EAL

HD: Food Security (2011)

Citation:

Study Design:

Class:

- Click here for explanation of classification scheme.

Quality Rating:

Research Purpose:

To further the understanding of the dietary behaviors of food-insecure individuals
To examine the association between food insecurity and total daily energy and macronutrient intakes in American men and women.

Inclusion Criteria:

National Center of Health Statistics' (NCHS) National Health and Nutrition Examination Survey (NHANES) for 1999-2002 data were used with the following inclusion criteria:

Adults (at least 18 years old, less than 60 years old)
Completed adult-level Food Security Survey Module (FSSM).

Exclusion Criteria:

National Center of Health Statistics' (NCHS) National Health and Nutrition Examination Survey (NHANES) for 1999-2002 data were used with the following exclusion criteria:

Less than 18 years of age
60 years of age or older
Women who were pregnant
Women who were breastfeeding
Adults who did not complete the FSSM.

Description of Study Protocol:

Recruitment

NCHS NHANES for 1999-2002 sample was utilized.

Design

10-item adult FSSM data were used

Individual dietary intakes were collected through an interviewer-administered 24-hour recall method
Snack and meal occasions were specified
Nutrient intakes
- Included nutrients from foods and beverages other than drinking water
- Did not include nutrients from dietary supplements, medications or plain drinking water.
Energy contributions per snack, per meal and total energy contributions of snacks and meals were calculated
Relative caloric contribution of food groups defined by US Department of Agriculture Food and Nutrient Database for Dietary Studies, 1.0 (2004, Beltsville, MD: Agriculture Research Service, Food Surveys Research Group) were calculated
Energy density values (kcal per gram) were calculated for food items only.

Blinding Used

Not applicable.

Intervention

Not applicable.

Statistical Analysis

Multivariate linear regression was used to examine relationship between food security status and dietary outcomes
- Cofounders included
  - Age
    - 18 to up to 30 years old
    - Over 30 to under 60 years old.
  - Race-ethnicity
    - Non-Hispanic white
    - Non-Hispanic black
    - Hispanic.
  - Education
    - No high school degree
    - High school graduate.
  - Income: Defined as ratio with each household's income, compared with appropriate poverty threshold.
- Food-secure individuals were used as a referent group in all models.
STATA (Version 8.0; STATA, College Station, TX) used to estimate all descriptive and inferential statistics. Used to account for mobile examination center sample design and sampling weights.
Chi-squared tests of independence were used to determine whether cofounders were differentially distributed among levels of food security
P≤0.05 was considered statistically significant.

Data Collection Summary:

Timing of Measurements

NHANES data collected from 1999 to 2002
FSSM data covers 12 months prior to completion of the survey
Interviewer-administered 24-hour recall covers 24 hours prior to recall collection.

Dependent Variables

Food security measure: 10-item adult FSSM with categories

Food-secure (FS)
Marginally FS (MFS)
Food-insecure (FI) without hunger (FIWOH)
FI with hunger (FIWH).

Independent Variables

Diet assessment measure: Interviewer-administered 24-hour recall used to calculate
- Nutrient intake
- Meal occasions
- Snacking occasions
- Energy per snack
- Energy per meal
- Energy density
  - Total
  - Per meal
  - Per snack.
Gender.

Control Variables

Age
Ethnicity
Education
Income.

Description of Actual Data Sample:

Initial N

5,640 adults

2,707 women
2,933 men.

Attrition (Final N)

5,640 adults

2,707 women
2,933 men.

Age

19 to up to 30 years old: 1,579 men and women
Over 30 to less than 60 years old: 4,061 men and women.

Ethnicity

Hispanic: 846 men and women
Non-Hispanic white: 4,174 men and women
Non-Hispanic black: 620 men and women.

