17

Chapter- IIREVIEW OF RELATED LITERATURE

The review of literature is an instrument in the selection for topic, formation of hypothesis and deductive reasoning leading to the problem. It helps to get a clear idea and support the finding with regard to the problem under study. Study of related literature implies locating reading and evaluating reports of research as well as reports of casual observation and opinion that are related to the individuals planned research reports. A study of relevant literature is an essential step to get a clean idea of what has been done with regard to the problem under study. Such a review brings about a deep and clear respective of overall field.Wang, et al., (2009)[footnoteRef:2] conducted a study on Differences of height and body mass index of youths in urban vs. rural areas in Hunan province of China the background of the study was the economic reforms in China were implemented approximately 30 years ago. Since then, people's nutrition, living conditions and overall health have continually improved, but there has been an imbalance between the progresses in urban vs. rural areas. Height and body mass index (BMI) are regarded as two important indicators of nutritional status and overall health. The aim of this study was to investigate differences in height and BMI between Chinese youths of rural vs. urban areas and further, to determine whether these differences have changed over time (1990s vs. 2000s). The Subject and methods of the study was the 24 194 urban youths and 7130 rural youths were recruited in Hunan province of China. In each gender group, the subjects were divided into eight subsets according to age, geographic area residence, and decade when the youths were measured. Independent t-tests were used to test the differences of height and BMI between the studied groups. The Results of the study was both male and female youths from urban areas were significantly taller than youths from rural areas in both the 1990s and 2000s (all p14 years of age). They documented that the prevalence of obesity was 13% in males and 20% in females, and the prevalence of overweight was 27% in males and 25% in females. The prevalence of obesity was highest in the females in the central province and in the males in the western province, 19 while overweight was more prevalent in both male and female populations in the central province. Generally, obesity was more common in females and overweight was more common in males. [10: M. A. El-Hazmi et al., (1997). Prevalence of Obesity in the Saudi Population. Ann Saudi Med, pp.302-306.]

Sidoti, et al., (2009)[footnoteRef:11] conduct the study Body Mass Index, Family Lifestyle, Physical Activity and Eating Behavior on a Sample of Primary School Students in a Small town of Western Sicily. Obesity is actually a discernible issue in prosperous western society and is dramatically increasing in children and adolescents. Many studies indicate that obesity in childhood may become chronic disease in adulthood and, particularly, those who are severely overweight have an increased risk of death by cardiovascular disease. Understanding the determinants of life style and behavior in a persons youth and making attempts to change childrens habits is considered a key strategy in the primary prevention of obesity. This study aims to find a correlation between Body Mass Index, (BMI), physical activity and eating behaviour and to identify, eventually, risks, protective factors and possible directions for interventions on incorrect nutritional/physical activity and intra-familiar life styles in a sample of young adolescents in a small town of Western Sicily. The research surveyed the entire population of the last three curricular years of two Primary Schools in a town of western Sicily, (n=294). The instrument used for the survey was a questionnaire containing 20 different items with multiple choices answers. Personal information, physical activity and eating behaviors were collected both for parents and students to cross students and parents characteristics. Data were codified and statistical analysis was computed through Statistics and Openstat software Data obtained demonstrated a relevant percentage (18%) of obese children. Prevalence of overweight was high as well, (23%), and many in this area (12%) were at risk since they were on the limits of the lower class. A significant association was found between the percentage of students classified as having an elevated BMI and a sedentary habit and/or an incorrect eating behavior. Among the overweight and obese children a direct statistical association was also shown between the weight of their parents and some daily life styles. An inverse association, on the contrary, was observed between those variables and the cultural level of the family. Cultural level, in fact, was significantly associated with having breakfast, fruit and vegetable consumption and practice of physical exercise. Multi linear regression analysis showed the weight of some independent variables which were more strictly correlated with childrens BMI. Increasing the proportion of adolescents meeting recommended dietary and physical activity guidelines has been identified as an important strategy to contrast the epidemic increase in obesity, especially in western countries. This study stressed the need to increase the knowledge and monitoring of the consequent behaviors of adolescents with regards to dietary habits and the practice of physical activity. School, communities and families are considered the best pathways to disseminate correct information and knowledge and the more suitable channels to raise the awareness of the importance of correct dieting and regular physical activity School and community-based intervention programs are, then, strongly requested to activate preventive actions early in life and mainly in the development age. The importance of the family and of the social context factors in health behavior was also emphasized. A familiar eco-systemic model that takes into account the whole bio-social-psychological aspects was also sustained for a global therapeutic approach to the obese child. [11: Enza Sidoti et al., (2009). Body Mass Index, Family Lifestyle, Physical Activity and Eating Behaviour on a Sample of Primary School Students in a Small Town of Western Sicily, Italian journal of public health vol.6, N. 3.]

