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Objectives. The study aimed to assess the relationship between body fat and each of body mass index (BMI) and waist circumference (WC), and to test the effectiveness of fat mass (FM), percent of body fat (PBF), BMI, and WC in predicting high levels of fasting blood glucose (FBG). Methods. A total of 167 adolescents aged 11–17 years were recruited from Rabat region. BMI and WC were determined using standard equipments. FM and PBF were derived from isotope dilution technique. FBG was determined by the hexokinase method. Results. Regardless of the weight status, BMI showed a strong positive correlation with FM and PBF in both genders. WC was significantly correlated with FM in boys and girls, and with PBF in different groups of girls and boys of the study sample. However, there was no significant relationship between WC and PBF in normal weight and overweight-obese groups of boys. FBG was highly correlated with FM and PBF in girls of the study sample and in overweight-obese girls. Similar significant relationship between FBG and both BMI and WC was observed in overweight-obese girls, while there was no significant association between FBG and other variables in boys and normal-weight girls. Conclusion. BMI and WC were closely associated with FM and PBF, respectively. However, the degree of these associations depends on gender and weight status. BMI may provide a better proxy estimate of overall adiposity than WC; nevertheless, both of them would appear to be a reasonable surrogate for FM and PBF as screening tools to identify adolescents at risk of developing excess body fat and high level of FBG.

Despite the well-established role of lexis in proficiency in the four skills, a great deal of research has focused on the importance of vocabulary breadth and depth in reading. Therefore, the neglect of productive skills has motivated recent calls to inspect the impact of lexical dimensions on writing ability. Using Partial Least Squares Structural Equation Modelling (PLS SEM), this study examines the contributions of vocabulary breadth and depth aspects to EFL learners’ narrative writing ability. For this purpose, the researchers administered the Updated Vocabulary Levels Test (the UVLT), the Productive Vocabulary Levels Test (the PVLT), the Word Associates Test (the WAT), and a narrative writing task to 77 EFL undergraduate students. The participants’ scripts were scored, following IELTS analytical band descriptors. Results of the PLS SEM disclosed that vocabulary size and depth explained around 45% of the variance in the writing scores of the subjects. They also revealed that, among the variables examined, receptive vocabulary size was the only statistically significant factor that contributed the most to writing ability. The implications for writing assessment and instruction are discussed.

Vitamin A deficiency is a major global public health problem. Among the variety of techniques that are available for assessing human vitamin A status, evaluating the provitamin A nutritional values of foodstuffs and estimating human vitamin A requirements, isotope dilution provides the most accurate estimates. Although the relative expense of isotope dilution restricts its applications, it has an important function as the standard of reference for other techniques. Mathematical modelling plays an indispensable role in the interpretation of isotope dilution data. This review summarises recent applications of stable isotope methodology to determine human vitamin A status, estimate human vitamin A requirements, and calculate the bioconversion and bioefficacy of food carotenoids. [ABSTRACT FROM AUTHOR]