Conductas alimentarias de riesgo, interiorización del ideal estético de delgadez e índice de masa corporal en estudiantes hidalguenses de preparatoria y licenciatura de una institución privada / Disordered eating, internalization of the body thin-ideal and body mass index in high school and college students from a private institution in Hidalgo, Mexico

ABSTRACT

The term <<eating behavior>> is immediately related to food consumption. However, eating is a complex behavior mediated by external factors. Eating is not exclusively related to satisfying individual's needs or nutritional requirements. Eating behavior alteration has originated disordered eating (DE) and eating disorders (ED), such as anorexia nervosa, bulimia nervosa and binge eating syndrome, where patterns of food ingestion are altered and people forget the importance of maintaining a balance between caloric ingestion and caloric expenditure, with repercussions in the nutritional status and in the individual's health. Recent studies carried out in Mexican population have confirmed the presence of DE, particularly among adolescents and young adults, and predominantly in females. Data from a representative sample of students with a mean age of 14.5 years reported an increase in the proportion of DE between the 1997 and the 2003 assessments (1.3% in males and 3.4% in females) compared to the 3.8% in males and 9.6% in females registered in 2003. More recent data from the National Nutrition and Health Survey 2006, in a representative sample of adolescents 10 to 19 years of age, indicated a prevalence of 0.8% (1% in females and 0.4% in males), with higher scores in the north and center-west areas of the country, followed by the central and south-south-east areas, with almost two-fold percentages in the urban settings compared to the rural ones. The multifactorial origin of ED is well known and among the most studied risk factors are eating behaviors, high body mass index (BMI) and body thin-ideal internalization. Research findings indicate that overweight and obese adolescents are at more risk for body dissatisfaction, as their physical appearance is farther away from being as the one promoted by society and the media. The sociocultural pressure to be thin has promoted the internalization of the idea that being thin is synonymous to success, greater social acceptance, femininity (among females), self-control, and self-esteem. Based on the above, the main purpose of this paper was to evaluate the prevalence of DE and its relationship to body thin-ideal internalization and BMI in high school and college male and female students from an urban setting. An additional objective was to provide data on reliability and validity of the scales used in a sample of males, as well as additional validity data in females. Data analyzed in this research come from a larger study on risky factors associated to ED carried out in high-school and college students in the city of Pachuca, Hidalgo, during the 2007-2008 school years. After censing the school, a sample of 845 students was selected (381 males, 464 females), 45.1% was from high school, with a range of 15 to 17 years(× =15.82; D.E.=0.78), and 54.9% from college with a range of 18 to 23 years(× =19.81; D.E.=1.41) and that completed the questionnaires adequately. Two previously validated questionnaires in Mexican samples were used to assess DE and body thin-ideal internalization the Brief Questionnaire for Risky Eating Behaviors and the Attitudes toward Body Figure Questionnaire. Cutoff points for these questionnaires were used to determine the prevalence rates. BMI was obtained by measuring each subject's weight and height by standardized experts and divided in categories according to NCHS those under 18 years old, and to the World Health Organization Experts Committee for those above 18. Self-reported questionnaires were applied to students after verbal consent was received from the school authorities and students, who were previously informed about the voluntary, anonymous, and confidential nature in the study. The protocol was revised by the Ethics Committee of the institution were the field work was carried out. Descriptive analyses were held, as well as Student t tests for comparisons between groups, and a logistic regression analysis to estimate the risk for DE. Results showed that 70% of the women had a normal weight, and there were fewer students in the very underweight and underweight categories (high-school 2.9% and 8.7% college) than those in the overweight and obese categories (high-school 15.2% and 8.3% vs. 18.6% and 6.6% in college). Among the males, a similar distribution was found, 71.3% of the high-school and 58.2% of college students have normal weight, 2.7% and 4.8% low weight, 19.1% and 26.1% were overweight, and 6.9% and 10.9% were obese, respectively. The prevalence of DE was 8.4% in females (9.0% in high school and 7.9% in college), and 2.9% in males (1.6% in high school and 4.2% in college). DE was more prevalent among females, with the exception of binge eating and lack of control while eating. The analysis by BMI showed that neither females nor males with very low or low weight scored high on DE. The higher percentages were obtained for the overweight students of both sexes, and obese males obtained the higher percentages of all. From the total of females with DE, the 84.2% of high-school and 80% of college students also scored high on body thin-ideal internalization, while in males the results were 33.3% and 62.5%, respectively. The regression analysis indicated that the two variables associated with DE were body thin-ideal internalization (OR=27.27) and sex <female>> (OR=2.33). The model correctly classified 94.5% of the cases and explained 35% of the DE occurrence. The DE scale yielded a reliability score of 0.72 in females and of 0.63 in males. For both males and females, the scale yielded 3 factors with a congruent conceptual structure. The Attitudes toward Body Figure Questionnaire had a reliability of 0.94 in females and of 0.89 in males. In the case of females, the structure obtained nearly replicated the one obtained in Mexico City's students, but in the case of the male's questionnaire, three questions were eliminated leaving a two-factor structure. From the present data, it can be concluded that DE is present in the sample studied, mainly in females. It was also found that the preoccupation with gaining weight, dieting, and excessive exercising with the purpose of losing weight are also present in a high percentages in Mexican youths not only from the largest metropolis, but also in other urban settings such as Pachuca, Hidalgo. The prevalence found was similar to the one from the Student Survey from Mexico City in adolescents. A positive relationship between DE, educational status, and age was also found; overweight women and obese men were the ones that obtained the higher percentages of DE. The fact that obese men displayed the higher percentages is an important finding regarding the development of future preventive interventions, as it has been so far a neglected population in relation to this topic. The psychometric properties of the validated questionnaires in females were adequate and factorial structures were conceptually congruent. Nevertheless, in the case of males, it is important to continue working in the development of screening questionnaires sensible to their conceptions, beliefs, and attitudes regarding eating, weight control, and beauty ideal, in a way to count with reliable and valid instruments for the detection of DE and body thin-ideal internalization, so we recommend to use caution in interpreting the use of these scales in male populations.

