Association between Physical Activity and Health Outcomes (High Body Fatness, High Blood Pressure) in Namibian Adolescents and Adult women.

Regular physical activity (PA) is known to promote the physical and mental health of children and adolescents and further prevent the development of health problems in adulthood. Information on body composition and PA is crucial for health promotion strategies and for epidemiological studies informing policies. However, there is limited data on the association between body composition and PA in Namibia. This dearth of published data is a significant shortcoming in the development of strategies and policies to promote PA in Namibia. Therefore, this cross-sectional study was conducted to determine the association between PA as a dependent variable and independent variables such as high blood pressure and body fatness as measured by different methods (gold standard deuterium dilution, body mass index, mid upper arm circumference, and waist circumference). The study included 206 healthy adolescent girls aged 13-19 years and 207 young adult females aged 20-40 years from Windhoek, Namibia. PA was measured using the PACE+ questionnaire in adolescents, and the GPAQ questionnaire was used for adults. In adolescents, only 33% of the participants met the recommended guidelines for PA, compared to only 2% for adults. Nevertheless, the study found no statistically significant association between PA and blood pressure indices (p-value < 0.05) among adolescents and adults. However, there was a significant association between PA and high body fatness (p-value < 0.001) and waist circumference (p-value = 0.014) in adolescents. Among adults, PA was significantly related to waist circumference only. In conclusion, failure to meet recommended PA guidelines is strongly associated with abdominal obesity and high body fatness. The knowledge gained from this study may be used by policymakers in the development of strategic policies and interventions aimed at promoting PA as a public priority and improving health outcomes.

Body mass index vs deuterium dilution method for establishing childhood obesity prevalence, Ghana, Kenya, Mauritius, Morocco, Namibia, Senegal, Tunisia and United Republic of Tanzania.

OBJECTIVE: To compare the World Health Organization (WHO) body mass index (BMI)-for-age definition of obesity against measured body fatness in African children. METHODS: In a prospective multicentre study over 2013 to 2017, we recruited 1516 participants aged 8 to 11 years old from urban areas of eight countries (Ghana, Kenya, Mauritius, Morocco, Namibia, Senegal, Tunisia and United Republic of Tanzania). We measured height and weight and calculated BMI-for-age using WHO standards. We measured body fatness using the deuterium dilution method and defined excessive body fat percentage as > 25% in boys and > 30% in girls. We calculated the sensitivity and specificity of BMI z-score > +2.00 standard deviations (SD) and used receiver operating characteristic analysis and the Youden index to determine the optimal BMI z-score cut-off for classifying excessive fatness. FINDINGS: The prevalence of excessive fatness was over three times higher than BMI-for-age-defined obesity: 29.1% (95% CI: 26.8 to 31.4; 441 children) versus 8.8% (95% CI: 7.5 to 10.4; 134 children). The sensitivity of BMI z-score > +2.00 SD was low (29.7%, 95% CI: 25.5 to 34.2) and specificity was high (99.7%, 95% CI: 99.2 to 99.9). The receiver operating characteristic analysis found that a BMI z-score +0.58 SD would optimize sensitivity, and at this cut-off the area under the curve was 0.86, sensitivity 71.9% (95% CI: 67.4 to 76.0) and specificity 91.1% (95% CI: 89.2 to 92.7). CONCLUSION: While BMI remains a practical tool for obesity surveillance, it underestimates excessive fatness and this should be considered when planning future African responses to the childhood obesity pandemic.

Inventory on the dietary assessment tools available and needed in africa: a prerequisite for setting up a common methodological research infrastructure for nutritional surveillance, research, and prevention of diet-related non-communicable diseases.

OBJECTIVE: To carry out an inventory on the availability, challenges, and needs of dietary assessment (DA) methods in Africa as a pre-requisite to provide evidence, and set directions (strategies) for implementing common dietary methods and support web-research infrastructure across countries. METHODS: The inventory was performed within the framework of the "Africa's Study on Physical Activity and Dietary Assessment Methods" (AS-PADAM) project. It involves international institutional and African networks. An inventory questionnaire was developed and disseminated through the networks. Eighteen countries responded to the dietary inventory questionnaire. RESULTS: Various DA tools were reported in Africa; 24-Hour Dietary Recall and Food Frequency Questionnaire were the most commonly used tools. Few tools were validated and tested for reliability. Face-to-face interview was the common method of administration. No computerized software or other new (web) technologies were reported. No tools were standardized across countries. CONCLUSIONS: The lack of comparable DA methods across represented countries is a major obstacle to implement comprehensive and joint nutrition-related programmes for surveillance, programme evaluation, research, and prevention. There is a need to develop new or adapt existing DA methods across countries by employing related research infrastructure that has been validated and standardized in other settings, with the view to standardizing methods for wider use.