Assessing Diet Quality Where Families Share Their Meals: Evidence from Malawi

Where families eat together from a common dish, the shared meal must be nutrient dense enough in each nutrient to meet the needs of the highest-need member.

This study aimed to develop an aggregate household nutrient requirement benchmark that satisfies all members' needs in a context in which meals are shared and to illustrate how that metric could inform food and nutrition policy making.

We merged nationally representative survey data for Malawi in 2010, 2013, and 2016-2017 with individual nutrient requirements and local food composition data to compute the adequacy of each household's aggregate consumption given its demographic composition and primary occupation. To meet each person's nutrient needs at any level of energy balance, the nutrient density of their shared diet needs to be within boundaries of the most restrictive member. We classified the adequacy of each household's diet using these energy-adjusted densities and examined differences by sociodemographic characteristics.

Accounting for meal sharing and nutrient density needs of the highest-need member, virtually all households' food consumption is insufficiently nutrient dense in riboflavin, selenium, lipids, and vitamin B-12, and most consumption is insufficiently nutrient dense in zinc and phosphorus as well. Meeting needs of women, adolescent girls, and young children using shared diets would on average require 145% more iron, 98% more zinc, and approximately 70% more phosphorus and vitamin C than if their needs were met with individualized diets.

Establishing shared nutrient requirements is feasible using existing survey data and can help set sufficiency criteria in settings in which families share meals. In Malawi, current diets and food composition are inadequate for many nutrients, especially in households with more women and adolescent girls. The results call for concerted investment to increase access to and use of more nutrient-dense foods.