AWM: Eating Frequency and Patterns (2013)


Morse SA, Ciechanowski PS, Katon WJ, Hirsch IB. Isn't this just bedtime snacking? The potential adverse effects of night-eating symptoms on treatment adherence and outcomes in patients with diabetes. Diabetes Care 2006; 29 (8): 1,800-1,804.

PubMed ID: 1687383
Study Design:
Cross-Sectional Study
D - Click here for explanation of classification scheme.
Quality Rating:
Neutral NEUTRAL: See Quality Criteria Checklist below.
Research Purpose:

To examine night-eating symptoms and diabetes care management strategies of patients with type 1 or type 2 diabetes.

Inclusion Criteria:

Eligible participants included all patients at the Diabetes Care Center at the University of Washington who met the following criteria: 

  • Aged ≥ 18 years
  • English speaking
  • Who had at least two clinic appointments, the most recent within the past six months.
Exclusion Criteria:

Patients with severe cognitive or language deficits which might prevent them from reasoning and communication were excluded.

Description of Study Protocol:


  • Potential subjects were sent an approach letter briefly describing the study
  • Two weeks later, subjects received a questionnaire and consent form that fully explained the study and requested permission for a review of automated medical records
  • A reminder letter, consent form and duplicate questionnaire were sent to nonrespondents after three weeks.


Cross-sectional study

Blinding used

Not applicable 


Not applicable 

Statistical Analysis

  • X2 analyses and two-tailed t-tests were used to examine differences between night-eating symptom groups (presence or absence of night eating symptoms) on baseline demographic, clinical and psychosocial characteristics
  • To determine whether the presence of night-eating symptoms was associated with A1C greater than 7%, obesity [BMI (body mass index) >30kg/m2] or having two or more diabetes complications, three logistic regression analyses were conducted and controlled for potential confounders that also showed differences between night-eating symptoms groups bivariate analysis.
Data Collection Summary:

Timing of Measurements

Measurements completed in April 2003.

Dependent Variables

  • Psychosocial Characteristics
    • Major depression
    • Emotional eating triggers including: Anger, sadness, loneliness, worry, being upset
    • Childhood Trauma Questionnaire including: Family was a source of strength, frightened of being hurt, someone in family hated individual, sexual abuse, sexual coercion, physical abuse, parental neglect
    • Non-secure attachment style
  • A1C levels
  • Prevalence of obesity
  • Prevalence of diabetes complications, including: Retinopathy, neuropathy, nephropathy, cardiovascular disease (CVD), peripheral vascular disease (PVD).

Independent Variables

  • Night Eating Symptoms classified as individuals who consumed >25% of their daily intake after suppertime
  • Clinical Characteristics:
    • Type 1 or 2 diabetes
    • Smoking status
    • Use of insulin
    • Use of oral hypoglycemic medications
    • Medical comorbidity
    • Treatment adherence including: Diet, exercise, glucose monitoring, foot care
    • Diabetes duration
    • Sleep disturbance
    • Total number of diabetes symptoms.

Control Variables

  • Sex
  • Race
  • Marital status
  • Education
  • Age.
Description of Actual Data Sample:
  • Initial N: 1,583 patients
  • Attrition (final N): 714 patients responded to the survey (45%)
  • Age:
    • 18-39; 33.9%
    • 40-56; 32.6%
    • Age ≥57; 33.5%
  • Ethnicity: 88.5% Caucasian
  • Other relevant demographics:
    • 88.7% had at least one year of college
    • 65.5% were married or living as married
  • Anthropometrics: 32.1% had BMI >30kg/m2
  • Location: Seattle, Washington, USA.


Summary of Results:

Key Findings

  • Among respondents to the survey, 69, (9.7%) reported having night-eating symptoms
  • Those with night-eating symptoms were younger, were less likely to be married or living as married (x2=6.34) and were less likely to be Caucasian (x2=8.61)   
  • Compared with patients without night-eating symptoms, those with night-eating symptoms were significantly less likely to be adherent with diet (x2=4.91), exercise (x2=2.61) and glucose monitoring (x2=4.39); reported significantly more sleep disturbance (x2=14.5) and diabetes symptoms (x2=4.64 ) and were significantly more likely to report having neuropathy (x2=4.71).
  • Compared with patients without night-eating symptoms, those with night-eating symptoms were significantly more likely to have major depression (x2=8.83), to eat in response to emotions [anger (x2=11.7), sadness (x2=7.17), loneliness (x2=17.66), worry (x2=19.21), or being upset (x2=7.63)] and to report childhood maltreatment [sexual abuse (x2=10.19 ) and coercion (x2=11.16), physical abuse (x2=9.27) or parental neglect (x2=11.27)] and were more likely to have a non-secure attachment style (x2=5.32).
  • Logistic regression models controlling for age, sex, race and major depression status demonstrated that compared with patients without night-eating symptoms, those with night-eating symptoms were significantly more likely to have A1C values >7% (odds ratio 2.2 [95% CI 1.1-4.1]) to obese (2.6 [1.5-4.5]) and to have two or more diabetes complications (2.6 [1.5-4.5]). 


Author Conclusion:

In evaluating 714 participants with type 1 and 2 diabetes in a large tertiary care clinic, 9.7% of patients reported eating >25% of their daily food intake after their evening meal. In this large sample, a single questionnaire item about nocturnal food intake discriminated patients who had significantly more depression, childhood maltreatment and maladaptive interpersonal interactions and who reported eating in response to commonly experienced emotional triggers. 

In examining patients with night-eating syndrome (NES) and those without, there was no difference in the proportion of subjects who used insulin which can stimulate the appetite vs. those who did not. The results also indicated a significant association between night-eating symptoms and obesity, elevated A1C and number of complications. Caution in interpreting these cross-sectional results is required, but these findings suggest that adverse diabetes self-management and outcomes may be associated with night-eating behaviors.

Funding Source:
Government: National Institute of Diabetes and Digestive and Kidney Diseases Grant
Reviewer Comments:

The authors note the following limitations:

  • The cross-sectional nature of the study and the fact that only a single, albeit cardinal item for screening for night-eating behaviors was used
  • In this population based study, questions from diagnostic questionnaires or from proposed NES criteria were not used to establish what is currently determined to be NES
  • Also, although this tertiary care sample was large, the results may not be generalizable to diabetic patients in primary care
  • The response rate was 45% and it was not possible to characterize non-respondents demographically or clinically other than by age and sex.
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) Yes
Validity Questions
1. Was the research question clearly stated? ???
  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? ???
  1.3. Were the target population and setting specified? Yes
2. Was the selection of study subjects/patients free from bias? ???
  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? ???
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? No
  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? 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? 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? 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? 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