Study analysis · The Journal of Nutrition, Health & Aging · 2021
Even active grandmothers gained weight and lost muscle function during lockdown—but their grip strength stayed the same.
A small study of physically active elderly women in Brazil found that after one year of lockdown, they gained 3% more body weight and twice as many had muscle function problems.
Overview
What the study found
The study in plain English — the bottom line, every takeaway we extracted, and what to do with them.
In simple terms
This study is like following a group of elderly women for a year during the pandemic and noticing they gained weight and got weaker. But because there was no other group to compare them to, we can't be sure that the lockdown itself caused these changes. It could be that they would have changed anyway, or something else was responsible. So the study gives us a hint, but not proof.
What’s the bottom line?
Scientists followed 29 active grandmothers in Brazil. Before the pandemic, they were active. Then lockdown stopped their activities. After one year, they had gained weight, and more of them had trouble with muscle function.
How strong is this study?
This study was small (only 29 women) and didn't have a comparison group, so it's like a weak test. Also, they didn't check what the women ate or did at home, which could have affected the results. Because of these problems, we shouldn't fully trust the findings until bigger and better studies are done.
40 / 100
- COI disclosure+40/40
- Data availabilitydata not shared
- Code availabilitycode not shared
16 / 100
- Randomizationnot randomized
- Blindingnot blinded
- Control groupno control group
- Sample size (n=29)+2.7/20
- Follow-up+10/10
100 / 100
23 / 100
- P-values+15/15
- Effect sizeno effect size reported
- Confidence intervalsno confidence intervals
- Pre-registrationnot pre-registered
Each component is scored out of 100 and then capped by the study design — a case series cannot reach the ceiling a randomised trial can, however well it is reported.
Where it sits
RCT reviewsReviews of RCTs (Meta-analyses)
Max 100Randomized TrialsRandomized Trials
Max 90Reviews of Cohort StudiesReviews of Cohort Studies
Max 85Cohort StudiesCohort Studies
Max 72Reviews of Case-Control StudiesReviews of Case-Control Studies
Max 63Case-Control StudiesCase-Control Studies
Max 58Cross-Sectional & Case SeriesCross-Sectional & Case Series
Max 50Expert OpinionExpert Opinion
Max 539 / 100
Probability of being correct
Groups of people are followed over time to see who develops an outcome. Strong for identifying risk factors and associations, but cannot prove causation as firmly as RCTs.
This design cannot establish causation — the findings describe an association, not a cause. This is an observational cohort study without a control group. It only measures changes over time in a single group, so it cannot isolate the effect of lockdown from other confounding factors (e.g., diet, lifestyle changes, aging). Causation cannot be established; only associations can be reported.
No Conflicts
No conflicts of interest identified
No conflicts of interest identified; authors declare no competing interests.
The study does not mention any funding source. The conflict of interest section explicitly states no conflicts.
Key takeaways
- 01
On average, they gained 3% more body weight.
- 02
The number with muscle function loss went from about 14% to 28%.
- 03
A 3% weight gain for a 65-year-old woman of average weight (63 kg) is about 1.9 kg.
- 04
That's noticeable but not huge.
- 05
The doubling of muscle function loss is concerning, but handgrip strength didn't change, so muscle strength was preserved.
Surprising findings
- Handgrip strength did not change significantly despite a doubling in self-reported muscle function loss.Common sense would expect both to decline with inactivity, but objective strength was preserved while functional complaints increased.
Practical takeaways
Seniors should incorporate at-home resistance training and protein-rich meals to maintain muscle function during periods of reduced activity.
This study didn't test interventions; the tip is based on general sarcopenia prevention guidelines.
low confidenceMonitor self-reported muscle function (e.g., SARC-F questionnaire) as an early indicator of decline, even if grip strength seems fine.
SARC-F is a screening tool, not a diagnostic. Follow up with a professional if concerns arise.
low confidenceWhy this study matters
Lockdown Weight Gain in Active Seniors
Among 29 physically active elderly women (mean age 65.5) in Brazil, average body weight increased by 3.0% (p=0.002) over one year of lockdown. For a typical 63 kg woman, that's about 1.9 kg (4.2 lbs).
This shows that even those who were active before lockdown were not immune to weight gain when forced to stay home.
Muscle Function Loss Doubled
The prevalence of muscle function loss (SARC-F ≥4) jumped from 13.8% to 27.6%—a doubling. Yet handgrip strength, a measure of muscle strength, did not change significantly (21.2 vs 21.0 kg, p=0.77).
This suggests that self-reported function declines before objective strength loss, which could be an early warning sign for sarcopenia.
