Unintended Weight Loss in Older Adults

UWL: Medical Nutrition Therapy (2007)


Mamhidir AG, Ljundggren G, Kihlgren M, Kihlgren A, Wimo A. Underweight, weight loss and related risk factors among older adults in sheltered housing: A Swedish follow-up study. J Nutr Health Aging. 2006; 10(4): 255-262.

PubMed ID: 16886095
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 describe underweight, weight loss and related nutritional factors after 12 months among individuals 75 years or older and living in sheltered housing 
  • To identify possible risk factors associated with underweight and weight loss.
Inclusion Criteria:
  • Adults age 75 or older, permanently living in community-run sheltered housing units.
  • Sheltered housing units consisted of nursing homes, group living facilities for persons with dementia disease and service houses where the older adults resided in individual apartments.
Exclusion Criteria:

Those who do not fit the inclusion criteria.

Description of Study Protocol:


800 individuals from 24 sheltered housing units were recruited from a survey in 1999 from Gavleborg County in Sweden. Sujects were randomly selected from the survey results.


Cross-sectional study. The RAI/MDS version two was used to capture core elements that are necessary for comprehensive assessment of older adults receiving health care. The main elements used as signals of malnutrition were underweight and weight loss. Caregivers of the residents performed two assessments within a 12-month interval. A Cognitive Performance Scale to assess cognitive capacity and the Depression Rating Scale to assess for depression was also done. 

Statistical Analysis

Descriptive statistics, Student's independent T-test, Chi-square test, McNemar Test, Student's paired T-test and multiple stepwise logistic regression were used with a P-value less than 0.05 considered significant. 

Data Collection Summary:

Timing of Measurements

Data were collected twice, with a 12-month interval between measurements, using the Resident Assessment Instrument (RAI/MDS), using the categories of underweight and weight loss as signals indicating malnutrition.  

Dependent Variables

  • Underweight status: BMI less than 22 kg/m2
  • Significant weight loss: Five percent to 10% of body weight lost over a one-year period. 

Independent Variables

  • The single items used from the RAI/MDS were: Age, gender, vision problems, eating dependency, constipation, heart failure, hip fracture, stroke, dementia, Parkinson's disease, cancer, chewing and swallowing disorders, mouth pain, complaints about the taste of the food, hunger, often leaves 25% of food uneaten, intake of dietary supplements between meals, dental status, number of medications taken within the last seven days and if certain medications are prescribed
  • Cognitive function was measured with the Cognitive Performance Scale
  • The Depression Rating Scale was used to measure for depression
  • The Activities of Daily Living (ADL) score was also measured to assess for independence and dependence in ADLs.  


Description of Actual Data Sample:
  • Initial N: 800 were recruited. 719 were included
  • Attrition (final N): 503. Of the 216 subjects that did not complete the study, 184 subjects passed away during the study (26%), 14 (2%) moved away and 18 (2%) of the assessments were not completed.  
  • Age: Average age of the initial group was 85.8±5.6 years, which was not significantly different from the group at one-year follow-up of 86.2±5.5 years
  • Ethnicity: Was not specified. This study did take place in Sweden. 
  • Other relevant demographics: 36% had dementia
  • Location: Multiple sheltered housing locations in Gavleborg County in central Sweden. 
Summary of Results:



Significant Nutrition-related Factors According to RAI/MDS at Two Occasions with a One-year Interval (N=503)


At start N (%)

After One Year N (%) P- value
Moderately or highly impaired vision 125 (25) 159 (32) <0.0001
Cognitive Performance Scale (CPS scale zero to one) 195 (39) 178 (35) <0.0001
Physical abuse 32 (6) 38 (8) 0.010
Advanced ADL dependency (ADL score four to nine) 313 (62) 278 (55) <0.0001

Unable to sit up without help

Fell in previous 31 to 180 days

89 (18)

112 (22)

117 (23)

84 (17)



Independent in eating assistance 346 (69) 299 (60) <0.0001


Changes in Weight and BMI Assessed According to the RAI/MDS at Baseline and One-year Follow-up

   At Start N (%)

 At One-year Follow-up N (%)

 Weight (kg) (mean ±SD)  64.2±14.3  63.3±14.6  0.002
 BMI (kg/m2) (mean ±SD)  24.1±4.8  23.8±4.9  0.009
 BMI less than 22   172 (35)  176 (38)  NS
 BMI more than 30  52 (11)  51 (11)  NS



Strongest Risk Factors Predicting Risk for Underweight and Weight Loss of 5% or 10% According to Age, Gender and Different RAI-MDS Items after One Year in the Final Study Group (N=503) as Measured by 95% CI.

Predictive factors for 95% CI:


Odds Ratio Lower Upper P-value
Cognitive capacity, CPS-scale 1.844 1.267 2.683 0.001
Functional capacity, ADL-score 1.793 1.163 2.765 0.008
Age 1.038 1.001 1.077 0.045
Constipation 2.490 1.185 4.964 0.015
Parkinson's Disease 2.450 1.006 5.965 0.047
Eating dependency 2.257 1.676 3.038 0.001
Dementia 2.139 1.343 3.407 0.001

Other Findings

  • Weight at baseline was 64.2±4.3kg. At one-year follow-up, average weight was 63.3±14.6kg (P<0.002).
  • Average BMI at baseline was 24.1±4.8kg/m2. At one-year follow-up, average BMI was 23.8±4.9 (P<0.009).
  • 35% of those who remained in the study were underweight at the first assessment, which did not change significantly by follow-up
  • Over a one-year period, 27% of patients maintained stable weights, 28% gained weight and 39% lost weight
  • Of those 39% that lost weight: 27% of these patients had a weight loss of 5% of their body weight, while 14% had a weight loss of at least 10% of their initial body weight
  • Significantly lower average BMI (22.6±4.9) was found among those patients who passed away, and a significantly higher percentage of them had been underweight (46%)
  • Impaired cognitive and functional capacities were the strongest risk factors associated with being underweight and having a weight loss of 5% or 10% when using age, gender and the three scales incorporated in RAI/MDS as independent variables in logistic regression
  • Having Parkinson's disease, dementia, being eating-dependent and having constipation were the most influential risk factors for being underweight or having a 5% or 10% weight loss when analyzed as single independent variables. 
Author Conclusion:

A high percentage was underweight or exhibited weight loss and several risk factors were identified. Increased combined efforts from all levels of elder care and wider-ranged multidisciplinary nutritional programs need to implemented as well as regular routines for assessing weight loss, BMI and nutrition-related problems cannot be stressed enough.

Funding Source:
Government: Ministry of Health and Social Affairs, the Swedish Association of Local Authorities in Gavlebord, FoU-Forum in Gavleborg County Council, Frimurarelogen Gevalias in Gavle.
University/Hospital: Primary Health Care of Halsingland.
Reviewer Comments:

26% of subjects passed away during the study. Authors note that the study took place in sheltered housing units, and that the definition is not always clear, leading to a lack of distinction.

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) 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? ???
  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? 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? 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? 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? No
  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? Yes
  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? No
  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? 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? N/A
  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