European Journal of Cardiovascular Medicine

Obesity is a fast growing problem not only in developed countries but also in developing countries like India and it is now known to be associated with increasing various health risks. In India, overall prevalence of obesity in adolescent children is 4.8%out of which prevalence of obesity in adolescent boys is 5.2% and among adolescent girl is 4.3%.³ Obesity is a risk factor in development of short stature, school teasing, precocious puberty, hypertension, diabetes, gall bladder disease and coronary heart disease, certain type of cancers and other co-morbidities even at early age than usual.⁴Obesity is also one of the reasons for loss of years due to various morbidities, immobility, limited physical activities, social stigma and many other conditions. Understanding the prevalence trend, factors contributing in developing obesity, early diagnosis and treatment are key factor for prevention of obesity and obesity related complications  later in life. To achieve this goal, it is important to identify various risk factors and predictors in the community to prevent it before it occurs.⁵

Cross sectional analytic study was conducted at six different schools of ahmedabad district with aim to study the predictors of obesity in adolescents. The study was conducted for a duration of 1 year (1st July 2022 to 31st June 2023) involving 3 schools from urban area and 3 schools from rural area of Ahmedabad district. These 6 schools were identified by simple randomization technique using lottery method. Prior approval for the study was taken from the concerned school authorities and ethical approval was also taken from the institution ethics committee before initiation of study. All the children who were studying in these schools whose age is between 10 to 16 years were included after taking informed and written consent after briefing about the study to parents and the children in local language. Adolescent students whose age was more than 16 years, adolescent age group between 10 to 16 years but having any comorbidities or who have not provided consent were excluded from study. 

Basic demographic features like age, sex, socioeconomic class, religion, including birth history, diet history, developmental history, family history were recorded in a pre structuredproforma of identified adolescents.  Detailed physical examination was done in all the children which comprises anthropometric measurements(BMI, US: LS ratio, Waist circumference, Hip circumference and Waist/Hip ratio and skin fold thickness), general and systemic examination were done and its findings were recorded in proforma. Standardized questionnaire forms were prepared in the local language and given to parents and children and were asked to fill by their own to identify various risk factors of obesity. Questionnaire forms include age, grade, birth date, birth weight, school name, education of parents, occupation of both parents, nutritional status of parents, details regarding their meal consumption e.g. type of diet, calorie intake per day of previous three days via 24 hour recall method, number of meals consumed per day, portion of individual meal, snacks consumed throughout the day in between the meals and their portion, meal skipping pattern, outside eating habit, fast food consumption, personal hobbies, use of gadgets and social media, eating while watching TV, physical activity scaling, outdoor sports activities, sleeping pattern with duration, present BMI of mother and father, school environment. Duly filled questionnaire forms were analyzed and their findings were recorded in proforma. After the collection of data children were divided into 3 categories - BMI <85^th centile, pre obese and obese based on their BMI. Detailed analysis of predictors which were present in these 3 groups were done using appropriate statistical techniques and various predictors were identified.

During the study period 500 adolescents were enrolled out of which 277 (55.4%) were male and 223(44.6%) were female. Mean age of study population is 13.6±1.7. 250 adolescents were enrolled from schools belonging to urban area and male to female ratio in urban area is 1.35 and 250 adolescents were enrolled belonging to rural area and male to female ratio in rural area is 1.13.

In present study 325 adolescents have BMI <85^th centile, 112 adolescents have BMI between 85th -95th centile and were identified as pre-obese/overweight and 63 adolescents have BMI >95th centileand  were identified as obese.Incidence of overweight in present study is 35%and incidence of obesity is 12.6%. 46 % obese children in study population were in age group of 15-16 years and 90.4% were belonging to mid adolescent age group. Mean age of obesity is 14.9±2.4 years. 36.6 % pre-obese children in study population were in age group of 15-16 years and 66.6% adolescent were belonging to mid adolescent age group and mean age of this group is 14.9±2.4 years.

Obesity was significantly associated when per day calorie intake is >2000 k.cal (p < 0.0001), when adolescent is eating snacks  ≥2 times per day in between in the meals(p = 0.0012), when adolescent is eating  ≥2 times per week outside the home (p = 0.0067), when adolescent is eating junk food  ≥2 times per week(p < 0.0001) and when adolescent uses screen  for >60 min duration while eating. There were no statistically significant correlation was observed with skipping of meals and incidence of obesity in present study.

In the present study, obesity was significantly associated when adolescent sleeps >8 hrs per day(p = 0.00032), when adolescent uses gadgets for >60 min duration(p = 0.0083), when adolescents duration of physical activity is <30 min per day and when adolescent have light and very light grade of physical activity(p = 0.00073).

Table 1: Correlation of Eating habits with adolescent overweight and obesity

Table 2: Correlation of Physical activity, Sleep and screen time with adolescent overweight and  obesity

Incidence of obesity is 12.6% and overweight is 35% in the study population.In other comparable study by S Seema et al  incidence of obesity was 6.8% and overweight was 17.1%.⁶Another study by Harish Ranjani et al showed prevalence of combined obesity and overweight to be 19.3 %.⁷this suggest significantly high prevalence of obeisty present study compared to other studies; it may be due to study was done after post COVID era.Incidence of obesity in urban area is 20.4% and rural area is 4.8%. Study done by  Smith et al who had done inurban Indian school children reported overweight prevalence of 18.5% and obesity of 5.3%.⁸This  suggest recent increase in incidence of obesity in urban population in last decade and warrant urgent attention for  prevention of obesity in community.