Small Study, Big Implications
With only 29 participants and no control group, the study's confidence is low. Yet it's one of the first to measure muscle function loss in Brazilian elderly during the pandemic.
Despite limitations, the findings highlight a real-world problem that larger studies should confirm.
Want the whole report?
Detailed mode opens the full scientific breakdown — every score component, the methodology, conflicts of interest, the evidence analysis behind each claim, and the raw study data.
Overview
What the study found
The study in plain English — the bottom line, every takeaway we extracted, and what to do with them.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Scientists followed 29 active grandmothers in Brazil. Before the pandemic, they were active. Then lockdown stopped their activities. After one year, they had gained weight, and more of them had trouble with muscle function.
Research results
On average, they gained 3% more body weight. The number with muscle function loss went from about 14% to 28%.
What this means - more context
A 3% weight gain for a 65-year-old woman of average weight (63 kg) is about 1.9 kg. That's noticeable but not huge. The doubling of muscle function loss is concerning, but handgrip strength didn't change, so muscle strength was preserved.
To assess the consequences of physical inactivity due to COVID-19 lockdown on body weight and muscle function loss in physically active elderly women.
In a cohort of 29 physically active Brazilian elderly women, one year of lockdown led to a significant 3.0% increase in body weight (p=0.002) and a doubling of muscle function loss prevalence (SARC-F≥4 from 13.8% to 27.6%). Handgrip strength did not change significantly.
Methods Used
Cohort study; 29 physically active elderly women (mean age 65.5 years) assessed before (Dec 2019) and after one year of lockdown (Jan 2021). Body weight, BMI, handgrip strength, and SARC-F questionnaire were measured.
Main Finding
Body weight increased by an average of 3.0% and muscle function loss prevalence doubled from 13.8% to 27.6% over one year of lockdown.
Confidence Level
Low: small sample size (n=29), no control group, observational design, and no adjustments for confounders.
Study Flags
Red Flags
- •Very small sample size (n=29)
- •No control group
- •No adjustment for diet or lifestyle changes
No biological mechanisms were identified in this study. This may be an epidemiological, observational, or survey-based study that reports associations rather than proposing causal biological pathways.
Surprising Findings
Handgrip strength did not change significantly despite a doubling in self-reported muscle function loss.
Common sense would expect both to decline with inactivity, but objective strength was preserved while functional complaints increased.
Practical Takeaways
Seniors should incorporate at-home resistance training and protein-rich meals to maintain muscle function during periods of reduced activity.
RCT reviewsReviews of RCTs (Meta-analyses)
Max 100Randomized TrialsRandomized Trials
Max 90Reviews of Cohort StudiesReviews of Cohort Studies
Max 85Cohort StudiesCohort Studies
Max 72Reviews of Case-Control StudiesReviews of Case-Control Studies
Max 63Case-Control StudiesCase-Control Studies
Max 58Cross-Sectional & Case SeriesCross-Sectional & Case Series
Max 50Expert OpinionExpert Opinion
Max 539 / 100
Probability of being correct
Groups of people are followed over time to see who develops an outcome. Strong for identifying risk factors and associations, but cannot prove causation as firmly as RCTs.
Human Cohort Study
Subject
Lower probability
on the GRADE evidence scale
This study is like following a group of elderly women for a year during the pandemic and noticing they gained weight and got weaker. But because there was no other group to compare them to, we can't be sure that the lockdown itself caused these changes. It could be that they would have changed anyway, or something else was responsible. So the study gives us a hint, but not proof.
No conflicts of interest were detected in this study. No score impact.
Strengths
- Prospective design with pre- and post-measurements
- Objective measurement of body weight and handgrip strength
- Use of validated SARC-F questionnaire for muscle function loss screening
Weaknesses
- No control group (lack of comparator)
- Small sample size (n=29) reduces statistical power and precision
- No blinding of outcome assessment (potential measurement bias)
Methodology
Evidence Keywords
Statistical Reporting
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Scientists followed 29 active grandmothers in Brazil. Before the pandemic, they were active. Then lockdown stopped their activities. After one year, they had gained weight, and more of them had trouble with muscle function.
Research results
On average, they gained 3% more body weight. The number with muscle function loss went from about 14% to 28%.
What this means - more context
A 3% weight gain for a 65-year-old woman of average weight (63 kg) is about 1.9 kg. That's noticeable but not huge. The doubling of muscle function loss is concerning, but handgrip strength didn't change, so muscle strength was preserved.
To assess the consequences of physical inactivity due to COVID-19 lockdown on body weight and muscle function loss in physically active elderly women.