Ardalan, et al., (2007)[footnoteRef:12] conduct the study Association of Physical Activity and Dietary Behaviors in Relation to the Body Mass Index in a National sample of Iranian Children and Adolescents: CASPIAN Study. To examine the relation of dietary and physical activity (PA) patterns with the body mass index (BMI), and the associations between these patterns among children. .A representative sample of 21 111 school students aged 618 years was selected by multistage random cluster sampling from 23 provinces in the Islamic Republic of Iran. PA and dietary pattern were assessed by self-administered validated questionnaires. Fruit and vegetables, dairy products and snacks (salty, fatty or sweet) had a similar consumption frequency of approximately twice a day. The type of fat most frequently consumed was hydrogenated solid fat (consumed by 73.8% of families). The PA level was significantly higher among boys than girls, in rural than in urban residents, and in intermediate students than high-school students. Among boys, the frequency of consumption of vegetables and plant proteins (R=0.46); and among girls, the frequency of consumption of dairy products and fruits, as well as high PA level had a significant inverse association with BMI (R=0.57). Among boys, the low frequency of consumption of fruits, the time spent on PA and the energy expenditure; and among girls, the time spent on PA and the energy expenditure, had significant relationships with overweight. When controlling for covariates, PA levels had significant relationships with the frequency of consumption of all food groups. Unhealthy lifestyles make Iranian young people prone to chronic diseases later in life. When examining their health benefits, the interrelationship of dietary and PA behaviors should be considered. [12: Gelayol Ardalan et al., (2007). Association of physical Activity and Dietary Behaviours in Relation to the Body Mass Index in a National Sample of Iranian Children and Adolescents: CASPIAN Study, Journal of Bull World Health Organ, 85(1), pp.1926. ]

Kelley, et al., (2014)[footnoteRef:13] conduct the study O Effects of Exercise on BMI Z-Score in Overweight and Obese Children and Adolescents: a Systematic Review with Meta-Analysis. Overweight and obesity are major public health problems in children and adolescents. The purpose of this study was to conduct a systematic review with meta-analysis to determine the effects of exercise (aerobic, strength or both) on body mass index (BMI) z-score in overweight and obese children and adolescents. Studies were included if they were randomized controlled exercise intervention trials 4 weeks in overweight and obese children and adolescents 2 to 18 years of age, published in any language between 19902012 and in which data were available for BMI z-score. Studies were retrieved by searching eleven electronic databases, cross-referencing and expert review. Two authors (GAK, KSK) selected and abstracted data. Bias was assessed using the Cochrane Risk of Bias Assessment Instrument. Exercise minus control group changes were calculated from each study and weighted by the inverse of the variance. All results were pooled using a random-effects model with non-overlapping 95% confidence intervals (CI) considered statistically significant. Heterogeneity was assessed using Q andI2while funnel plots and Eggers regression test were used to assess for small-study effects. Influence and cumulative meta-analysis were performed as well as moderator and meta-regression analyses. Of the 4,999 citations reviewed, 835 children and adolescents (456 exercise, 379 control) from 10 studies representing 21 groups (11 exercise, 10 control) were included. On average, exercise took place 4 x week for 43 minutes per session over 16 weeks. Overall, a statistically significant reduction equivalent to 3% was found for BMI z score. No small-study effects were observed and results remained statistically significant when each study was deleted from the model once. Based on cumulative meta-analysis, results have been statistically significant since 2009. None of the moderator or meta-regression analyses were statistically significant. The number-needed-to treat was 107 with an estimated 116,822 obese US children and adolescents and approximately 1 million overweight and obese children and adolescents worldwide Exercise improves BMI z-score in overweight and obese children and adolescents and should be recommended in this population group. However, a need exists for additional studies on this topic. [13: A. George Kelley, et.al,(2014), O Effects of Exercise on BMI Z-Score in Overweight and Obese Children and Adolescents: a Systematic Review with Meta-Analysis, retrieved on 16 Sep 2014 from online website http://www.biomedcentral.com/1471-2431/14/225/abstract]

