EAL

AWM: Eating Frequency and Patterns (2013)

Citation:

Holmback I, Ericson U, Gullberg B, Wirfalt E. A high eating frequency is associated with an overall healthy lifestyle in middle-aged men and women and reduced likelihood of general and central obesity in men. Br J Nutr. 2010; 104(7): 1,065-1,073.

PubMed ID: 20500929

Study Design:

Cross-Sectional Study

Class:

D - Click here for explanation of classification scheme.

Quality Rating:

POSITIVE: See Quality Criteria Checklist below.

Research Purpose:

To examine the associations between daily eating frequency (by examining the association between daily eating frequency and the intake of total energy, selected nutrients and food groups and lifestyle factors), BMI and waist circumference. Also to evaluate the potential confounding associated with possible reporting errors.

Inclusion Criteria:

Individuals that joined the MDC (Malmo Diet and Cancer Cohort) study from January 1993 until March 1994
Original population was defined as in 1991, all individuals living in the city of Malmo and born between 1926 and 1945
In May 1995, the cohort was extended to include all women born between 1923 and 1950 and all men born between 1923 and 1945.

Exclusion Criteria:

Inadequate Swedish language skills
Mental incapacity

Description of Study Protocol:

Recruitment

In the original population-based prospective study set, participants were invited by mail or advertisements in the local media and primary health-care centers. Participants visited the MDC screening center twice. During the first visit, participants were instructed on how to register meals in a menu book and how to fill out the questionnaires that were completed at home. Anthropometric measurements and blood collection were conducted. During the second visit (approximately 10 days later) the questionnaires were checked and a dietary interview was conducted by trained interviewers. This included 28,098 participants. To select this sub-sample cohort, only individuals that joined the MDC study from January 1993 until March 1994 were included (approximately 3,009 participants).

Design

Cross-sectional study.

Blinding Used

Cross-sectional studies are often hindered by the effects of misreporting by subjects as well as change in food habits over time. This study attempted to overcome these potential sources of bias by excluding both energy misreporters and subjects reporting to have changed their food habits substantially in the past.

Statistical Analysis

Analyzed men and women separately
Used the Chi-square test and ANOVA
The risk of overweight/obesity and central obesity associated with the daily eating frequency was estimated using logistic regression with six or more meals per day as the reference, while adjusting for age, education, socio-economic status, smoking, alcohol consumption, leisure-time physical activity and total energy intake
Other logistic regression models were in addition adjusted for nutrient and food group variables
OR and 95% CI were calculated
Significance level was set at P<0.05.

Data Collection Summary:

Timing of Measurements

Seven-day menu diary.

Dependent Variables

Eating frequency assessment: A questionnaire for assessing daily eating frequency that recorded the number and types of meals and snacks eaten during an ordinary day and how many times per week these meals or snacks usually were eaten. Self-reported information was checked by trained nutritionists during the diet history interview and eating frequencies were aggregated into:
- Three or fewer eating occasions per day
- Four to five eating occasions per day
- Six or more eating occasions per day
Dietary assessment: Used the interview-based modified diet history method of a seven-day menu book collecting descriptions of prepared meals, nutrient supplements and cold beverages (including alcoholic beverages) with a 168-item dietary questionnaire covering regularly eaten foods other than prepared meals during the previous year. Information provided was checked during a 45-minute interview and average energy and nutrition intakes were computed.
Dietary variables:
- Total energy intake (EI)
- Nutrient densities
- Intake of selected food groups
- Energy percentage (E%) from fat carbohydrates and protein (computed using non-alcohol energy and expressed as intake per MJ of non-alcohol energy)
- Alcohol was examined both as percentage of total energy and as alcohol habits
- Fiber (g per MJ)
- Fe (mg per MJ)
- Ca (mg per MJ)
- Mg (mg per MJ)
- B-carotene (mg per MJ)
- Ascorbic acid (mg per MJ)
- Folate (ug per MJ)
- Vitamin E (mg per MJ)
- Food groups
  - Fruits and vegetables
  - Meat, eggs and poultry
  - Low-fat meat
  - Fish and shellfish
  - Milk and dairy products
  - Low-fat dairy
  - Bread and cereals
  - High-fiber bread and cereals
  - Confectionery foods
  - Soft drinks
  - Cakes and pastries
Energy misreporting and past food habit change: Defined as having an energy intake (EI):basal metabolic rate (BMR) ratio outside the 95% CI limits of the calculated physical activity level; physical activity level information (hours and intensity of leisure-time physical activity, hours of household work and hours and intensity of occupational activities). Energy misreporting frequencies were aggregated into under-reporters of EI (EI:BMR below the lower 95% confidence limit); adequate-energy reporters (EI:BMR within the confidence limits); and over-reporters of EI (EI:BMR above the upper 95% confidence limit).
Anthropometric Variables:
- Weight
- Height
- Waist circumference
- BMI.

