the study of Brug’s et al. among school children in Europe [
38], also, study of Hajian and Heidari [
9] among preschool children in Iran, both of which showed that there was a positive and significant relationship between overweight and TV viewing and playing Computer games. Similar result have been reported in Katzmarzyk et al. [
8], study in 9–11-year-old children from 12 countries, found that there was a significant relationship between childhood obesity and high TV viewing. [
8]. Moreover, A study by Kelly et al. [
39], indicated that children were exposed and influenced to high rates of TV advertising about unhealthy nutritional behaviors, which that can facilitate the consumption of unhealthy foods in children such as increased use of chips and cheese puffs [
40].
As regards Health Promoting lifestyle variables, researchers have found significant relations between dietary habits and obesity. Similarly, our result indicated that dietary habits such as daily breakfast eating were a significant factor in predicting OW/OB. In line with this finding, a study by Vanhala on Finnish children proved that skipping breakfast is an important risk factor for developing childhood obesity [
41]. The relationship between regular breakfast eating and fit weight for children could be justified by the fact that by regular eating of this main meal, the child’s appetite is full and they refuse to eat fatty snacks and junk food like chips and puffs. We also recognized that breakfast skipping and overweight/ obesity have a weak association with each other. Based on this finding the relationship between breakfast skipping, eating pathology, and obesity is not simple. For example, it is possible that eating pathology intervene in the relationship between breakfast skipping and overweight [
42].
Previous studies have shown that Health responsibility is an important factor in promoting people’s health [
43,
44]. In the present study, likewise, mothers who showed greater responsibility towards health were more likely to have normal weight children. Indeed, it seems that people who do not hold themselves responsible for their health and believe in the effect of fate, chance, and other factors on the development of diseases or health, do not try to correct their families’ unhealthy lifestyle, which consequently leads to the increased risk of developing diseases and complications like OW/OB in their families.
In this study, stress management was a significant factor in predicting of child’s BMI. Psychologists believe stress-induced overeating could be a contributing factor for obesity. In other words, when someone is stressed, they usually automatically and unconsciously look for ways to relieve their stress; the most common behavior of these people is eating, and children can learn this behavior from their mothers since parents are the children’s first role models. The study of Ng and Jeffery showed that there was a positive relationship between stress and fatty diets [
45]. In a study Harding et al. [
46], observed that people who are exposed to stress, are more likely to develop obesity. Also, Rydon et al. [
47]. Showed that women with obesity were significantly more stressed.
Some studies reported that parent unhealthy lifestyles such as physically inactive, unhealthy eating practice are among the causes of childhood obesity [
14,
18]. Similarly, in our study, mothers’ low physical activity could significantly predict the probability of developing childhood obesity. This is in line with the study of Rutledge et al. [
48], found preschoolers’ weights were related to parent lifestyles. In another study, Etelson et al. [
49], reported that parents lifestyle influence children in shaping dietary and physical activity habits. Also, an unhealthy lifestyle might increase the risk of childhood obesity. A study by Davis in Kansas City, USA showed that the parents’ healthy diet and physical activity has a vital role in creating the child’s ideal weight [
50]. This finding should be taken seriously, since reduced physical activity leads to serious consequences, such as cardiovascular diseases, cancer, hypertension, diabetes, overweight, and obesity for the public health of people around the world, and it requires special attention of health workers to change the lifestyle of individuals and encourage to sports and physical activity. Indeed, this finding shows the importance of a healthy lifestyle in the parents. The present study had several limitations: Firstly, This data was collected only from the children’s mother. Secondly, the analysis of this study was based on cross-sectional data, thus does not enable to investigate the causal relationships.