Measuring nutrition: Comparing different nutritional assessment tools and analyzing intra-household inequality in rural Kenya.

Good and improved nutrition is an essential driver of human development, a platform for progress in health and equality. But in spite of notable improvements in achieving global nutrition goals, the malnutrition and food security situation has worsened, especially in Sub-Saharan Africa. Underweight, micronutrient deficiencies and overweight/obesity are contributing factors to the multiple burdens of malnutrition globally. Worldwide, more than 800 million people remain undernourished and 2 billion people suffer from micronutrient deficiencies, caused by imbalanced diets. Stunted growth affects one out of four children, and 52 million children under the age of five are affected by acute malnutrition. At the same time, the global nutrition landscape recognizes a significant upward trend in the prevalence of overweight and obesity of adults, and children. Especially, low- and middle-income countries experience high rates of underweight, micronutrient deficiencies and overweight or obesity. Malnutrition affects one in three people directly and many even suffer from several deficiencies simultaneously. Kenya in particular, reports a substantial increase in overweight and obesity rates, while levels of undernutrition remain high. Moreover, intra-household inequality of malnutrition describes a situation where family members face different nutritional deficiencies within the same household. The identification of poor diets is especially important, as poor diets are one contributor to the global burden of malnutrition and an indicator of food insecurity. Therefore, it is important and necessary to keenly assess how nutrition is measured. Against this background, this dissertation presents two essays dealing with nutrition measurements. In the first essay, we investigate the association of results from different nutritional assessment tools for the same households and individuals. In the second essay, we identify different ways to define the double burden of malnutrition at household and individual level in rural Kenya. To measure nutrition, a wide set of assessment methods and indicators exist. Various tools measure and describe malnutrition and food insecurity, ranging from various food production and consumption based indicators up to anthropometric measurements and individual health outcomes. Each of the tools has a somewhat different focus and interpretation, but with the common aim to measure how well people are nourished. A positive correlation between the different indicators would be expected, but is that really true? Empirical evidence is limited, as many existing studies eventually rely on one approach, or a small set of indicators to display food and nutrition security and malnutrition. Therefore, relatively little is known about how closely results match when different assessment tools are used in the same context. The first essay of this dissertation directly addressed this question by comparing results from different assessment tools for the same households and individuals. The applied assessment tools build on seven-day food consumption and 24-hour dietary recalls at household and individual level. Individual height and weight measures were also taken. Different indicators of food access (energy consumption, household dietary diversity scores), dietary quality (individual dietary diversity scores, micronutrient intakes), and nutrition (anthropometric indicators) were calculated and correlated to evaluate their associations with data collected from 809 households and 1,556 individuals living in these households (female and male adults, and children aged 6-59 months). We found out that all measures of food access and dietary quality are positively correlated at individual level. Household level and individual level dietary indicators are also positively correlated. However, correlations between the dietary indicators and the anthropometric measures are very small and mostly statistically insignificant. We conclude that dietary indicators from seven-day food consumption recall at the household level can be used as proxies for individual dietary quality of children, male and female adults. The second essay deals with issues of nutritional inequality. Malnutrition is mostly assessed and calculated with anthropometric measurements. Through certain cut-off points and categorization schemes underweight, stunting, wasting, overweight and obesity are classified. Multiple forms of malnutrition coexist in various forms. The occurrence of undernutrition along with overweight in the same setting is often referred to as the double burden of malnutrition. Undernutrition, within the double burden of malnutrition definition, can be described as underweight, stunting, wasting or micronutrient deficiency. The phenomenon can occur at different levels; population level, household level and individual level. Coexistence of underweight, micronutrient deficiency along with overweight/obesity increases steadily in its prevalence, particularly in low- and middle-income countries. Indicators to define undernutrition within the double burden of malnutrition definition differ within articles, which make comparison difficult.   In the second essay, we analyze the double burden of malnutrition within households and individuals (male and female adults, and children <5 years) in rural Kenya. We identify and apply seven different double burden definitions to cross-sectional data. The first two double burden definitions show the coexistence of overweight/obesity and micronutrient deficiency of adults and children. Definitions three to seven are defined as an overweight/obese adult and an underweight, stunted, wasted or micronutrient deficient child. A total of 874 adults, 184 children, and 173 households were used in the calculations. We found out that micronutrient deficiency and overweight/obesity simultaneously occur in 19% of the adults and 10% of the children. Double burden at household level is also observed for all applied definitions. However, the magnitude of the double burden problem depends much on the particular definition used, so comparisons across different surveys and definitions have to be done with caution.