Jorn Trommelen, PhD
@jorntrommelen.bsky.social
Assistant professor. Muscle Metabolism.
Follow @jorntrommelen.bsky.social for more evidence-based threads on exercise, nutrition and metabolism.
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Do carrots increase skin attractiveness?
What is more attractive?
✅ Low vs carotenoid-rich skin
✅ Low vs melanin-rich ("tanned") skin
✅ Carotenoid-rich vs melanin-rich skin
Let's break it down!
1/11
What is more attractive?
✅ Low vs carotenoid-rich skin
✅ Low vs melanin-rich ("tanned") skin
✅ Carotenoid-rich vs melanin-rich skin
Let's break it down!
1/11
December 16, 2025 at 3:38 PM
Follow @jorntrommelen.bsky.social for more evidence-based threads on exercise, nutrition and metabolism.
Please like and share the first tweet linked below to help spread the word:
bsky.app/profile/jorn...
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Conclusion:
Skin with higher carotenoid levels is most attractive, melanin-rich skin shows moderate preference, and low-carotenoid skin is the least attractive.
Link to study:
pubmed.ncbi.nlm.nih.gov/25014019/
11/11
Skin with higher carotenoid levels is most attractive, melanin-rich skin shows moderate preference, and low-carotenoid skin is the least attractive.
Link to study:
pubmed.ncbi.nlm.nih.gov/25014019/
11/11
December 16, 2025 at 3:36 PM
Conclusion:
Skin with higher carotenoid levels is most attractive, melanin-rich skin shows moderate preference, and low-carotenoid skin is the least attractive.
Link to study:
pubmed.ncbi.nlm.nih.gov/25014019/
11/11
Skin with higher carotenoid levels is most attractive, melanin-rich skin shows moderate preference, and low-carotenoid skin is the least attractive.
Link to study:
pubmed.ncbi.nlm.nih.gov/25014019/
11/11
Finally, the participants were predominately white, the experiment was conducted in the UK, and cultural differences may influence results.
10/11
10/11
December 16, 2025 at 3:36 PM
Finally, the participants were predominately white, the experiment was conducted in the UK, and cultural differences may influence results.
10/11
10/11
Limitations
The carotenoid skin tone tested represented an “optimal” hue from pilot testing. It is unclear whether more extreme carotenoid tones would be equally attractive or less attractive.
9/11
The carotenoid skin tone tested represented an “optimal” hue from pilot testing. It is unclear whether more extreme carotenoid tones would be equally attractive or less attractive.
9/11
December 16, 2025 at 3:36 PM
Limitations
The carotenoid skin tone tested represented an “optimal” hue from pilot testing. It is unclear whether more extreme carotenoid tones would be equally attractive or less attractive.
9/11
The carotenoid skin tone tested represented an “optimal” hue from pilot testing. It is unclear whether more extreme carotenoid tones would be equally attractive or less attractive.
9/11
Interpretation
Pale skin may signal lower health, while tanning may partially mimic the visual effect of carotenoids or mask a low carotenoid status.
8/11
Pale skin may signal lower health, while tanning may partially mimic the visual effect of carotenoids or mask a low carotenoid status.
8/11
December 16, 2025 at 3:36 PM
Interpretation
Pale skin may signal lower health, while tanning may partially mimic the visual effect of carotenoids or mask a low carotenoid status.
8/11
Pale skin may signal lower health, while tanning may partially mimic the visual effect of carotenoids or mask a low carotenoid status.
8/11
Experiment 3:
Carotenoid-rich skin was preferred over high-melanin skin (~76%).
7/11
Carotenoid-rich skin was preferred over high-melanin skin (~76%).
7/11
December 16, 2025 at 3:36 PM
Experiment 3:
Carotenoid-rich skin was preferred over high-melanin skin (~76%).
7/11
Carotenoid-rich skin was preferred over high-melanin skin (~76%).
7/11
Experiment 2:
Melanin-rich (“tanned”) skin was preferred over low-carotenoid skin (~79%).
6/11
Melanin-rich (“tanned”) skin was preferred over low-carotenoid skin (~79%).
6/11
December 16, 2025 at 3:36 PM
Experiment 2:
Melanin-rich (“tanned”) skin was preferred over low-carotenoid skin (~79%).