Mean age of obesity is 14.9±2.4 years in present study.Mean age of obesity in Pelegrinietal.⁹and Selvi et al¹⁰ were 15.22±1.87 years (p value < 0.05) and 15.7±1.43 years (p value < 0.05) respectively.This suggest obesity is more common in mid adolescent age group. Maximum growth and growth spurt also occur in this group, hence tracking BMI in this group is necessary to track obesity and its complications later in life. Sex ratio of obese adolescent is 1.52  and overweight adolescent is 1.8 (p= 0.054); incidence of overweight and obesity is almost equal in the both sex. Smith et al⁸ study had shown obesity is more common in male (p value 0.036) and Hari Krishnan et al¹¹ study had reported obesity is common in girl adolescents (p value <0.05).

In present study obesity and overweight is most common in upper middle class with 30(47.6%) and 50(44.6%) adolescents respectively, followed by upper class with 16(25.4%) and 28(8.6%)  respectively. Present study suggest overweight and obesity are even now alarming and emerging even in middle class not restricted it to only upper class(p = 0.0023). 

Out of 63 obese adolescents, 4(6.3%)  had obese mother, 16 (25.3%) had overweight mother and 43(68.2%) had mother with BMI <85^th centile; similarly 16(25.3%) had obese father, 14(22.2%)  had overweight father and 33(52.3%) had father with BMI <85 centile for age and sex. Present study and study done by Shariff et al¹²  had showed significant association between maternal and paternal obesity with the children obesity(p < 0.001  and p = 0.0034 respectively). These could be due to sharing same genetic makeup, similar food habits and lifestyle in family.

Out of 63 obese adolescents, 22(34.9%) were having calorie intake of more than 3000kcal/day and 39(61.9%) obese were having calorie intake between 2000-3000 kcal/day. Obesity is significantly associated when per day calorie consumption exceeds more than 2000 kcal (p <0.0001).  In Srivatav et al¹³  also reported 89.2% obese adolescents had calorie intake >2000 kcal/day. 26(41.2%) obese adolescents were eating snacks more than 3 times per day in between the major meal and 32(50.7%) obese adolescents eating 1-3 times per day in between the major meal. 28(25%) overweight adolescents eating snacks more than 3 times per day in between the major meal and 75(66.9%) overweight adolescents were eating 1-3 times per day in between the major meal.  Li and Dibley et al¹⁴  study and present study had shown significant association of eating snacks more than 3 times per day in between the major meal and obesity (p <0.05 and p 0.0012 respectively).

10(15.8%) obese adolescents were eating  >3 times per week outside and 39(61.9%) were eating 2-3 times per week. Eating  ≥2 times outside per week  is  significantly  associated with incidence of obesity in present study(p 0.0067). In present study 30.1% obese adolescents and 16.9% overweight adolescent were eating  >3 times junk food/week; 50.8% obese adolescents and 46.4% overweight adolescents  were eating 2-3 times junk food/week. Eating junk food ≥2times/week is significantly associated with incidence of obesity and overweight in present study(p <0.0001). Present study has shown there is no correlation has been observed between skipping of meal and incidence of obesity.

41(65%) obese adolescents had physical activity of  <30 min while 20 (31.7%) had 30-60 min duration. 43(38.4%) overweight adolescents had physical activity of <30 min and 53(47.3%) had 30-60 minutes. Adolescents with  >60 minutes of regular physical activity per day have only 2.7% chance of being overweight. Physical activity < 30 minutes per day is significantly associated with overweight-obesity in present study(p 0.0023). Ghavamzadehet al¹⁵ study showed 8% individuals with regular physical activity had developed obesity. Daily physical activity of at least 30-60 minutes can  prevent obesity. Out of 63 obese adolescents, 2(3.2%) had moderate grade of physical activity, 40(63.5%) had very light physical activity and 21(33.3%) had light grade of physical activity. Out of 325 adolescents with BMI <85th centile, 12(3.6%) had vigorous grade of physical activity, 192(59.1%) had moderate grade of physical activity, 100(30.8%) had light physical activity and 21(6.4%) had very light grade of physical activity. There is statistically significant association between light and very light grade of physical activity and obesity in adolescents in present study with (p = 0.00073). There is inverse correlation between moderate to vigorous grade of physical activity and incidence of obesity in the present study.

Out of 63 obese adolescents, 8(14.3%) had >10 hours of sleep , 49(78%) had 8-10 hours of sleep and 2(3.8%) had  <6 hours of sleep. Sleep duration more than 8 hours per day is significantly associated with obesity and overweight in present study(p 0.00032) and Landhuis et al¹⁶ (p 0.04).

20(31.7%) obese adolescents had screen time180-240 min per day, 25(39.6%) had  60-180 min, 15 (23.8%) had  30-60 min and 3(4.7%)  had  <30 min per day. Screen time  >60 minutes is significantly associated with obesity in  present study(p= 0.0083). Excessive engaging in screen time limits outdoor and physical activities which in turn increase incidence of obesity. 40(63.4%) obese adolescents had habit of watching TV for >60 min, 13(22.2%) obese adolescents were watching for 30-60 min and 10(15.8%) were watching for <30 min while eating. Watching TV for  >60 minutes while eating is significantly associated with obesity in present study (p 0.0014) and Utter et al¹⁷ (p = 0.03). Watching TV while eating could lead to excessive eating resulting in obesity.

Obesity is more common in middle adolescent age group as compared to early adolescent in present study. Living in urban area, educated parents (graduate and post-graduate), overweight-obese Mother, Overweight-obese father, eating two or more than two times outside per week, eating snacks two or more than two times per day, eating junk food two or more than two times per week, eating while watching TV, calorie intake more than 2000 Kcal per day are identified predictors for increase in risk of overweight and obesity in early-mid adolescent age group in present study

Limitations

Present study has included only school going adolescent age group of 10-16 years age excludes adolescent from late adolescent age group.

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