Food in the home and obesity

The validation of a home food inventory
Original source: International Journal of Behavioral Nutrition and Physical Activity 2008, 5:55
Authors: Jayne A Fulkerson (corresponding author), Melissa C Nelson, Leslie Lytle, Stacey Moe, Carrie Heitzler, and Keryn E Pasch
Publication date: 4 November 2008
DOI (digital document ID): 10.1186/1479-5868-5-55
Requires subscription? No
Publicly-available abstract: Yes

Synopsis:
A validated home food inventory can be a useful tool to assess what foods are readily available to a person or family, and by consequence, what foods are frequently eaten. This differs from a self-reported food inventory, as it allows a trained professional to independently inventory both the items in general and their relative quantities, and for the results to be compared with the self-reported inventory. The authors of this study are looking to see if there is a relationship between the types of food available in the home and the likelihood that members of that household are obese.

The authors find that in many previous studies on home food inventories, the list of foods leaves out a lot of categories and specific foods, and there have been few attempts to see if the person doing the reporting is accurately including all the food and food types in the household. They note four previous studies that have had validation, each of which has focused only on a small group of food items, with a particular health goal in mind.

Their goal is to create a comprehensive food inventory, which can be completed by an average adult, and which takes into account both healthy and unhealthy foods, as well as "reduced fat" versions of foods often associated with obesity.

Using both trained volunteers and volunteers from the community, they developed a home food inventory form. They validated the inventories for 51 families and analyzed the results for accuracy of self-reporting. They then distributed the inventory survey to 349 families with adolescent children, measured the adults and the children and recorded their demographic characteristics, and then asked them what foods they ate over the previous 24 hours. They were given information on how to estimate portion sizes, and told to expect three phone calls over the next month asking them to recall their food intake for the past 24 hours. In addition, dietary health questionnaires were distributed; these are shown to be relatively accurate in assessing the usual food and nutrients that the participant consumes.

The final home food inventory included 190 items which were community-specific. Participants were instructed on key package words that might indicate a reduced-fat version of a dessert or snack food, since these were categorized separately from the original (full-fat/full-sugar) versions.

Foods were ranked according to their association with obesity, or the likelihood that eating a lot of those foods would cause a person to become obese over time.

The home food inventories filled out by the initial 51 families in the pilot project were compared with the identical inventory filled out by the trained volunteers to determine whether or not the consumers understood brands as being part of larger categories, and how well they understood the questionnaire overall. The results showed a high degree of correlation, which the researchers take to mean that an unvalidated inventory should be reasonably accurate.

The researchers note several limitations of the study, including some issues with correctly categorizing a number of prepared foods and frozen desserts, the limitation of specific food items and types, and the limitation of food items and categories to "yes-no" answers rather than measuring quantity and variety. The initial set of families had a greater number of educated Caucasian adults than was representative of the community at large, and may not accurately represent the responses of less-educated and/or non-white populations.

Reliability:
The authors are affiliated with the University of Minnesota, in the professional realms of nursing and community health. The study was published in a peer-reviewed journal.
The researchers note that there are several food categories that were not as well-correlated as others -- primarily, prepared and frozen desserts, and breads. Some of this is due to the large variety of products available in these categories.
There is some limitation in correlating food inventories with dietary intake, as about half of the the foods listed in the 24-hour recalls were not on the home food inventories. (This would suggest a fair amount of eating outside the home.)

Practical Applications:
A useful, friendly home food inventory is a basic tool that anybody can use in menu planning, grocery shopping, and disaster planning. It is also a tool that can provide your nutritionist, social worker, or Certified Diabetes Educator a better idea of what foods you have, and what you regularly eat. This information is helpful in showing you ways to improve your diet to lose weight, maintain healthy blood glucose levels, and reduce your risks of cardiovascular disease.

A validated home food inventory is also a useful basis from which to gather information for community health and public health studies regarding nutrition and health.

This synopsis was based on the entire article.