Independent Variables

Men and women.

Control Variables

All information regarding socio-economic and lifestyle variables was collected from a structured lifestyle questionnaire
Age
Education: Participants were divided into four categories to describe educational level (according to number of years of education completed)
Socio-economic status was classified according to the Swedish population census as blue-collar workers, white-collar workers and employers/self-employed
Smoking habits were defined as current smokers, former smokers or never-smokers
Alcohol habits were classified as zero (no/zero consumption), low (less than 15g per day for women and less than 20g per day for men), medium (15 to 30g per day for women and 20 to 40g per day for men), or high (more than 30g per day for women and more than 40g per day for men) consumption
Leisure-time physical activity was assessed by questions adapted from the Minnesota Leisure Time Physical Activity Questionnaire and categorized into quartiles based on the population distribution
Total energy intake.

Description of Actual Data Sample:

Initial N: 3,009 subjects (1,355 men and 1,654 women)
Attrition (final N): 3,009 subjects (1,355 men and 1,654 women)
Age: 47 to 68 years old
Location: Lund University in Malmo, Sweden.

Summary of Results:

Key Findings

Daily eating frequencies:
- On average, men reported a daily eating frequency of 4.8±1.2 with a range of one to 13 (median 4.7)
- On average, women reported a daily eating frequency of 5.0±1.1 with a range of one to nine (median 5.0)
- Majority of men and women reported eating between four to five meals per day; men were more likely than women to report three or fewer meals per day; women were more likely to to report an eating frequency of six or more meals per day
- Men and women with a low daily eating frequency (three or fewer) were more likely to be younger, current smokers, high alcohol consumers and less physically active compared with subjects reporting a high daily eating frequency (six or more); they were also more likely to under-report energy intake, but less likely to have changed their food habits substantially in the past compared with more frequent eaters
Mean relative energy and nutrient intakes across categories of daily eating frequency:
- Total energy intake, energy percentage from carbohydrates and relative fiber intake increased significantly with the daily eating frequency, while energy percentages from fat, protein and alcohol decreased
- Nutrient densities of ascorbic acid, folate and iron were highest for women reporting six or more meals per day
- In men, nutrient density of magnesium was higher for subjects with lower daily eating frequency (three or fewer and four to five meals per day)
- No significant differences in intakes of the various food groups apart from a higher intake of cake and pastries for women with a high eating frequency
Associations between daily eating frequency and the different overweight/obesity variables:
- Mean BMI and waist circumference among men and women across daily eating frequency did not differ significantly when adjusting for potential confounders, and excluding subjects who were classified as misreporters of energy intake and reported a change of food habits in the past year
- Men with a low daily eating frequency were more likely to be obese and have a large waist circumference compared with men with a high daily eating frequency (six or more)
- No significant statistical differences occurred in women
- The interaction between obesity, eating frequency and sex was non-significant
- Men with a low eating frequency still had an increased risk of general and central obesity.

Author Conclusion:

Results suggest that a high daily eating frequency is associated with an overall healthy lifestyle in both men and women
A high daily eating frequency was associated with higher leisure-time physical activity, non-smoking, lower alcohol consumption and lower energy percentage from fat and alcohol and higher energy percentage from carbohydrates and higher relative fiber intake
Men with a low eating frequency showed an increased risk of general and central obesity, which remained when adjusting for lifestyle and dietary factors
Results for women showed similar but non-significant tendencies
The daily eating frequency was linked to differences in dietary quality
There may be a favorable impact of increasing eating frequency in regards to preventing general and central obesity
The present study suggests that a high eating frequency in the context of an overall healthy lifestyle and a higher intake of low-fat and high-fiber foods may be inversely associated with the likelihood of general and central obesity in middle-aged men.

Funding Source:

University/Hospital:

Lund University and Region Skane

Not-for-profit

Ernhold Lundstrom Foundation

Other non-profit:

Reviewer 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)	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)	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?	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%.)	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?		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.)	Yes
	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?		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?	Yes
	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?	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?	Yes
	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