Study analysis · The American journal of clinical nutrition · 1993
You can build muscle while losing 16 kg — even on a starvation-level diet.
Women who lifted weights while eating very little got stronger muscles, even though they lost a lot of weight.
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 compared two groups of women who lost a lot of weight — one lifted weights and one didn’t. The ones who lifted weights gained some muscle, but we can’t be 100% sure it was because of the weights because we don’t know if the researchers made sure no one knew who was in which group. So it’s a hint, not a proof.
What’s the bottom line?
People on a very low-calorie diet lost a lot of weight, but those who lifted weights also grew stronger muscles.
How strong is this study?
The study tried to be fair by randomly putting people in groups, which is good. But it only had 14 people, and we don’t know if the people measuring the muscles knew who lifted weights — that could mess up the results. So it’s a decent start, but not super trustworthy without more info.
0 / 100
- COI disclosureconflicts of interest not disclosed
- Data availabilitydata not shared
- Code availabilitycode not shared
58 / 100
- Randomization+20/20
- Blindingblinding unclear
- Control group+15/15
- Sample size (n=14)+1.4/20
- Follow-up+10/10
100 / 100
0 / 100
- P-valuesno p-values reported
- 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 540 / 100
Probability of being correct
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
This design can establish causation. Randomization is explicitly stated in the abstract, allowing for causal inference despite lack of blinding information; however, small sample size and lack of blinding details reduce confidence.
No Conflicts
No conflicts of interest identified
No conflicts of interest or funding information were disclosed in the provided text.
The study lacks any disclosure of funding sources, author affiliations, or conflicts of interest. While the results appear methodologically sound, the absence of transparency raises potential concerns about undisclosed biases.
Key takeaways
- 01
16 kg weight loss total; muscle fibers got bigger only in people who did weight training.
- 02
Yes — even when eating very little, lifting weights can make muscles grow bigger, not just shrink.
Surprising findings
- Muscle fiber cross-sectional area increased in the resistance training group despite 16 kg total weight loss and only 24% of that loss coming from fat-free mass.It contradicts the common belief that severe calorie restriction inevitably causes muscle breakdown — here, muscle grew even as fat was lost rapidly.
Practical takeaways
If you're on a very low-calorie diet, include resistance training to preserve or even build muscle.
This study used a very small sample (n=14), no statistical details were provided, and results may not apply to men, non-obese individuals, or longer durations.
low confidenceWhy this study matters
Muscle Growth on a Starvation Diet
Fourteen obese women lost an average of 16 kg over 90 days on a 3360-kJ/day liquid diet. Only those who did resistance training saw significant increases in both slow-twitch and fast-twitch muscle fiber size in their thighs.
Most people assume you lose muscle when dieting hard — this shows muscle growth is possible even under extreme calorie restriction, if you train.
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
People on a very low-calorie diet lost a lot of weight, but those who lifted weights also grew stronger muscles.
Research results
16 kg weight loss total; muscle fibers got bigger only in people who did weight training.
What this means - more context
Yes — even when eating very little, lifting weights can make muscles grow bigger, not just shrink.
To determine whether muscle hypertrophy is possible during severe weight loss.
Fourteen obese females underwent a 3360-kJ/day liquid diet for 90 days; half performed resistance training. Both groups lost 16 kg on average, with 76% from fat. Only the resistance training group showed significant increases in slow-twitch and fast-twitch muscle fiber cross-sectional area.
Methods Used
Randomized controlled trial with 14 obese females; 7 assigned to weight training, 7 sedentary; muscle biopsies from vastus lateralis taken at baseline and after 90 days of a 3360-kJ/day liquid diet.
Main Finding
The cross-sectional area of slow-twitch and fast-twitch muscle fibers significantly increased in the weight training group despite 16 kg total weight loss; no change occurred in the sedentary group.
Confidence Level
Limited - based on abstract only, full methodology not available
Study Flags
Red Flags
- •Full text not available - methodology details cannot be verified
- •No effect sizes or p-values reported in abstract
- •Small sample size (n=14) with no statistical details provided
Surprising Findings
Muscle fiber cross-sectional area increased in the resistance training group despite 16 kg total weight loss and only 24% of that loss coming from fat-free mass.
It contradicts the common belief that severe calorie restriction inevitably causes muscle breakdown — here, muscle grew even as fat was lost rapidly.
Practical Takeaways
If you're on a very low-calorie diet, include resistance training to preserve or even build muscle.
