Today, Sight and Life is joining hands with FAO to celebrate World Food Day. This year, in fact, marks the 75th Anniversary of the founding of FAO, and World Food Day 2020 aptly has the theme “Grow, nourish, sustain. Together. Our actions are our future.”
Here at Sight and Life, we have been working for many years on food fortification programs designed to enhance the diet quality of vulnerable populations. In this blog, we take a closer look at how micronutrient deficiencies are measured, and we challenge researchers and policy-makers to re-think current dietary metrics in the face of the Covid-19 pandemic.
Improving the quality of diets worldwide
The latest SOFI report reminds us that access to nutritious food is one of the most pressing issues of our time (2). Globally, the majority of consumed calories are derived from grains (45%), followed by sugars and fats (20%), then fruit and vegetables (11%) (1). These numbers illustrate a recurring situation: people in low-income countries rely on the consumption of staples due to the high cost of fresh and nutritious foods such as fruit, vegetables, and animal-source foods. This is not surprising when we reflect that healthy and diverse diets are five times more expensive than staple-based diets (2).
The current pandemic has intensified an already unacceptable situation by compromising access to school feeding programs, disrupting nutritious food value chains, and further reducing the purchasing power of consumers. Food fortification is a recognized and cost-effective approach to improve the nutritional status of populations in both high-income and low-income countries. It benefits especially those who rely on a staple-based diet that is generally poor in essential micronutrients.
When access to nutritious foods is limited, the fortification of staple foods can help ensure an adequate intake of essential micronutrients. Moreover, fortified foods help support the body’s immune defenses against infections (3) (read more: the role of nutrition in the immune system). In short, food fortification enhances dietary diversity, a key element of diet quality, and has important health benefits too.
Dietary diversity: What is it and how do we measure it?
Dietary diversity was found to serve as a proxy indicator to assess and predict the intake of micronutrients (4,5,6). To easily assess the dietary diversity of a population, a practical tool was developed: the Dietary Diversity Score (DDS) (7). The score reflects the number of different (and pre-defined) food groups that have been consumed by a sample of the population during the previous 24 hours, as described by Krebs et al in 1987. The score is calculated by summing up the number of food groups consumed.
Today, the DDS has been differentiated according to the intended target groups and counts up to 12 food groups, depending on the target group of the score (Figure 1). In both the DDS for women and the DDS for children, we find a differentiation for some specific fruits and vegetables to adequately reflect their specific micronutrient composition. Globally, less than one in three children aged 6–23 months (29%) were found to consume five out of eight pre-defined food groups and thus meet the minimum dietary diversity (MDD) (2). The percentage of children meeting the MDD varies greatly across the globe. In Burkina Faso and Guinea respectively, for example, only 5.2% and 5.9% of children received the MDD, whereas in Turkmenistan and Peru respectively, 82.5% and 82.9% of children met the MDD score (8). The MDD-W (W = women) was included as a core indicator in the Demographic and Health Survey (DHS) in 2019. To date, three countries have published data (2). The available data indicate poor dietary diversity and consequent micronutrient inadequacy.
Overall, the advantage of DDS indicators is the ease with which the data can be collected, analyzed and interpreted. DDS is a practical tool for use in resource-poor settings, and its results can easily be communicated. The most remarkable limitation of DDS, however, is the fact that it does not reflect the intake of fortified food.
Even more astonishing is the fact that the DDS guideline strongly recommends documenting the consumption of these foods (9). The extent to which we can accurately predict micronutrient adequacy in populations with a diet based on cereals and/or other staples, which are often fortified, is still entirely unknown.
Figure 1: Food group classification for different dietary diversity scores