Other Relevant Demographics

Education
- Less than high school education: 1,072 men and women
- High school education or more: 4,568 men and women
Income
- Overall Poverty Income ratio: 3.00±0.07 (mean± SEM)
- Poverty Income ratio, food-secure
  - Women: 3.24±0.08
  - Men: 3.39±0.07.
- Poverty Income ratio, marginally food-secure
  - Women: 1.45±0.10
  - Men: 1.71±0.12.
- Poverty Income ratio, food-insecure without hunger
  - Women: 1.39±0.14
  - Men: 1.39±0.09.
- Poverty Income ratio, food-insecure with hunger
  - Women: 1.11±0.08
  - Men: 1.18±0.10.
Food security
- Food-secure
  - 2,092 women
  - 2,233 men.
- Marginally food-secure
  - 244 women
  - 239 men.
- Food-insecure without hunger
  - 226 women
  - 293 men.
- Food-insecure with hunger
  - 145 women
  - 168 men.

Anthropometrics

None provided.

Location

United States.

Summary of Results:

Key Findings

Differences across levels of food security for men and women were found for every characteristic (age, race-ethnicity, education, income)
Energy and macronutrient intake: Differences in energy intake were not observed among men or women
Meal occasions
- FIWOH and FIWH women had significantly fewer meals than FS women
- FIWOH men had significantly fewer meals than FS men.
Snack occasions: FIWOH men had a significantly higher daily number of snacks than FS men
Energy contributions of meals: FIWOH women had a significantly greater mean energy contribution from each meal than FS women
Energy contributions of snacks
- FIWOH women had a significantly greater total energy contributed from snacking than FS women
- FIWOH men had significantly more total energy contributed from snacking than FS men
- FIWOH men consumed snack foods that had a significantly lower energy density than FS men.
Food group contributions to meal energy intake: Major sources of energy were similar for all levels of food security for both women and men
- Grain group was major source of energy
- Meat, poultry, fish, egg and mixtures group was second largest energy source
- Sugars, sweets and beverages group was third largest energy source.

Other Findings

Energy and macronutrient intake
- MFS women had significantly higher intakes of protein than FS women
- FIWH women had significantly higher intakes of total fat than FS women
- FIWH women had significantly higher intakes of saturated fat than FS women.
Food group contributions to snack energy intake
- Major source of energy for men and women was sugar, sweets and beverages group
  - 35% of energy among FS women
  - 39% of energy among MFS women
  - 41% of energy among FS men
  - 45% of energy among MFS men
  - 42% of energy among FIWOH men
  - 53% of energy among FIWH men.
- Grain group was the second largest source of energy for women
- Dairy group was the third largest source of energy for women.

Author Conclusion:

FI and FS daily energy intakes did not differ
An increase in meal size and the energy obtained by snacking appears to compensate for a reduced meal frequency among FI individuals: Increase in snacking energy may be attributed to an increase in snacking frequency among FIWOH men
Skipping meals can be associated with diets that are adequate and possibly more than adequate in energy
Focusing solely on total energy intake is likely to miss important consequences of food insecurity
Nutrition interventions aimed at FI audiences should also target meal and snack behaviors.

Funding Source:

Government:

US Department of Agriculture, Economic Research Service, Research, Innovation, and Development Grants in Economics (RIDGE) Grants and the Alabama Agricultural Experiment Station (ALA013-020)

Reviewer Comments:

No comments.

Quality Criteria Checklist: Primary Research
Relevance Questions
	1.	Would implementing the studied intervention or procedure (if found successful) result in improved outcomes for the patients/clients/population group? (Not Applicable for some epidemiological studies)	Yes
	2.	Did the authors study an outcome (dependent variable) or topic that the patients/clients/population group would care about?	Yes
	3.	Is the focus of the intervention or procedure (independent variable) or topic of study a common issue of concern to dieteticspractice?	Yes
	4.	Is the intervention or procedure feasible? (NA for some epidemiological studies)	N/A