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 540 / 100
Probability of being correct
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
Human RCT
Subject
Moderate probability
on the GRADE evidence scale
This study compared two groups of women who lost a lot of weight — one lifted weights and one didn’t. The ones who lifted weights gained some muscle, but we can’t be 100% sure it was because of the weights because we don’t know if the researchers made sure no one knew who was in which group. So it’s a hint, not a proof.
No conflicts of interest were detected in this study. No score impact.
Strengths
- Randomized controlled design explicitly stated
- Direct muscle biopsy measurement of hypertrophy
- Clear intervention and control group comparison
Weaknesses
- Sample size is very small (n=14)
- Blinding status unknown — risk of performance and detection bias
- Full methodology not available - based on abstract only
Methodology
Evidence Keywords
Statistical Reporting
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
People on a very low-calorie diet lost a lot of weight, but those who lifted weights also grew stronger muscles.
Research results
16 kg weight loss total; muscle fibers got bigger only in people who did weight training.
What this means - more context
Yes — even when eating very little, lifting weights can make muscles grow bigger, not just shrink.
To determine whether muscle hypertrophy is possible during severe weight loss.
Fourteen obese females underwent a 3360-kJ/day liquid diet for 90 days; half performed resistance training. Both groups lost 16 kg on average, with 76% from fat. Only the resistance training group showed significant increases in slow-twitch and fast-twitch muscle fiber cross-sectional area.
Methods Used
Randomized controlled trial with 14 obese females; 7 assigned to weight training, 7 sedentary; muscle biopsies from vastus lateralis taken at baseline and after 90 days of a 3360-kJ/day liquid diet.
Main Finding
The cross-sectional area of slow-twitch and fast-twitch muscle fibers significantly increased in the weight training group despite 16 kg total weight loss; no change occurred in the sedentary group.
Confidence Level
Limited - based on abstract only, full methodology not available
Study Flags
Red Flags
- •Full text not available - methodology details cannot be verified
- •No effect sizes or p-values reported in abstract
- •Small sample size (n=14) with no statistical details provided
Surprising Findings
Muscle fiber cross-sectional area increased in the resistance training group despite 16 kg total weight loss and only 24% of that loss coming from fat-free mass.
It contradicts the common belief that severe calorie restriction inevitably causes muscle breakdown — here, muscle grew even as fat was lost rapidly.
Practical Takeaways
If you're on a very low-calorie diet, include resistance training to preserve or even build muscle.
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 540 / 100
Probability of being correct
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
Human RCT
Subject
Moderate probability
on the GRADE evidence scale
This study compared two groups of women who lost a lot of weight — one lifted weights and one didn’t. The ones who lifted weights gained some muscle, but we can’t be 100% sure it was because of the weights because we don’t know if the researchers made sure no one knew who was in which group. So it’s a hint, not a proof.
No conflicts of interest were detected in this study. No score impact.
Strengths
- Randomized controlled design explicitly stated
- Direct muscle biopsy measurement of hypertrophy
- Clear intervention and control group comparison
Weaknesses
- Sample size is very small (n=14)
- Blinding status unknown — risk of performance and detection bias
- Full methodology not available - based on abstract only
Methodology
Evidence Keywords
Statistical Reporting
Scoring
How strong is this study?
The study tried to be fair by randomly putting people in groups, which is good. But it only had 14 people, and we don’t know if the people measuring the muscles knew who lifted weights — that could mess up the results. So it’s a decent start, but not super trustworthy without more info.
0 / 100
- COI disclosureconflicts of interest not disclosed
- Data availabilitydata not shared
- Code availabilitycode not shared
58 / 100
- Randomization+20/20
- Blindingblinding unclear
- Control group+15/15
- Sample size (n=14)+1.4/20
- Follow-up+10/10
100 / 100
0 / 100
- P-valuesno p-values reported
- 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 540 / 100
Probability of being correct
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
This design can establish causation. Randomization is explicitly stated in the abstract, allowing for causal inference despite lack of blinding information; however, small sample size and lack of blinding details reduce confidence.
No Conflicts
No conflicts of interest identified
No conflicts of interest or funding information were disclosed in the provided text.
The study lacks any disclosure of funding sources, author affiliations, or conflicts of interest. While the results appear methodologically sound, the absence of transparency raises potential concerns about undisclosed biases.
Standing
Who’s using this study?
The videos and claims on this site that lean on this study, and the researchers who wrote it.
2 videos from 2 different creators cite this study, drawing 2 claims from it.
- Very strong evidence
Randomized or controlled trials support this claim, alongside consistent supporting evidence.
Evidence
- Good evidence
Good evidence supports this claim, with little to contradict it.
Evidence