Validation of measures of food insecurity and hunger.
The most recent survey effort to determine the extent of food insecurity and hunger in the United States, the Food Security Supplement, included a series of questions to assess this complex phenomenon. The primary measure developed from this Food Security Supplement was based on measurement concepts, methods and items from two previously developed measures. This paper presents the evidence available that questionnaire-based measures, in particular the national food security measure, provide valid measurement of food insecurity and hunger for population and individual uses. The paper discusses basic ideas about measurement and criteria for establishing validity of measures and then uses these criteria to structure an examination of the research results available to establish the validity of food security measures. The results show that the construction of the national food security measure is well grounded in our understanding of food insecurity and hunger, its performance is consistent with that understanding, it is precise within usual performance standards, dependable, accurate at both group and individual levels within reasonable performance standards, and its accuracy is attributable to the well-grounded understanding. These results provide strong evidence that the Food Security Supplement provides valid measurement of food insecurity and hunger for population and individual uses. Further validation research is required for subgroups of the population, not yet studied for validation purposes, to establish validity for monitoring population changes in prevalence and to develop and validate robust and contextually sensitive measures in a variety of countries that reflect how people experience and think about food insecurity and hunger. (+info)
Measuring food insecurity and hunger in the United States: development of a national benchmark measure and prevalence estimates.
Since 1992, the U.S. Department of Agriculture Food and Nutrition Service (FNS) has led a collaborative effort to develop a comprehensive benchmark measure of the severity and prevalence of food insecurity and hunger in the United States. Based on prior research and wide consultation, a survey instrument specifically relevant to U.S. conditions was designed and tested. Through its Current Population Survey (CPS), the U.S. Bureau of the Census has fielded this instrument each year since 1995. A measurement scale was derived from the data through fitting, testing and validating a Rasch scale. The unidimensional Rasch model corresponds to the form of the phenomenon being measured, i.e., the severity of food insufficiency due to inadequate resources as directly experienced and reported in U.S. households. A categorical measure reflecting designated ranges of severity on the scale was constructed for consistent comparison of prevalence estimates over time and across population groups. The technical basis and initial results of the new measure were reported in September 1997. For the 12 months ending April 1995, an estimated 11.9% of U.S. households (35 million persons) were food insecure. Among these, 4.1% of households (with 6.9 million adults and 4.3 million children) showed a recurring pattern of hunger due to inadequate resources for one or more of their adult and/or child members sometime during the period. The new measure has been incorporated into other federal surveys and is being used by researchers throughout the U.S. and Canada. (+info)
Economic determinants and dietary consequences of food insecurity in the United States.
This paper reviews recent research on the economic determinants and dietary consequences of food insecurity and hunger in the United States. The new Current Population Study (CPS) food insecurity and hunger measure shows that hunger rates decline sharply with rising incomes. Despite this strong relationship, confirmed in other national datasets, a one-to-one correspondence between poverty-level incomes and hunger does not exist. In 1995, 13.1% of those in poverty experienced hunger and half of those experiencing hunger had incomes above the poverty level. Panel data indicate that those who are often food insufficient are much more likely than food-sufficient households to have experienced recent events that stress household budgets, such as losing a job, gaining a household member or losing food stamps. Cross-sectional work also demonstrates the importance of food stamps because benefit levels are inversely related to food insufficiency. Concern for the dietary consequences of domestic food insufficiency is well placed; recent research shows that the odds of consuming intakes <50% of the recommended dietary allowance (RDA) are higher for adult women and elderly individuals from food-insufficient households. Preschoolers from food-insufficient households do not consume significantly lower amounts than those from food-sufficient households, but mean intakes for the rest of members in those very same households are significantly lower for the food insufficient. This research highlights the importance of food insecurity and hunger indicators, further validates the use of self-reported measures and points to areas of need for future research and interventions. (+info)
Nutrition and health outcomes associated with food insecurity and hunger.
This paper explores how food insecurity and hunger relate to health and nutrition outcomes in food-rich countries such as the United States. It focuses on two subgroups of the population for whom data are available: women of childbearing age and school-age children. Special consideration is given to examining how food insecurity relates to these outcomes independently of socioeconomic status and poverty. In a population-based sample of women of childbearing age, the least severe level of food insecurity (household food insecurity) was correlated with higher body mass index (BMI), controlling for other available and known influences on obesity including income level. In low income school-age children from two large urban areas of the U.S., risk of hunger and hunger were associated with compromised psychosocial functioning, controlling for maternal education and estimated household income. The nutrition and health consequences of food insecurity comprise a potentially rich area for future, socially relevant research in the field of nutritional sciences. (+info)
Food insecurity: consequences for the household and broader social implications.
