**1. Introduction**

Public health nutrition focuses on promotion and improvement of optimal health of a population through nutrition-related health dietary guidelines and policies. In the sub-Saharan African region, public health challenges such as the increasing burden of malnutrition, diabetes mellitus and cardiovascular diseases, can potentially be addressed with adequate nutrition interventions [1,2]. However, to implement effective nutritional interventions in the region, the nutritional situation of the targeted population needs to be known. This requires reliable food consumption data.

Food composition databases (FCDBs) are essential to public health nutrition and associations between diet and health have been shown at the levels of dietary patterns, food groups, foods, and nutrients [3]. They are used together with dietary intake studies to

**Citation:** Balakrishna, Y.; Manda, S.; Mwambi, H.; van Graan, A. Identifying Nutrient Patterns in South African Foods to Support National Nutrition Guidelines and Policies. *Nutrients* **2021**, *13*, 3194. https://doi.org/10.3390/nu13093194

Academic Editors: Massimo Lucarini and Alessandra Durazzo

Received: 19 August 2021 Accepted: 11 September 2021 Published: 14 September 2021

**Publisher's Note:** MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations.

**Copyright:** © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).

develop food frequency questionnaires and assess relationships between diet and disease. FCDBs also provide insight into food groups and foods containing low or high nutrient levels. Once these relationships have been determined, food-based dietary guidelines (FBDGs) and nutrition policies can be implemented. FBDGs translate recommended dietary allowances to food-related guidelines for improved public health nutrition and guidance [4]. South Africa first developed the FBDGs in 2003 and revised the guidelines in 2012. The South African FBDGs have since been adopted by the National Department of Health as the 'official' dietary recommendations for the country in people aged 5 years or older [4]. The eleven guidelines aim to promote a change in the dietary habits of South Africans to address nutrition-related public health diseases such as malnutrition and obesity. The guidelines encourage dietary diversity and highlight foods that should be limited such as fats, sugar, and salt. Other public health nutrition measures to improve health such as food fortification [5], salt regulations [6] and taxes on sugar-sweetened beverages [7], have also been implemented in South Africa.

Fruits, vegetables, legumes, dairy, and meat are just a few of the common food groups found in FCDBs and accepted by nutritionists. Food items within these food groups generally provide similar amounts of macronutrients. However, while nutritional composition may be similar within these groupings, subgroups may be identifiable and compositional similarity may also be found across these groupings. The growing number of food items in FCDBs presents consumers with dietary choices that need to be based on nutrition, availability, cost, and preference. Classifying food items into nutritionally homogenous groups allows consumers to select alternative food items whilst maintaining a similar nutritional intake. Identifying compositionally similar food items guides dietary recommendations, assists in consumer education, and informs product reformulation. With the ever-expanding food market and inclusion of country-specific foods, it can also aid the categorization of a new food item by grouping it with similar foods that are already known [3]. The identification of unhealthy food items that may not be immediately apparent, also becomes possible.

Several studies have investigated the clustering of food items [8–12] and nutrient co-occurrence patterns [13,14] using statistical methods, but only one was found to use data from Africa [15]. More specifically, the study of nutrient patterns in South Africa has been limited to consumption data [16–19]. Thus, there is a need to develop capacity in methods applicable to the African scenario to help inform consumers and public health policy makers in food nutrient patterns and composition.

Using statistical methods, this study aims to identify compositionally similar food items and nutrient co-occurrence patterns within the South African Food Composition Database (SAFCDB) [20]. The results of this study will provide data-driven evidence that may support the current dietary guidelines and nutritional policies or offer an alternative view.
