AWM: Eating Frequency and Patterns (2013)
Kant AF, Schatzkin A, Graubard BI, Ballard-Barbash R. Frequency of eating occasions and weight change in the NHANES I Epidemiologic Follow-up Study. Intl J Obes. 1995;19:468-74.
Recruitment Previously reported
Design Data was used form the NHANES I (1971-75) and NHANES I Epidemiologic Follow-up Study (1982-84) (NHEFS).
Blinding used (if applicable) NA
Intervention (if applicable) NA
Statistical Analysis regression analyses
Timing of Measurements 2 times, in 1971-75 and 1982-84
- weight change
- frequency of eating occasion (entered as a continuous and categorical variable)- frequency of eating occasions was estimated by summing the energy yielding consumption reported at one time using a single 24-hour recall at Time 1. Occasions when non-caloric intake was reported was not counted. At follow-up respondents were asked one question each regarding the number of meals and number of snacks consumed daily and weight was measured.
- education (<12, 12, >12 years)
- smoking status (never, former, current)
- baseline BMI
- length of follow-up
- energy intake - 1 24-hour recall
- alcohol (0, <9.35 g, > 9.35 g)
- special diet status (yes or no)
- self-reported physical activity at baseline and follow-up (a lot, moderate, and little)
- presence of physician confirmed morbidty (0=no, 1=1 positive response, 2=2 positive responsed, and 3 >3 positive responses)
Initial N:For NHANES I: 14,407, for NHEFS 10,424
Attrition (final N): 7141 (large numbers were excluded for missing or unreliable data). Resulting n is 68% of eligible cohort of 10,424. 2580 men, 4567 women
Age: men=44.5 years, women = 45.9 years
Ethnicity: not reported
Other relevant demographics: Not reported for entire sample. Although 68% of the original smple was used for analysis, this sub-sample was similar to the original cohort in terms of age, eating frequency, baseline BMI, and energy intake.
Anthropometrics not reported for entire sample
Summary of Results (all Ps<0.05 unless otherwise reported):
- Mean weight change ranged between 1.88 to 2.66 kg (3.96 to 5.85 lbs) for men and 2.06 to 2.98 kg (4.56 to 6.56 lb) in women.
- In women, mean baseline BMI, triceps skinfold, suscapular skinfold, and plasma cholesterol, decreased with increasing baseline frequency of eating occasions (P<0.006).
- In men, mean baseline BMI and subscapular skinfold decreased with increasing baseline eating frequency; trends in triceps skinfold and plasma cholesterol were not consistent.
- Mean dietary energy and alcohol intake increased with increasing baseline eating frequency in both men and women.
- At follow-up, the highest eating frequency category (>6/d) was associated with largest mean weight change and baseline BMI in women, but not men.
- Mean plasma cholesterol at baseline was inversely associated with frequency of eating at follow-up in women but not men.
- Mean plasma cholesterol measured at baseline was inversely associated with frequency of eating at follow-up in women but not men.
- For every unit increase in frequency of eating at baseline, men and women gained 0.22 kg (.48 lbs) (P=0.03) and 0.34 kg (.75 lbs) (P=0.0002) of body weight, respectively, over the period of follow-up. After adjustment for age, and other confounders, this relationship was no longer significant.
- Re-analyzing data excluding persons reporting being on a special diet did not change the pattern of results.
There was no independent association of frequency of food ingestion estimated from a 24-h dietary recall with prospective weight change or frequency of eating estimated from answers to questions on number of meals and snacks consumed daily with weight change over the preceding 8-10 years in the NHEFS cohort.
|Government:||National Cancer Institute|
|University/Hospital:||Queens College of City University of New York|
Quality Criteria Checklist: Primary Research
|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)||Yes|
|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?||???|
|2.2.||Were criteria applied equally to all study groups?||N/A|
|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?||N/A|
|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%.)||No|
|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?||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?||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?||Yes|
|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?||No|
|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?||No|
|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?||No|
|7.5.||Was the measurement of effect at an appropriate level of precision?||No|
|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?||No|
|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|