EAL

AWM: Eating Frequency and Patterns (2013)

Citation:

Study Design:

Class:

- Click here for explanation of classification scheme.

Quality Rating:

Research Purpose:

To examine the association between several eating behaviours and obesity in a representative sample of the adult population of Spain
To analyze the influence of socio-demographic and lifestyle factors on such association.

Inclusion Criteria:

Representative sample of the non-institutionalized Spanish population aged 25 to 64 years.

Exclusion Criteria:

None specified.

Description of Study Protocol:

Recruitment

Data were drawn from the 1999 Survey on Disabilities, Impairments and Health Status, which covered a representative sample of the non-institutionalized Spanish population. Study participants were selected through two-stage stratified sampling. First, census sections were randomly selected, stratified by town size and socio-economic level of the household. Second, random-start systematic sampling was use to select family dwellings, where one person was chosen at random to answer the questionnaire.

Design

Cross-sectional study.

Statistical Analysis

The association between the principal independent variables and obesity was summarized with OR and their 95% CI obtained from logistic regression
Four types of models were built:
- A crude model
- An age-adjusted model
- A model adjusted for age, health status and lifestyle variables
- A saturated model, which, in addition to the above variables, also adjusted for socio-demographic factors
Separate analyses were conducted for men and women
Statistical significance was set at two-tailed P<0.05. Analyses were performed with the SPSS version 12.0 software.

Data Collection Summary:

Timing of Measurements

Single interview with subject.

Dependent Variables

Obesity: Estimated from the BMI, calculated as weight in kilograms divided by the square of the height in meters (kg/m²). Height and weight were self-reported.

Independent Variables

Eating habits in the six months preceding the interview were assessed using an interview about whether each meal was eaten regularly and where it was eaten (at home or away) and eating frequency.

Control Variables

Socio-demographic variables:
- Sex
- Age
- Size of town of usual residence
- Education
Lifestyle variables
- Smoking
- Alcohol consumption
- Leisure-time physical activity
- Self-perceived health.

Description of Actual Data Sample:

Initial N: 69,555 interviews were conducted
Attrition (final N): Analyses was restricted to the 35,190 individuals aged 25 to 64 years; 216 were excluded with missing data on some variable of interest. Final N=34,974.
Age: 25 to 64 years.

Demographic and Lifestyle Characteristics of Spanish Men and Women Aged 25 to 64 Years

	Men N	Men Number Obese	Men Prevalence(Percent)	Women N	Women Number Obese	Women Prevalence (Percent)
Age (year)
25 to 34	4,792	368	7.7	4,762	189	4.0
35 to 44	4,389	470	10.7	4,403	339	7.7
45 to 54	3,874	546	14.1	4,206	624	14.8
55 to 64	3,874	661	17.1	4,674	967	20.7
Trend P-value			P<0.001			P<0.001
Physical activity
Sedentary	7,435	1107	14.9	8,215	1169	14.2
Active	9,494	938	9.9	9,830	950	9.7
Smoking
Non-smoker	5,606	620	11.1	11,030	1641	14.9
Smoker	7,735	833	10.8	5,207	303	5.8
Ex-smoker	3,588	592	16.5	1,808	175	9.7
Alcohol consumption
Abstainer	5,513	684	12.4	11,631	1622	13.9
Occasional	3,279	374	11.4	3,383	254	7.5
Frequent	2,851	328	11.5	1,403	90	6.4
Daily	5,286	659	12.5	1,628	153	9.4
Health status
Good	13,421	1417	10.6	12,904	1021	7.9
Poor	3,508	628	17.9	5,141	1098	21.4
Educational level
High	9,275	842	9.1	9,095	464	5.1
Low	7,654	1203	15.7	8,950	1655	18.5
Town size (inhabitants)
Less than 10,000	3,926	551	14.0	3,825	559	14.6
10,001 to 50,000	4,045	504	12.5	4,178	519	12.4
50,001 to 500,000	6,947	772	11.1	7,746	817	10.5
More than 500,000	2,011	218	10.8	2,296	224	9.8
Trend P value			P<0.001			P<0.001
Marital status
Single	5,847	567	9.7	5,938	540	9.1
Married	11,082	1478	13.3	12,107	1579	13.0

Location: Spain.

Summary of Results:

Key Findings

Those skipping breakfast were more likely to be obese, both in men (OR=1.58; 95% CI: 1.29, 1.93) and women (OR, 1.53; 95% CI: 1.15, 2.03)
Women who had no dinner showed a higher prevalence of obesity than those who had dinner at home (OR=1.76; 95% CI: 1.29, 2.41), which remained significant in the saturated model (OR= 1.66; 95% CI: 1.20, 2.29)
Obesity was more prevalent in those having only two meals per day than in those having three or four meals in men (OR=1.63; 95% CI: 1.37, 1.95) and women (OR=1.30; 95% CI: 1.05, 1.62), after adjustment for socio-economic and demographic variables
Eating several smaller-sized meals per day was associated with obesity in women (OR=1.51; 95% CI: 1.17, 1.95)
No association was observed between obesity and having one or more of the main meals away from home in either sex.

