The claimEvidence B · meta-analysis
I'm a night owl, so staying up costs me nothing
The evidence
Chronotype is heritable (Jones 2019, 351 loci), but being innately late ≠ staying up is free. Greater social jet lag tracks higher BMI in the overweight (Roenneberg 2012). Sleep enough, aligned to your rhythm.
The mechanism, in brief
The earlier scenes covered the cost of an all-nighter; this scene goes back to the source: why do people stay up late? Partly innate rhythm, partly behavioral habit — and the two must be told apart.
Sources (2)
- Jones, S. E., Lane, J. M., Wood, A. R., van Hees, V. T., Tyrrell, J., Beaumont, R. N., et al. (2019). Genome-wide association analyses of chronotype in 697,828 individuals provides insights into circadian rhythms. Nature Communications, 10, 343. Identified 351 loci associated with morningness, confirming chronotype is substantially heritable; the most morning-leaning carriers slept ~25 min earlier.
- Roenneberg, T., Allebrandt, K. V., Merrow, M., & Vetter, C. (2012). Social jetlag and obesity. Current Biology, 22(10), 939-943. The mismatch between biological and social clocks (social jetlag) was positively associated with higher BMI among the overweight, linking circadian misalignment to weight.