Hala Youssef

Activity, inactivity and quality of life among Lebanese adolescents

Background:  The aim of the present study was to investigate recent overweight and obesity prevalence rates for Lebanese adolescents, and to examine differences in physical activity, screen time (sum of time spent in front of TV, computer, and videogames), and health‐related quality of life (HRQOL) for the first time among normal, overweight, and obese adolescents.

Nutritional and Plasmatic Antioxidant Vitamins Status of Ultra Endurance Athletes

Objective: The “Marathon des Sables” (MDS) is a competition known to induce oxidative stress. Antioxidant vitamins prevent exercise-induced oxidative damages. The purpose of this study was to evaluate daily intake and plasma level of the main antioxidant vitamins (α-tocopherol, vitamin C, β-carotene and retinol) in 19 male athletes who participated in this competition. Methods: Data collected before the beginning of the competition included daily dietary intake using a 7-day food record and plasma biochemical measurements (α-tocopherol, vitamin C, β-carotene and retinol). Results: First, total energy intake was obviously lower than the energetic intake usually observed in well-trained endurance athletes. Second, antioxidant vitamins intake was also insufficient. Indeed, the intake was lower than the French Dietary Reference Intakes (DRI) for this population in 18 subjects for vitamin E and 6 subjects for vitamin C, β-carotene and Retinol Equivalent. As a significant relationship was found between total energy intake and the intake of vitamin E (r = 0.73; p < 0.001) and vitamin C (r = 0.78; p < 0.001), the low total energy intake contributed partially to the insufficient antioxidant vitamins intake. The dietary questionnaire analysis also revealed a low intake of vegetable oils, fruits and vegetables. However, plasma concentrations of these antioxidant vitamins were similar to the literature data observed in athletes. Conclusion: This study evidenced obvious insufficient energy intake in ultra endurance athletes associated with a low antioxidant vitamin intake.

Exercise-induced oxidative stress in overweight adolescent girls: roles of basal insulin resistance and inflammation and oxygen overconsumption

Hypothesis:Basal insulin resistance (IR) and inflammation exacerbate post-exercise oxidative stress (OS) in overweight adolescent girls.Design:Cross-sectional study, effect of incremental ergocycle exercise until exhaustion on OS markers.Participants:Normal-weight (control) (n=17, body mass index (BMI): 20–24.2 kg/m2) and overweight adolescent girls (n=29, BMI: 24.1–36.6 kg/m2).Measurements:Dietary measurement, physical activity assessment (validated questionnaires), fat distribution parameters (by dual-energy X-ray absorptiometry and anthropometry) and maximal oxygen consumption ([Vdot ]O2peak). Blood assays include the following: (1) at fasting state: blood cell count, lipid profile, and IR parameters (leptin/adiponectin ratio (L/A), homeostasis model assessment of IR, insulin/glucose ratio; (2) before exercise: inflammation and OS markers (interleukin-6 (IL-6), C-reactive protein (CRP), myeloperoxidase (MPO), reduced glutathione/oxidized glutathione ratio (GSH/GSSG), 15 F2α-isoprostanes (F2-Isop), lipid hydroperoxides (ROOH), oxidized low-density lipoprotein (ox-LDL)) and antioxidant status (superoxide dismutase (SOD), glutathione peroxidase (GPX), vitamin C, α-tocopherol and β-carotene); and (3) after exercise: inflammation and OS markers.Results:At rest, overweight girls had a deteriorated lipid profile and significantly higher values of IR parameters and inflammation markers, compared with the control girls. These alterations were associated with a moderate rest OS state (lower GSH/GSSG ratio, α-tocopherol/total cholesterol (TC) ratio and GPX activity). In absolute values, overweight girls exhibited higher peak power output and oxygen consumption ([Vdot ]O2peak), compared with the control girls. Exercise exacerbated OS only in the overweight group (significant increase in F2-Isop, ROOH and MPO). As hypothesized, basal IR and inflammation state were correlated with the post-exercise OS. However, the adjustment of F2-Isop, ROOH and MPO variation per exercise [Vdot ]O2 variation canceled the intergroup differences.Conclusion:In overweight adolescent girls, the main factors of OS, after incremental exhaustive exercise, are not the basal IR and inflammation states, but oxygen overconsumption.

Aerobic Training Suppresses Exercise-induced Lipid Peroxidation and Inflammation in Overweight/Obese Adolescent Girls

This study aimed to determine whether aerobic training could reduce lipid peroxidation and inflammation at rest and after maximal exhaustive exercise in overweight/obese adolescent girls. Thirty-nine adolescent girls (14-19 years old) were classified as nonobese or overweight/obese and then randomly assigned to either the nontrained or trained group (12-week multivariate aerobic training program). Measurements at the beginning of the experiment and at 3 months consisted of body composition, aerobic fitness (VO2peak) and the following blood assays: pre- and postexercise lipid peroxidation (15F2a-isoprostanes [F2-Isop], lipid hydroperoxide [ROOH], oxidized LDL [ox-LDL]) and inflammation (myeloperoxidase [MPO]) markers. In the overweight/ obese group, the training program significantly increased their fat-free mass (FFM) and decreased their percentage of fat mass (%FM) and hip circumference but did not modify their VO2peak. Conversely, in the nontrained overweight/obese group, weight and %FM increased, and VO2peak decreased, during the same period. Training also prevented exercise-induced lipid peroxidation and/or inflammation in overweight/obese girls (F2-Isop, ROOH, ox-LDL, MPO). In addition, in the trained overweight/obese group, exercise-induced changes in ROOH, ox-LDL and F2-Isop were correlated with improvements in anthropometric parameters (waist-to-hip ratio, %FM and FFM). In conclusion aerobic training increased tolerance to exercise-induced oxidative stress in overweight/obese adolescent girls partly as a result of improved body composition.

Overweight and Obesity Related Factors among Lebanese Adolescents: AnExplanation for Gender and Socioeconomic Differences

Background: The obesity-related factors in adolescents differ from one country to another. In Lebanon, those factors are still undetermined. Therefore, our purpose is to investigate the main determinants of overweight and obesity in Lebanese adolescents and to assess gender-specific differences. Methods: In this cross-sectional epidemiological study, 1000 Lebanese adolescents were recruited to determine obesity-related factors: birth weight, weight at 5 and 10-year-old children, feeding pattern, only child or first born status, puberty characteristics, lifestyle [nutrition, sedentary behaviors, and physical activity], school grades, family obesity, obesity-related diseases, place of residence, and socio-economic and professional status of parents. Results: Multiple regressions show that puberty obesity, lifestyle, family obesity and family status, and childhood feeding pattern are consecutively the major factors to adolescents’ obesity. Contrary to Western countries, overweight and obese Lebanese adolescents belong to a high socioeconomic class, and they do practice more physical and leisure activities. This paradox is more obvious in boys (having a higher socio-economic status compared to girls, boys are more affected by overweight and obesity caused by behavioral problems and this despite their more frequent physical leisure activities). On the contrary, girls’ obesity is more associated with family obesity rather than behavior disorders. Conclusion: Lebanese adolescents’ obesity is related to many behavior disorders especially in boys. Moreover, their physical practice is not sufficient to overcome their excessive sedentary behaviors and nutritional mistakes.