OR and 95% CI of Obesity According to Eating Habits in Spanish men Aged 25 to 64 Years

	Crude OR	Crude 95% CI	Adjusted for Age OR	Adjusted for Age 95% CI	Adjusted for Age and Lifestyle OR	Adjusted for Age and Lifestyle 95% CI	Adjusted for Age, Lifestyle, and Socio-demographic Factors OR	Adjusted for Age, Lifestyle, and Socio-demographic Factors 95%CI
Breakfast
At home	1.00		1.00		1.00		1.00
Away from home	1.04	0.92, 1.18	1.13	0.99, 1.28	1.12	0.98, 1.27	1.12	0.00, 1.28
No breakfast	1.54	1.26, 1.87	1.61	1.32, 1.97	1.55	1.30, 1.89	1.58	1.29, 1.93
Luncheon
At home	1.00		1.00		1.00		1.00
Away from home	0.91	0.81, 1.01	1.00	0.89, 1.12	1.01	0.90, 1.13	1.03	0.92, 1.15
No lunch	0.16	0.02, 1.10	0.19	0.03, 1.29	0.18	0.03, 1.27	0.19	0.01, 1.31
Dinner
At home	1.00		1.00		1.00		1.00
Away from home	0.98	0.82, 1.17	1.11	0.93, 1.33	1.11	0.93, 1.33	1.14	0.95, 1.37
No dinner	1.33	0.87, 2.20	1.35	0.88, 2.06	1.25	0.81, 1.91	1.29	0.84, 1.98
Daily eating frequency
Three or four times	1.00		1.00		1.00		1.00
Twice	1.61	1.36, 1.91	1.67	1.41, 1.99	1.62	1.36, 1.93	1.63	1.37, 1.95
Once	1.31	0.88, 1.97	1.38	0.92, 2.10	1.34	0.89, 2.02	1.42	0.99, 2.01
Several times (small amounts)	1.50	1.07, 2.11	1.50	.06, 2.12	1.43	1.01, 2.03	1.42	0.99, 2.01

OR and 95% CI of Obesity According to Eating Habits in Spanish Women Aged 25 to 64 Years

	Crude OR	Crude 95% CI	Adjusted for Age OR	Adjusted for Age 95% CI	Adjusted for Age and Lifestyle OR	Adjusted for Age and Lifestyle 95% CI	Adjusted for Age, Lifestyle and Socio-demographic Factors OR	Adjusted for Age, Lifestyle and Socio-demographic Factors 95% CI
Breakfast
At home	1.00		1.00		1.00		1.00
Away from home	0.64	0.51, 0.79	0.85	0.68, 1.06	0.95	0.75, 1.19	1.07	0.86, 1.36
No breakfast	1.43	1.09, 1.86	1.65	1.26, 2.17	1.56	1.18, 2.06	1.53	1.15, 2.03
Luncheon
At home	1.00		1.00		1.00		1.00
Away from home	0.52	0.43, 0.73	0.78	0.64, 0.95	0.88	0.72, 1.07	1.03	0.84, 1.26
No lunch	0.67	0.29, 1.54	0.88	0.38, 2.08	1.03	0.44, 2.42	1.15	0.48, 2.72
Dinner
At home	1.00		1.00		1.00		1.00
Away from home	0.52	0.37, 0.73	0.77	0.55, 1.08	0.91	0.64, 1.28	1.03	0.84, 1.26
No dinner	1.65	1.21, 2.23	1.76	1.29, 2.41	1.60	1.16, 2.21	1.66	1.20, 2.29
Daily eating frequency
Three or four times	1.00		1.00		1.00		1.00
Twice	1.20	0.98, 1.48	1.35	1.09, 1.67	1.30	1.05, 1.62	1.30	1.05, 1.62
Once	1.28	0.84, 1.97	1.28	0.83, 1.99	1.11	0.71, 1.74	1.11	0.71, 1.79
Several times (small amounts)	1.65	1.30, 2.10	1.63	1.28, 2.09	1.53	1.19, 1.97	1.51	1.17, 1.95

Author Conclusion:

Skipping breakfast and eating frequency were associated with obesity
The lack of association between eating away from home and obesity is in contrast to most previous research conducted in Anglo-Saxon countries.

Funding Source:

Government:

FIS grant 06/0366

Reviewer Comments:

The dependent variable, obesity, was calculated from self-reported weight and height.

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)	N/A
	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)	N/A
	3.2.	Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline?	N/A
	3.3.	Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.)	N/A
	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?	Yes
	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%.)	Yes
	4.3.	Were all enrolled subjects/patients (in the original sample) accounted for?	Yes
	4.4.	Were reasons for withdrawals similar across groups?	Yes
	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?		Yes
	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?	Yes
	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?		N/A
	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?	N/A
	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?	N/A
	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?	N/A
	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?	Yes
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