Lee, et al., (2013)[footnoteRef:14] conduct the study Nutrition, Physical Activity, and Obesity, Centers for Disease Control and Prevention. School-based BMI measurement has attracted attention across the nation as a potential approach to address obesity among youth. However, little is known about its impact or effectiveness in changing obesity rates or related physical activity and dietary behaviors that influence obesity. This article describes current BMI-measurement programs and practices, research, and expert recommendations and provides guidance on implementing such an approach. An extensive search for scientific articles, position statements, and current state legislation related to BMI-measurement programs was conducted. A literature and policy review was written and presented to a panel of experts. This panel, comprising experts in public health, education, school counseling, school medical care, and parenting, reviewed and provided expertise on this article. School-based BMI-measurement programs are conducted for surveillance or screening purposes. Thirteen states are implementing school-based BMI-measurement programs as required by legislation. Few studies exist that assess the utility of these programs in preventing increases in obesity or the effects these programs may have on weight-related knowledge, attitudes, and behaviors of youth and their families. Typically, expert organizations support school-based BMI surveillance; however, controversy exists over screening. BMI screening does not currently meet all of the American Academy of Pediatrics criteria for determining whether screening for specific health conditions should be implemented in schools. Schools initiating BMI-measurement programs should adhere to safeguards to minimize potential harms and maximize benefits, establish a safe and supportive environment for students of all body sizes, and implement science-based strategies to promote physical activity and healthy eating. [14: M. L. Sarah Lee et al., (2013), Nutrition, Physical Activity, and Obesity, Centers for Disease Control and Prevention, retrieved on 16 Sep 2014 from online website http://pediatrics.aappublications.org/content/124/Supplement_1/S89. ]

Skouteris, et al., (2012)[footnoteRef:15] conduct the study Body Mass Index and Dental Caries in Children and Adolescents. A Systematic Review of literature published 2004 to 2011.The authors undertook an updated systematic review of the relationship between body mass index and dental caries in children and adolescents. The authors searched Medline, ISI, Cochrane, Scopus, Global Health and CINAHL databases and conducted lateral searches from reference lists for papers published from 2004 to 2011, inclusive. All empirical papers that tested associations between body mass index and dental caries in child and adolescent populations (aged 0 to 18 years) were included. Dental caries is associated with both high and low body mass index. A non-linear association between body mass index and dental caries may account for inconsistent findings in previous research. We recommend future research investigate the nature of the association between body mass index and dental caries in samples that include a full range of body mass index scores, and explore how factors such as socioeconomic status mediate the association between body mass index and dental caries. [15: Helen Skouteris et al., (2012). Body Mass Index and Dental Caries in Children and Adolescents, retrieved on 16 November 2014 from online website http://www.systematicreviewsjournal.com/content/1/1/57]

Harris, et al., (2012)[footnoteRef:16] conduct the study Effect of School-based Physical Activity Interventions on Body Mass Index in Children: a Meta-Analysis. The prevalence of childhood obesity is increasing at an alarming rate. Many local governments have enacted policies to increase physical activity in schools as a way to combat childhood obesity. We conducted a systematic review and meta-analysis to determine the effect of school-based physical activity interventions on body mass index (BMI) in children. We searched MEDLINE, EMBASE, CINAHL and the Cochrane Central Register of Controlled Trials up to September 2008. We also hand-searched relevant journals and article reference lists. We included randomized controlled trials and controlled clinical trials that had objective data for BMI from before and after the intervention, that involved school-based physical activity interventions and that lasted for a minimum of 6 months. Of 398 potentially relevant articles that we identified, 18 studies involving 18 141 children met the inclusion criteria. The participants were primarily elementary school children. The study duration ranged from 6 months to 3 years. In 15 of these 18 studies, there was some type of co-intervention. Meta-analysis showed that BMI did not improve with physical activity interventions (weighted mean difference 0.05 kg/m2, 95% confidence interval 0.19 to 0.10). We found no consistent changes in other measures of body composition. School-based physical activity interventions did not improve BMI, although they had other beneficial health effects. Current population-based policies that mandate increased physical activity in schools are unlikely to have a significant effect on the increasing prevalence of childhood obesity. [16: C. Kevin Harris, et al., (2012). Effect of School-based Physical Activity Interventions on Body Mass Index in Children: a Meta-Analysis. retrieved on 16 November 2014 from online website http://www.cmaj.ca/content/180/7/719.full]

