Dietary Modification

Dietary modifications are changes made during food preparation, processing, and consumption to increase the bioavailability of micronutrients—and reduce micronutrient deficiencies—in food at the commercial or individual/household level (Beck and Heath 2013). One example of dietary modification is the simultaneous consumption of iron-rich foods with ascorbic acid (vitamin C) (Gibson 2014), which increases the amount of iron absorbed by the body. Decreasing the amount of coffee and tea consumed with meals containing iron-rich foods is another example of dietary modification, because coffee and tea inhibit iron absorption.

Other strategies to increase bioavailability include (1) using germinated cereal flours containing amylase to increase the energy and nutrient density of cereal-based porridges; and (2) using processes like germination, fermentation, and soaking to reduce the phytate content, which can interfere with iron and zinc absorption. These practices improve the intake and absorption of micronutrients, thus reducing anemia.

Measurement and data sources

Data on the commercial or individual/household-level dietary modification are not easily available. Currently, tools or indices to assess dietary modification practices are not developed. Still, the consumption of specific foods that enhance or inhibit the absorption of micronutrients can be measured. Population-based surveys that measure household, or individual-level food consumption, may list specific foods and processing practices that enhance or inhibit the absorption of micronutrients. National Micronutrient Surveys, the Optifood tool (FANTA 2016), and other population-based surveys with dietary intake modules, collect information about coffee and tea consumption, which can decrease iron absorption when consumed with meals containing iron-rich foods. Other dietary modification practices—using germinated cereal flours in cereal-based porridges or germination, fermentation, and soaking practices in cooking to reduce the phytate content—may be available from individual research studies (Hotz and Gibson 2001; Hotz, Gibson, and Temple 2001; Hotz and Gibson 2005). It’s important to note that these dietary modification practices may vary by geographic location within a country, or by cultural or ethnic groups.

Methodological issues

• Dietary modification practices, including processing and cooking methods, may vary significantly within a country. This makes findings difficult to generalize to national populations.