Unintended Weight Loss in Older Adults

UWL: Food, Appetite and Environment (2009)


Young KWH, Greenwood CE, van Reekum R, Binns MA. A randomized, crossover trial of high-carbohydrate foods in nursing home residents with Alzheimer's disease:  associations among intervention response, body mass index, and behavioral and cognitive function. J Gerontol A Biol Sci Med Sci. 2005; 60 (8): 1,039-1,045.

PubMed ID: 16127110
Study Design:
Randomized crossover trial
A - Click here for explanation of classification scheme.
Quality Rating:
Neutral NEUTRAL: See Quality Criteria Checklist below.
Research Purpose:
  • To evaluate the effect of replacing the "traditional" dinner with carbohydrate on overall food intake in nursing home residents with Alzheimer's disease
  • To identify participant characteristics, such as carbohydrate preference, BMI, cognitive and behavioral function and the presence of behavioral problems, that were associated with intervention response.
Inclusion Criteria:

Nursing home residents with probable Alzheimer's disease who ate independently.

Exclusion Criteria:
  • Diseases requiring nutritional intervention
  • Prescription of an energy-restricted diet
  • Swallowing difficulties requiring texture-modified foods
  • Unplanned weight loss (loss of 10% or more during the six months before start of study or 5% or more during previous month)
  • Acute illness.
Description of Study Protocol:
  • Recruitment: Residents of the Alzheimer's Disease units of Baycrest Centre for Geriatric Care nursing home, a kosher facility.
  • Design: Randomized crossover trial.
  • Blinding used: Non-blinded.


  • Replacing 12 non-consecutive "traditional" dinners with meals high in carbohydrate, but comparable to traditional dinners in protein
  • Four phases, each lasting 21 days
    • Phase One: Usual diet
    • Phase Two: Random assignment to high-carbohydrate dinner or mid-morning nutrition supplement intervention
    • Phase Three: Usual diet washout period
    • Phase Four: Received opposite treatment.

Statistical Analysis

  • Power analysis required 28 participants
  • Mean intervention vs. baseline energy, protein, fat and carbohydrate, were compared using the Student's T-test at both the group level and for each participant
  • Comparisons limited to days having dairy dinners
  • Habitual macronutrient preference calculated during baseline phase
  • Several regression approaches and factor analysis completed.
Data Collection Summary:

Timing of Measurements

Four phases, each lasting 21 days. Body weight measured on Day One and on the last day of every phase.

Dependent Variables

  • Weighed food intake
  • Body weight and BMI
  • Cognitive function assessed using the Severe Impairment Battery and Global Deterioration Scale
  • Behavioral disturbances assessed using the Neuropsychiatric Inventory-Nursing Home Version
  • Behavioral function assessed using the London Psychogeriatric Rating Scale.

Independent Variables

  • "Traditional" dinners vs. meals high in carbohydrate, but comparable in protein
  • All foods served to participants were weighed before and after consumption and converted to nutrient intake using software program.
Description of Actual Data Sample:
  • Initial N: 34 residents, 27 women, seven men
  • Attrition (final N): 32 residents; two dropped out due to acute illness.
  • Age: 88.2±3.9 years
  • Ethnicity: Not mentioned
  • Anthropometrics: Crossover study; no significant differences in subjects during different study phases
  • Location: Canada.
Summary of Results:

Other Findings

  • Group mean dinner and 24-hour energy intake increased during the intervention phase compared with baseline, protein and fat intake was unaffected and carbohydrate intake increased
  • Group mean intake was increased 119.4±115.5kcal at dinner (P<0.001) and 109.6±141.8kcal over 24 hours (P<0.001).  There were no changes at other meals.
  • Increased dinner intake, attributable to intervention foods, was achieved in 20 of 32 participants and was associated with increased carbohydrate preference, poorer memory and increased aberrant motor behavior
  • Those with low BMI were the most resistant to the intervention
  • There were no significant changes in body weight during the intervention (increase of 0.36±1.12kg, P=0.076) possibly because of the short intervention period.
Author Conclusion:

Providing a high-carbohydrate meal for dinner increases food intake in seniors at later stages of the disease who are experiencing cognitive and behavioral difficulties, possibly as a result of a shift in preference for high-carbohydrate foods.

Funding Source:
Reviewer Comments:
  • Mid-morning nutrition supplement described elsewhere
  • Only residents from one nursing home, small sample size
  • Kosher meals may have complicated the intervention
  • Authors note that further studies evaluating the long-term response to the intervention are needed, as well as the limited generalizability of results.
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? 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? 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? N/A
  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.) N/A
  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? Yes
  5.1. In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate? No
  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? 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? ???
  6.1. In RCT or other intervention trial, were protocols described for all regimens studied? No
  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? ???
  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? No
  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? Yes
  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? ???
  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? 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