Verma, et al., (2005)[footnoteRef:17] conduct the study Change in BMI after Mid-foot and Hind-foot Arthrodesis A retrospective review of prospectively collected data. Obesity has become a major public health epidemic, with recent reports citing that 22% of English men and 24% of women are clinically obese. Painful foot and ankle joints are often pointed out as an impending factor for lack of mobility and weight reduction. There is an assumption that weight loss will occur after their surgery due to increased mobility. The current study aimed to evaluate the effect of surgery on post operative body mass index (BMI) in patients who underwent mid-foot or hind-foot arthrodesis. All patients who underwent mid-foot and hind-foot arthrodesis under the care of senior author from April 2005 to Nov. 2006 were identified from the operating theatre records. In total 33 procedures were done in 31 patients. Each patients BMI recorded pre-operatively was compared with that recorded at a minimum of 6 months postoperatively using the paired Students t-test. Analysis of the data was also conducted by stratifying pre-operative BMI, good pain relief (i.e AOFAS>80), sex and fusion site.It was found that there was a mean increase of BMI by 0.25 (95% CI of 0.95 to 0.44) with p-value of 0.47.It was noted that BMI of patients in obese group increased post-operatively by 0.07 (95% confidence interval of 1.52 to 1.66) with p-value of 0.9.This study highlights the fact that there is no significant effect on BMI in obese patients despite significant increase in mobility and pain levels after mid-foot and hind-foot arthrodesis. The change in BMI after fusion surgery is not significantly affected by sex or quality of pain relief. [17: R. Verma et al., (2005) Change in BMI after Mid-Foot and Hind-Foot Arthrodesis, retrieved on 16 November 2014 from online website http://www.bjjprocs.boneandjoint.org.uk/content/92-B/SUPP_IV/591.3.]

Rajib, et al, (2013)[footnoteRef:18] conduct the study Body Mass Index-Mortality Paradox in Hemodialysis. Can It Be Explained by Blood Pressure Unlike the general population, among hemodialysis patients body mass index (BMI) is related to blood pressure (BP) and mortality inversely. To explore the reasons for this risk-factor paradox, the cross-sectional association of obesity with the following factors was examined: the prevalence of hypertension, its control, and echocardiographic left ventricular mass index (LVMI). Longitudinal follow-up explored the relationship of BMI with all-cause mortality. Furthermore, it explored whether poorer survival in leaner individuals was related to either high BP or greater LVMI. Among 368 hemodialysis patients, both the prevalence of hypertension and its poor control were inversely related to BMI. BMI was also inversely associated with evidence of excess extracellular fluid volume, but adjustment for this variable did not completely remove the inverse relationship between BP and BMI. Over 1122 patient-years of cumulative follow-up (median: 2.7 years), 119 patients (32%) died. In the first 2 years of follow-up, the mortality hazard for the lowest BMI group was increased; thereafter, the survival curves were similar. Adjusting for several risk factors including BP and LVMI did not remove the inverse relationship of BMI with mortality. In conclusion, leaner patients on dialysis have a higher prevalence of hypertension, poorer control of hypertension, more LVMI, and greater evidence of extracellular fluid volume excess. However, volume explains the greater prevalence or poorer control of hypertension only partially. Leaner patients have an accelerated mortality rate in the first 2 years; this is not completely explained by BP, LVMI, or other cardiovascular or dialysis-specific risk factors. [18: Rajib Agarwal et al., (2013). Body Mass Index-Mortality Paradox in Hemodialysis, retrieved on 29 December 2014 from online website http://hyper.ahajournals.org/content/58/6/1014.abstract]

Zeller, et al., (2005)[footnoteRef:19] conduct the study The Relationship of Health Outcomes to Improvement in BMI in Children and Adolescents .To evaluate the clinical outcomes of patients participating in an outpatient program for managing childhood and adolescent obesity. Research Methods and Procedures: Based on a retrospective chart review, 394 physician-referred obese youth (BMI > 95th percentile), 5 to 19 years of age, were treated in an interdisciplinary, family-centered, behavioral weight management program in a hospital-based outpatient setting. Treatment included group exercise, parent education, and behavioral intervention therapies to improve diet and physical activity. A total of 177 (45%) completed the initial phase of treatment (mean duration = 5.6 months). For the completion group, there were significant improvements (allp< 0.001) in weight (2.0 4.9 kg), BMI (1.7 1.9 kg/m2), and BMIzscore (0.15 0.15), without interfering with growth (height, 2.2 1.3 cm;p< 0.001). Significant improvement was also found for blood pressure, total cholesterol, low-density lipoprotein (LDL)-cholesterol, triglycerides, insulin, and aerobic fitness. At onset of treatment, 134 (84%) patients had abnormal fasting insulin concentration, 88 (50%) had abnormal total cholesterol, 14 (8%) had abnormal diastolic blood pressure, and 69 (40%) had abnormal LDL-cholesterol. At the end of treatment, a significant proportion of patients with baseline abnormal blood pressure, total cholesterol, and LDL-cholesterol had normal values (p< 0.001). A decrease in BMIzscore was associated with significant improvements in insulin and lipid values (allp< 0.05).We have demonstrated that a modest decrease in BMI in an ongoing clinical pediatric weight management program is accompanied by significant improvements in related health measures. These results may be helpful in counseling families with overweight children and adolescents. [19: M. Zeller et al., (2005). The Relationship of Health Outcomes to Improvement in BMI in Children and Adolescents, International Journal of health out com, Volume 13,Issue 5,pages 876882,]