6/11
Melanin-rich (“tanned”) skin was preferred over low-carotenoid skin (~79%).
6/11
Participants indicated which face variant they found more attractive.
Experiment 1:
Carotenoid-rich skin was preferred over low-carotenoid skin (~86%).
5/11
Experiment 1:
Carotenoid-rich skin was preferred over low-carotenoid skin (~86%).
5/11
December 16, 2025 at 3:36 PM
Participants indicated which face variant they found more attractive.
Experiment 1:
Carotenoid-rich skin was preferred over low-carotenoid skin (~86%).
5/11
Experiment 1:
Carotenoid-rich skin was preferred over low-carotenoid skin (~86%).
5/11
This study used software to create controlled versions of the same faces, differing only in skin color:
➡️ higher or lower carotenoid-related yellowness
➡️ higher or lower melanin-related darkness
4/11
➡️ higher or lower carotenoid-related yellowness
➡️ higher or lower melanin-related darkness
4/11
December 16, 2025 at 3:36 PM
This study used software to create controlled versions of the same faces, differing only in skin color:
➡️ higher or lower carotenoid-related yellowness
➡️ higher or lower melanin-related darkness
4/11
➡️ higher or lower carotenoid-related yellowness
➡️ higher or lower melanin-related darkness
4/11
Researchers call this effect “increased skin yellowness”, informally better known as a “carrot tan”.
A carrot tan is consistently rated as attractive, possibly because it signals current health and micronutrient status.
3/11
A carrot tan is consistently rated as attractive, possibly because it signals current health and micronutrient status.
3/11
December 16, 2025 at 3:36 PM
Researchers call this effect “increased skin yellowness”, informally better known as a “carrot tan”.
A carrot tan is consistently rated as attractive, possibly because it signals current health and micronutrient status.
3/11
A carrot tan is consistently rated as attractive, possibly because it signals current health and micronutrient status.
3/11
Carrots get their orange color from beta-carotene.
When consumed, beta-carotene is absorbed and accumulates in the skin and subcutaneous fat, giving the skin a yellow-gold tone.
2/11
When consumed, beta-carotene is absorbed and accumulates in the skin and subcutaneous fat, giving the skin a yellow-gold tone.
2/11
December 16, 2025 at 3:36 PM
Carrots get their orange color from beta-carotene.
When consumed, beta-carotene is absorbed and accumulates in the skin and subcutaneous fat, giving the skin a yellow-gold tone.
2/11
When consumed, beta-carotene is absorbed and accumulates in the skin and subcutaneous fat, giving the skin a yellow-gold tone.
2/11
Follow @jorntrommelen.bsky.social for more evidence-based threads on exercise, nutrition and metabolism.
Please like and share the first tweet linked below to help spread the word:
bsky.app/profile/jorn...
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Does a higher resistance exercise volume stimulate MPS more?
✅ 1 set vs 3 sets
✅ Early vs late MPS
✅ Within-subject design
Let’s break it down!
1/11
@mackinprof.bsky.social
✅ 1 set vs 3 sets
✅ Early vs late MPS
✅ Within-subject design
Let’s break it down!
1/11
@mackinprof.bsky.social
December 9, 2025 at 10:34 AM
Follow @jorntrommelen.bsky.social for more evidence-based threads on exercise, nutrition and metabolism.
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In conclusion:
a greater resistance exercise volume results in a higher and more prolonged stimulation of muscle protein synthesis.
Link to study:
pubmed.ncbi.nlm.nih.gov/20581041/
11/11
a greater resistance exercise volume results in a higher and more prolonged stimulation of muscle protein synthesis.
Link to study:
pubmed.ncbi.nlm.nih.gov/20581041/
11/11
December 9, 2025 at 10:33 AM
In conclusion:
a greater resistance exercise volume results in a higher and more prolonged stimulation of muscle protein synthesis.
Link to study:
pubmed.ncbi.nlm.nih.gov/20581041/
11/11
a greater resistance exercise volume results in a higher and more prolonged stimulation of muscle protein synthesis.
Link to study:
pubmed.ncbi.nlm.nih.gov/20581041/
11/11
A limitation is that muscle protein breakdown was not measured, even though it may also increase with a higher training volume.