RESUMEN

El término <<conducta alimentaria>> se asocia de manera inmediata con el hecho de ingerir alimentos; sin embargo, es una conducta compleja mediada por factores externos a la persona y no exclusivamente porque los individuos quieran satisfacer sus necesidades alimentarias y sus requerimientos nutricios. La alteración de esta conducta ha dado origen a lo que se conoce como trastornos de la conducta alimentaria (TCA) tales como la anorexia nervosa, la bulimia nervosa y <trastorno por atracón>>, en los cuales se ven distorsionados los patrones de la ingestión de alimentos, olvidándose la importancia de mantener un balance entre ingestión y gasto de energía, lo que repercute de manera importante en el estado nutricio y por ende en la salud del individuo. Es bien sabido el origen multifactorial de los TCA, y dentro de los factores de riesgo más estudiados están las conductas alimentarias, el Índice de Masa Corporal (IMC) y las actitudes hacia el cuerpo provenientes de la interiorización de una figura corporal delgada. El objetivo principal de este estudio fue conocer la prevalencia de las conductas alimentarias de riesgo (CAR) y su relación con la interiorización del ideal estético de delgadez y con el IMC, en estudiantes de ambos sexos de nivel preparatoria y licenciatura en una escuela privada de la ciudad de Pachuca, Hidalgo. Un objetivo adicional fue el de proporcionar datos de confiabilidad y validez de las escalas utilizadas en una muestra de hombres, así como datos adicionales de validez en las mujeres. Se trabajó con una muestra de 845 sujetos (381 hombres y 464 mujeres) de los cuales 45.1% eran de nivel preparatoria con un rango de edad de 15 a 17 años (× =15.82; D.E.=.78) y 54.9% de nivel licenciatura en un rango de edad de 18 a 23 años (× =19.81; D.E.=1.41). Se aplicaron el Cuestionario Breve de Conductas Alimentarias (CBCAR) y el Cuestionario de Actitudes hacia la Figura Corpora l. El IMC se obtuvo partir de la medición del peso y la estatura de cada sujeto. La distribución por categorías del IMC por nivel escolar mostró que el 70% de las mujeres tiene peso normal, y que el porcentaje de las que se encuentran en las categorías de peso muy bajo y bajo (preparatoria 2.9% y licenciatura 8.7%) es mucho menor que las que se hallan en sobrepeso y obesidad (preparatoria 15.2% y 8.3% vs. licenciatura 18.6% y 6.6%). En los hombres se encontró una distribución similar 71.3% de los de preparatoria y 58.2% de los de licenciatura tienen peso normal, 2.7% y 4.8% bajo peso, 19.1% y 26.1% sobrepeso, y 6.9% y 10.9% obesidad, respectivamente. La prevalencia de CAR en mujeres fue de 8.4% (9.0% en preparatoria; 7.9% en licenciatura) y de 2.9% en hombres (1.6% en preparatoria; 4.2% en licenciatura). <sensación de falta de control al comer, vómito auto-inducido, ayunos, dietas, pastillas, diuréticos y laxantes fueron mayores en las mujeres>>. Del total de mujeres con CAR elevadas, el 84.2% de preparatoria y el 80% de licenciatura también obtuvo puntuaciones altas en el cuestionario sobre interiorización del ideal estético de delgadez, en tanto que en los hombres fue el 33.3% y el 62.5%, respectivamente. La escala CBCAR en mujeres arrojó un alfa de Cronbach de 0.72 y de 0.63 en hombres. El instrumento de actitudes alcanzó valores de confiabilidad de 0.94 para mujeres y de 0.89 para hombres. Se puede concluir que en la población estudiada están presentes las CAR características de los TCA, y que a mayor interiorización de una figura delgada mayor aparición de dichas conductas, principalmente entre las mujeres. Igualmente se comprobó que la práctica de dietas y de ejercicio para bajar de peso, aunadas a la preocupación por engordar, se presentan en porcentajes importantes en estudiantes del Estado de Hidalgo, lo que confirma que esta problemática no es exclusiva de las grandes urbes.