Validity Questions
1.	Was the research question clearly stated?		Yes
	1.1.	Was (were) the specific intervention(s) or procedure(s) [independent variable(s)] identified?	Yes
	1.2.	Was (were) the outcome(s) [dependent variable(s)] clearly indicated?	Yes
	1.3.	Were the target population and setting specified?	Yes
2.	Was the selection of study subjects/patients free from bias?		Yes
	2.1.	Were inclusion/exclusion criteria specified (e.g., risk, point in disease progression, diagnostic or prognosis criteria), and with sufficient detail and without omitting criteria critical to the study?	Yes
	2.2.	Were criteria applied equally to all study groups?	Yes
	2.3.	Were health, demographics, and other characteristics of subjects described?	Yes
	2.4.	Were the subjects/patients a representative sample of the relevant population?	Yes
3.	Were study groups comparable?		Yes
	3.1.	Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT)	Yes
	3.2.	Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline?	Yes
	3.3.	Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.)	Yes
	3.4.	If cohort study or cross-sectional study, were groups comparable on important confounding factors and/or were preexisting differences accounted for by using appropriate adjustments in statistical analysis?	Yes
	3.5.	If case control study, were potential confounding factors comparable for cases and controls? (If case series or trial with subjects serving as own control, this criterion is not applicable.)	Yes
	3.6.	If diagnostic test, was there an independent blind comparison with an appropriate reference standard (e.g., "gold standard")?	N/A
4.	Was method of handling withdrawals described?		Yes
	4.1.	Were follow-up methods described and the same for all groups?	N/A
	4.2.	Was the number, characteristics of withdrawals (i.e., dropouts, lost to follow up, attrition rate) and/or response rate (cross-sectional studies) described for each group? (Follow up goal for a strong study is 80%.)	N/A
	4.3.	Were all enrolled subjects/patients (in the original sample) accounted for?	Yes
	4.4.	Were reasons for withdrawals similar across groups?	N/A
	4.5.	If diagnostic test, was decision to perform reference test not dependent on results of test under study?	N/A
5.	Was blinding used to prevent introduction of bias?		N/A
	5.1.	In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate?	N/A
	5.2.	Were data collectors blinded for outcomes assessment? (If outcome is measured using an objective test, such as a lab value, this criterion is assumed to be met.)	N/A
	5.3.	In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded?	N/A
	5.4.	In case control study, was case definition explicit and case ascertainment not influenced by exposure status?	N/A
	5.5.	In diagnostic study, were test results blinded to patient history and other test results?	N/A
6.	Were intervention/therapeutic regimens/exposure factor or procedure and any comparison(s) described in detail? Were interveningfactors described?		Yes
	6.1.	In RCT or other intervention trial, were protocols described for all regimens studied?	N/A
	6.2.	In observational study, were interventions, study settings, and clinicians/provider described?	N/A
	6.3.	Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect?	Yes
	6.4.	Was the amount of exposure and, if relevant, subject/patient compliance measured?	N/A
	6.5.	Were co-interventions (e.g., ancillary treatments, other therapies) described?	N/A
	6.6.	Were extra or unplanned treatments described?	N/A
	6.7.	Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups?	Yes
	6.8.	In diagnostic study, were details of test administration and replication sufficient?	N/A
7.	Were outcomes clearly defined and the measurements valid and reliable?		Yes
	7.1.	Were primary and secondary endpoints described and relevant to the question?	Yes
	7.2.	Were nutrition measures appropriate to question and outcomes of concern?	Yes
	7.3.	Was the period of follow-up long enough for important outcome(s) to occur?	Yes
	7.4.	Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures?	Yes
	7.5.	Was the measurement of effect at an appropriate level of precision?	Yes
	7.6.	Were other factors accounted for (measured) that could affect outcomes?	Yes
	7.7.	Were the measurements conducted consistently across groups?	Yes
8.	Was the statistical analysis appropriate for the study design and type of outcome indicators?		Yes
	8.1.	Were statistical analyses adequately described and the results reported appropriately?	Yes
	8.2.	Were correct statistical tests used and assumptions of test not violated?	Yes
	8.3.	Were statistics reported with levels of significance and/or confidence intervals?	Yes
	8.4.	Was "intent to treat" analysis of outcomes done (and as appropriate, was there an analysis of outcomes for those maximally exposed or a dose-response analysis)?	N/A
	8.5.	Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)?	Yes
	8.6.	Was clinical significance as well as statistical significance reported?	N/A
	8.7.	If negative findings, was a power calculation reported to address type 2 error?	N/A
9.	Are conclusions supported by results with biases and limitations taken into consideration?		Yes
	9.1.	Is there a discussion of findings?	Yes
	9.2.	Are biases and study limitations identified and discussed?	Yes
10.	Is bias due to study's funding or sponsorship unlikely?		Yes
	10.1.	Were sources of funding and investigators' affiliations described?	Yes
	10.2.	Was the study free from apparent conflict of interest?	Yes