A conceptual framework showing the household and social implications of food insecurity was elicited from a qualitative and quantitative study of 98 households from a heterogeneous low income population of Quebec city and rural surroundings; the study was designed to increase understanding of the experience of food insecurity in order to contribute to its prevention. According to the respondents' description, the experience of food insecurity is characterized by two categories of manifestations, i.e., the core characteristics of the phenomenon and a related set of actions and reactions by the household. This second category of manifestations is considered here as a first level of consequences of food insecurity. These consequences at the household level often interact with the larger environment to which the household belongs. On a chronic basis, the resulting interactions have certain implications that are tentatively labeled "social implications" in this paper. Their examination suggests that important aspects of human development depend on food security. It also raises questions concerning the nature of socially acceptable practices of food acquisition and food management, and how such acceptability can be assessed. Guidelines to that effect are proposed. Findings underline the relevance and urgency of working toward the realization of the right to food. (+info)
Women's dietary intakes in the context of household food insecurity.
A study of food insecurity and nutritional adequacy was conducted with a sample of 153 women in families receiving emergency food assistance in Toronto, Canada. Contemporaneous data on dietary intake and household food security over the past 30 d were available for 145 of the women. Analyses of these data revealed that women who reported hunger in their households during the past 30 d also reported systematically lower intakes of energy and a number of nutrients. The effect of household-level hunger on intake persisted even when other economic, socio-cultural, and behavioral influences on reported dietary intake were considered. Estimated prevalences of inadequacy in excess of 15% were noted for Vitamin A, folate, iron, and magnesium in this sample, suggesting that the low levels of intake associated with severe household food insecurity are in a range that could put women at risk of nutrient deficiencies. (+info)
Abbreviated measures of food sufficiency validly estimate the food security level of poor households: measuring household food security.
This study was designed to develop an abbreviated method that captures both the qualitative and quantitative dimensions of household food security (HFS). Women in poor and very poor households (n = 238) in a peri-urban barrio in Caracas, Venezuela, provided data on food availability and their perception of food resource constraints and hunger experiences within the home. Socioeconomic data and food-related behavior that may predict HFS levels were gathered. On average, the top 12 food contributors of energy provided 81% and predicted more than 90% of the variation in households' total energy availability using stepwise regression analysis. On the other hand, a 4-point 12-item scale was shown to have face, content and construct validity with reiterative testing, factor analysis and a Chronbach's alpha coefficient of 0.92. Assessing predictors of energy availability together with a self-perceived HFS scale may provide a valid and reliable method for identifying and monitoring food security levels among poor urban households. (+info)
Neuroanatomical correlates of hunger and satiation in humans using positron emission tomography.
The central role of the hypothalamus in the origination and/or processing of feeding-related stimuli may be modulated by the activity of other functional areas of the brain including the insular cortex (involved in enteroceptive monitoring) and the prefrontal cortex (involved in the inhibition of inappropriate response tendencies). Regional cerebral blood flow (rCBF), a marker of neuronal activity, was measured in 11 healthy, normal-weight men by using positron emission tomography in a state of hunger (after 36-h fast) and a state of satiation (after a liquid meal). Hunger was associated with significantly increased rCBF in the vicinity of the hypothalamus and insular cortex and in additional paralimbic and limbic areas (orbitofrontal cortex, anterior cingulate cortex, and parahippocampal and hippocampal formation), thalamus, caudate, precuneus, putamen, and cerebellum. Satiation was associated with increased rCBF in the vicinity of the ventromedial prefrontal cortex, dorsolateral prefrontal cortex, and inferior parietal lobule. Changes in plasma insulin concentrations in response to the meal were negatively correlated with changes in rCBF in the insular and orbitofrontal cortex. Changes in plasma free fatty acid concentrations in response to the meal were negatively correlated with changes in rCBF in the anterior cingulate and positively correlated with changes in rCBF in the dorsolateral prefrontal cortex. In conclusion, these findings raise the possibility that several regions of the brain participate in the regulation of hunger and satiation and that insulin and free fatty acids may be metabolic modulators of postprandial brain neuronal events. Although exploratory, the present study provides a foundation for investigating the human brain regions and cognitive operations that respond to nutritional stimuli. (+info)