10/11
10/11
December 9, 2025 at 10:33 AM
A limitation is that muscle protein breakdown was not measured, even though it may also increase with a higher training volume.
10/11
10/11
A strength of this work is the unilateral study design, which enables a direct within-participant comparison of 1 vs 3 sets, thereby minimizing influences of genetic and motivational factors.
9/11
9/11
December 9, 2025 at 10:33 AM
A strength of this work is the unilateral study design, which enables a direct within-participant comparison of 1 vs 3 sets, thereby minimizing influences of genetic and motivational factors.
9/11
9/11
This suggests that resistance training volume (number of sets) is an important driver for muscle growth and that very low volumes may be suboptimal.
8/11
8/11
December 9, 2025 at 10:33 AM
This suggests that resistance training volume (number of sets) is an important driver for muscle growth and that very low volumes may be suboptimal.
8/11
8/11
Interpretation?
Even a single set of resistance exercise results in a clear increase in MPS.
However, three sets elicit a greater and longer-lasting MPS response.
7/11
Even a single set of resistance exercise results in a clear increase in MPS.
However, three sets elicit a greater and longer-lasting MPS response.
7/11
December 9, 2025 at 10:33 AM
Interpretation?
Even a single set of resistance exercise results in a clear increase in MPS.
However, three sets elicit a greater and longer-lasting MPS response.
7/11
Even a single set of resistance exercise results in a clear increase in MPS.
However, three sets elicit a greater and longer-lasting MPS response.
7/11
Key findings:
• Three sets produced a greater rise in early-phase MPS than one set.
• The next day, MPS remained elevated in the three-set treatment, whereas it had returned to baseline in the one-set treatment.
6/11
• Three sets produced a greater rise in early-phase MPS than one set.
• The next day, MPS remained elevated in the three-set treatment, whereas it had returned to baseline in the one-set treatment.
6/11
December 9, 2025 at 10:33 AM
Key findings:
• Three sets produced a greater rise in early-phase MPS than one set.
• The next day, MPS remained elevated in the three-set treatment, whereas it had returned to baseline in the one-set treatment.
6/11
• Three sets produced a greater rise in early-phase MPS than one set.
• The next day, MPS remained elevated in the three-set treatment, whereas it had returned to baseline in the one-set treatment.
6/11
MPS was measured in the early phase (first 5 hours post-exercise) and the next day (24-29 hours postexercise).
5/11
5/11
December 9, 2025 at 10:33 AM
MPS was measured in the early phase (first 5 hours post-exercise) and the next day (24-29 hours postexercise).
5/11
5/11
Resistance-trained males performed a unilateral exercise protocol in which each leg completed a different condition, randomly assigned to:
• 1 set unilateral leg extensions to failure
• 3 sets of unilateral leg extensions to failure
4/11
• 1 set unilateral leg extensions to failure
• 3 sets of unilateral leg extensions to failure
4/11
December 9, 2025 at 10:33 AM
Resistance-trained males performed a unilateral exercise protocol in which each leg completed a different condition, randomly assigned to:
• 1 set unilateral leg extensions to failure
• 3 sets of unilateral leg extensions to failure
4/11
• 1 set unilateral leg extensions to failure
• 3 sets of unilateral leg extensions to failure
4/11
This study investigated the effect of resistance exercise volume on muscle protein synthesis (MPS; the process driving muscle adaptations such as growth).
3/11
3/11
December 9, 2025 at 10:33 AM
This study investigated the effect of resistance exercise volume on muscle protein synthesis (MPS; the process driving muscle adaptations such as growth).
3/11
3/11
Some training philosophies, such as High-Intensity Training (HIT), propose that one set taken to failure is enough to maximize muscle growth.
Others have suggested that more sets always produce more gains.
2/11
Others have suggested that more sets always produce more gains.
2/11
December 9, 2025 at 10:33 AM
Some training philosophies, such as High-Intensity Training (HIT), propose that one set taken to failure is enough to maximize muscle growth.
Others have suggested that more sets always produce more gains.
2/11
Others have suggested that more sets always produce more gains.
2/11
November 21, 2025 at 2:10 PM