Unintended Weight Loss in Older Adults

UWL: Association With Outcomes (2009)

Citation:

de Castro JM. Age-related changes in the social, psychological and temporal influences on food intake in free-living, healthy, adult humans. J Gerontol A Biol Sci Med Sci. 2002; 57 (6): M368-M377.

PubMed ID: 12023266
 
Study Design:
Cross-sectional study
Class:
D - Click here for explanation of classification scheme.
Quality Rating:
Neutral NEUTRAL: See Quality Criteria Checklist below.
Research Purpose:

To study the influences of non-physiological factors on the nutrient intakes of the elderly and to investigate age-related changes in the eating behaviors of free-living humans.

Inclusion Criteria:

None specifically mentioned.

Exclusion Criteria:

None specifically mentioned.

Description of Study Protocol:

Recruitment

  • Data were collected from 762 participants, who were paid $30 for their participation.
  • Recruitment methods not described.

Design

  • Cross-sectional study
  • Seven-day diet diary records had been collected from participants and reanalyzed.

Statistical Analysis

  • Participants were separated into four age groups: 20 to 34 years, 35 to 49 years, 50 to 64 years and 65 years and older
  • For each participant, Pearson product moment correlations and regression slopes between a number of variables and the meal sizes were calculated individually
  • Correlations were calculated for each participant, correlation coefficients were transformed to Z-scores
  • Mean correlations and coefficients were then compared to zero with a T-test.
Data Collection Summary:

Timing of Measurements

Diet diary nutrient intake data were collected for a seven-day period from free-living adult humans.

Dependent Variables

Dietary intake was measured through a seven-day diet diary and nutritionally analyzed.

Independent Variables

  • Self-ratings were obtained at the beginning and at the end of the meal of the participants' degrees of hunger, thirst, depression, anxiety and the attractiveness of the food on seven-point scales
  • Demographic information, including age, weight, height, medications taken, occupation, living arrangements (alone or with others), and exercise habits, was collected
  • Three Factor Eating Questionnaire was administered to measure dietary restraint, disinhibition and hunger, but only the Cognitive Restraint Scale scores were used in the analysis
  • Diurnal rhythms investigated, as well as the influence of the day of the week on intake.
Description of Actual Data Sample:

Initial N

762 paid participants: 348 men and 414 women.

Attrition (Final N)

As above.

Age

  • 20 to 34 years: 114 men, 211 women
  • 35 to 49 years: 154 men, 138 women
  • 50 to 64 years: 54 men, 45 women
  • 65 years and older: 26 men, 20 women

Ethnicity

Not mentioned.

Location

Georgia.

Summary of Results:

Other Findings

  • There was an overall significant difference between the number of other people present at the meals (P<0.05), with the elderly group eating with significantly fewer people present than the 35- to 49-year-old group (P<0.05)
  • The before-meal hunger self-ratings significantly differed between age groups (P<0.05), with the elderly group having significantly lower ratings than either the 20- to 34- or 35- to 49-year-old groups (both P<0.05)
  • The after-meal hunger self-ratings significantly differed between age groups (P<0.05), with the elderly group having significantly lower hunger (higher satiety) ratings than all of the other three groups (all P<0.05)
  • The youngest age group ate significantly later than all of the other groups (all P<0.05) and the elderly and 50- to 64-year-old groups ate significantly earlier than either the youngest group or the 35- to 49-year-old group (both P<0.05)
  • Intake on weekends was significantly higher than on weekdays (P<0.05), but the elderly do not appear to have as large a difference between weekday and weekend intake as do younger groups
  • The elderly were found to be as responsive as younger groups to social facilitation of intake, palatability, cognitive restraint, day of week and location.
Author Conclusion:

In summary, although there is much evidence that the elderly have deficiencies in the physiological systems that influence intake in younger people, the present findings indicate that the elderly are very responsive to social, psychological and environmental stimuli. Hence, there does not appear to be a decline with age in the ability of non-physiological factors to influence the nutrient intakes of the elderly. This suggests that the deficient intakes in the elderly might be corrected or ameliorated by manipulation of non-physiological factors, such as the number of other people present at meals, the palatability of meals and the time of day and location of meals. It remains for future manipulative studies to test this hypothesis.

Funding Source:
University/Hospital: Georgia State University Research Program Enhancement Grant
Reviewer Comments:
  • Recruitment methods and inclusion and exclusion criteria were not described
  • Authors note that the diet diary technique is a self-report methodology that is not absolutely accurate.
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? ???
  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? No
  2.2. Were criteria applied equally to all study groups? No
  2.3. Were health, demographics, and other characteristics of subjects described? No
  2.4. Were the subjects/patients a representative sample of the relevant population? ???
3. Were study groups comparable? ???
  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? ???
  3.3. Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.) ???
  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? ???
  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.) ???
  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? 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? 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? 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? 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