The relationship between physical activity & body mass index

Physical Activity and Its Association With Body Mass Index: A Cross-Sectional Analysis in Middle-Aged Adults from 4 Sub-Saharan African Countries

Monica Muti

The purpose of this study was to investigate the relationship between self-reported physical activity (PA) domains (i.e., work, leisure, and transport-related PA) and body mass index (BMI) in 9388 men and women aged 29-82 years. These participants were recruited across five sites in Africa as part of the Africa-Wits-INDEPTH partnership for Genomic (AWI-Gen) study. Face-to-face interviews were conducted at study sites in various countries to collect data on PA and demographic variables.

The study also found regional and sex-specific variations in patterns of PA when assessing activity in work, travel, and leisure domains, as well as their association with BMI, across five communities in four African countries. Although the prevalence of meeting PA recommendations was high (above 80%) in both men and women, it was higher in men (83.9% vs 80.5%). Work and transportation-related PA contributed the most to total moderate to vigorous physical activities (MVPA), with leisure time PA contributing very little at these sites. These findings correspond to those previously reported in low-income settings.

A comparison of domain-specific PA patterns in 104 countries revealed that low-income countries had more work and transportation-related PA than high-income countries. In Africa, for example, work frequently involves manual labour, which may result in higher work and transportation-related PA. It’s also possible that a sizable proportion of the participants will find transportation costs prohibitively expensive. As a result, they choose to walk or take other nonmotorized transportation to work, which is consistent with findings from an earlier study in Nairobi, where walking or taking other nonmotorized transportation was the primary mode of transportation.

Results indicate that BMI differs greatly between locations and between sexes and that PA may not be enough to lower BMI on its own. Therefore, the paper contends, there is a requirement for more context-specific PA recommendations. https://doi.org/10.1123/jpah.2022-0539

Dietary habits and overall adiposity in black South African adolescents and adults

Nutrient Patterns and Body Mass Index: A Comparative Longitudinal Analysis in Urban Black South African Adolescents and Adults

The purpose of this study was to assess the relationship between dietary habits and overall adiposity in black South African adolescents and adults and to ascertain if the relationships are longitudinally sustained over a 24-month period.

The research was carried out at the Chris Hani Baragwanath Academic Hospital (CHBAH) in Soweto’s SAMRC/Wits Developmental Pathways for Health Research Unit (DPHRU).

The nutritional patterns of 750 participants—250 teenagers between the ages of 13 and 17 and 500 adults between the ages of 27 and 45—were determined using principal component analysis (PCA).

According to the author’s knowledge, no research has examined the relationship between dietary habits and BMI over time in black South African adolescents and adults.

The authors found that the dietary habits of adults and adolescents were similar throughout time, however, their correlations with BMI were different. Only the “plant-driven nutrition pattern” was significantly and positively linked to an increase in adolescents’ BMI. The “plant-driven nutrient pattern” and the “fat-driven nutrient pattern” were both significantly and positively associated with an increase in BMI in adults.

Furthermore, the findings that adults mostly consumed plant-based nutrients are consistent with those reported by Ratshikombo et al. and Makura-Kankwende et al. among middle-aged Black South Africans. In contrast, the findings that both genders of urban adolescents consume a diet that is primarily plant-based contradicts previous findings by Pisa et al., in which the authors reported that adolescents in rural areas consumed the most “animal-derived nutrients” (e.g., dairy products, fish, eggs etc,). The discrepancies between the current findings and those of Pisa et al. among adolescents might be explained by a rapid change in nutrition transition occurring in rural regions. This change is characterised by higher intakes of animal protein, fat, and added sugar, indicating a shift to a more “Western” diet. This transition is often accompanied by reduced levels of physical activity, particularly among teenage girls.

These findings suggest that adolescents’ eating habits are influenced by their geographic location (for example, urban versus rural) and socioeconomic status. Therefore, programs aimed at encouraging youth to eat healthier diets should take these factors into account before being implemented.

In conclusion, while there are changes in age and gender in the connection of nutrient patterns with BMI, their stability across time suggests that dietary interventions aiming at improving health outcomes can start earlier, in adolescence. The findings have implications for future attempts to promote preconception health through nutrition as they emphasize the importance of taking gender variations into consideration and addressing both girls’ and boys’ health-related behaviors.

https://doi.org/10.3390/nu15051075