In a cohort of 29 physically active Brazilian elderly women, one year of lockdown led to a significant 3.0% increase in body weight (p=0.002) and a doubling of muscle function loss prevalence (SARC-F≥4 from 13.8% to 27.6%). Handgrip strength did not change significantly.
Methods Used
Cohort study; 29 physically active elderly women (mean age 65.5 years) assessed before (Dec 2019) and after one year of lockdown (Jan 2021). Body weight, BMI, handgrip strength, and SARC-F questionnaire were measured.
Main Finding
Body weight increased by an average of 3.0% and muscle function loss prevalence doubled from 13.8% to 27.6% over one year of lockdown.
Confidence Level
Low: small sample size (n=29), no control group, observational design, and no adjustments for confounders.
Study Flags
Red Flags
- •Very small sample size (n=29)
- •No control group
- •No adjustment for diet or lifestyle changes
No biological mechanisms were identified in this study. This may be an epidemiological, observational, or survey-based study that reports associations rather than proposing causal biological pathways.
Surprising Findings
Handgrip strength did not change significantly despite a doubling in self-reported muscle function loss.
Common sense would expect both to decline with inactivity, but objective strength was preserved while functional complaints increased.
Practical Takeaways
Seniors should incorporate at-home resistance training and protein-rich meals to maintain muscle function during periods of reduced activity.
RCT reviewsReviews of RCTs (Meta-analyses)
Max 100Randomized TrialsRandomized Trials
Max 90Reviews of Cohort StudiesReviews of Cohort Studies
Max 85Cohort StudiesCohort Studies
Max 72Reviews of Case-Control StudiesReviews of Case-Control Studies
Max 63Case-Control StudiesCase-Control Studies
Max 58Cross-Sectional & Case SeriesCross-Sectional & Case Series
Max 50Expert OpinionExpert Opinion
Max 539 / 100
Probability of being correct
Groups of people are followed over time to see who develops an outcome. Strong for identifying risk factors and associations, but cannot prove causation as firmly as RCTs.
Human Cohort Study
Subject
Lower probability
on the GRADE evidence scale
This study is like following a group of elderly women for a year during the pandemic and noticing they gained weight and got weaker. But because there was no other group to compare them to, we can't be sure that the lockdown itself caused these changes. It could be that they would have changed anyway, or something else was responsible. So the study gives us a hint, but not proof.
No conflicts of interest were detected in this study. No score impact.
Strengths
- Prospective design with pre- and post-measurements
- Objective measurement of body weight and handgrip strength
- Use of validated SARC-F questionnaire for muscle function loss screening
Weaknesses
- No control group (lack of comparator)
- Small sample size (n=29) reduces statistical power and precision
- No blinding of outcome assessment (potential measurement bias)
Methodology
Evidence Keywords
Statistical Reporting
Scoring
How strong is this study?
This study was small (only 29 women) and didn't have a comparison group, so it's like a weak test. Also, they didn't check what the women ate or did at home, which could have affected the results. Because of these problems, we shouldn't fully trust the findings until bigger and better studies are done.
40 / 100
- COI disclosure+40/40
- Data availabilitydata not shared
- Code availabilitycode not shared
16 / 100
- Randomizationnot randomized
- Blindingnot blinded
- Control groupno control group
- Sample size (n=29)+2.7/20
- Follow-up+10/10
100 / 100
23 / 100
- P-values+15/15
- Effect sizeno effect size reported
- Confidence intervalsno confidence intervals
- Pre-registrationnot pre-registered
Each component is scored out of 100 and then capped by the study design — a case series cannot reach the ceiling a randomised trial can, however well it is reported.
Where it sits
RCT reviewsReviews of RCTs (Meta-analyses)
Max 100Randomized TrialsRandomized Trials
Max 90Reviews of Cohort StudiesReviews of Cohort Studies
Max 85Cohort StudiesCohort Studies
Max 72Reviews of Case-Control StudiesReviews of Case-Control Studies
Max 63Case-Control StudiesCase-Control Studies
Max 58Cross-Sectional & Case SeriesCross-Sectional & Case Series
Max 50Expert OpinionExpert Opinion
Max 539 / 100
Probability of being correct
Groups of people are followed over time to see who develops an outcome. Strong for identifying risk factors and associations, but cannot prove causation as firmly as RCTs.
This design cannot establish causation — the findings describe an association, not a cause. This is an observational cohort study without a control group. It only measures changes over time in a single group, so it cannot isolate the effect of lockdown from other confounding factors (e.g., diet, lifestyle changes, aging). Causation cannot be established; only associations can be reported.
No Conflicts
No conflicts of interest identified
No conflicts of interest identified; authors declare no competing interests.
The study does not mention any funding source. The conflict of interest section explicitly states no conflicts.