Nutrients 2023, 15, 1075. https://doi.org/10.3390/nu15051075 www.mdpi.com/journal/nutrients Article Nutrient Patterns and Body Mass Index: A Comparative Longitudinal Analysis in Urban Black South African Adolescents and Adults Gudani Mukoma 1, *, Shane A Norris 1,2 and Tinashe Chikowore 1 1 SAMRC/Wits Developmental Pathways for Health Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 1862, South Africa 2 School of Human Development and Health, Faculty of Medicine, University of Southampton, Southampton SO17 1BJ, UK * Correspondence: gudani.mukoma@wits.ac.za; Tel.: +27-799037819 Abstract: Objective: We set out to evaluate the association between nutrient patterns and general adiposity in black South African adolescents and adults and to determine whether the interactions are longitudinally sustained over 24 months. Methods: Principal Component Analysis (PCA) was used to derive the nutrient patterns of 750 participants (250 adolescents between 13 and 17 years old and 500 adults who were 27 years or 45 + years old). PCA was applied to 25 nutrients, computed from the quantified food frequency questionnaire (QFFQ) over a 24 months period. Results: The nutrient patterns between adolescents and adults were similar over time; however, their associa- tions with BMI were different. Among the adolescents, only the “plant-driven nutrients pattern” was significantly associated with a 0.56% (95% CI (0.33; 0.78); p < 0.001) increase in BMI. Among the adults, the “plant-driven nutrient pattern” (0.43% (95% CI (0.03; 0.85); p < 0.001) and the “fat-driven nutrients pattern” (0.18% (95% CI (0.06; 0.29); p < 0.001) were significantly associated with a BMI increase. Furthermore, the “plant-driven nutrient pattern”, “fat-driven nutrient pattern” and the animal--driven nutrient pattern revealed sex differences in their association with BMI. Conclusion: Urban adolescents and adults had consistent nutrient patterns, but their BMI relationships changed with age and gender, an important finding for future nutrition interventions. Keywords: BMI; obesity; nutrient patterns; plant protein and fats; PCA 1. Introduction Obesity is a global epidemic [1,2]. Obese people have a greater likelihood of dying from NCDs such as diabetes and heart disease [3–5]. In 2016, 13% of adults (18 years and older) worldwide were obese (11% men, 15% women) [6]. Recent studies suggest that over 70% of the world’s obese population live in developing countries [7]. South Africa now leads Sub-Saharan Africa in obesity prevalence [2,4]. Women (68%) are more likely to be overweight or obese than men (31%) [8]. South African adolescents are also becoming overweight or obese (9% of boys and 27% of girls), similar to several high-income coun- tries [8,9]. This combined prevalence has increased from age 11 to 46.5% in the 21+ age group in South African urban settings, indicating that adolescent NCD risk is rising rap- idly [10]. Thus, more research is needed to understand the alarming rise in obesity rates and why more women than men are affected [11]. Obesity is linked to a sedentary lifestyle, poor diet, low physical activity and insuffi- cient sleep [12]. South Africans of all ages exercise less due to economic changes and ur- banisation [13–15]. Adults with higher SES have lower PA and a higher BMI [16,17]. The ongoing nutritional transition has led to more people eating westernised foods (meat, fats and oils, sauces, dressings, condiments, sweets and soft drinks) [5]. This diet increases the Citation: Mukoma, G.; Norris, SA.; Chikowore, T. Nutrient Patterns and Body Mass Index: A Comparative Longitudinal Analysis in Urban Black South African Adolescents and Adults. Nutrients 2023, 15, 1075. https://doi.org/10.3390/nu15051075 Academic Editor: Brad Schoenfeld Received: 26 January 2023 Revised: 13 February 2023 Accepted: 17 February 2023 Published: 21 February 2023 Copyright: © 2023 by the authors. Li- censee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and con- ditions of the Creative Commons At- tribution (CC BY) license (https://cre- ativecommons.org/licenses/by/4.0/).