Skipping breakfast every day tricks your body into thinking it's always in starvation mode, which keeps stress hormones high and messes up your natural sleep-wake cycle.
Scientific Claim
Chronic daily breakfast skipping leads to persistent low-calorie intake and misaligned cortisol rhythms, impairing circadian entrainment to environmental light cues.
Original Statement
“So if you're consistently skipping breakfast, you're running into a few problems. One, you're consistently keeping your calories low and at the same amount every day so that your body's just adjusted to skipping breakfast. Two, you're consistently bumping your cortisol spikes and crashes to unnatural times because you're consistently skipping meals, which means your body is never getting a chance to calibrate with the light cues the way that you would think it would.”
Context Details
Domain
lifestyle
Population
human
Subject
Chronic daily breakfast skipping
Action
leads to
Target
persistent low-calorie intake and misaligned cortisol rhythms impairing circadian entrainment to light cues
Intervention Details
Evidence from Studies
Supporting (2)
When pregnant women skipped breakfast, their stress hormone (cortisol) and sleep hormone (melatonin) rhythms got messed up—exactly what the claim says happens when you skip breakfast every day.
Technical explanation
This study directly links breakfast skipping to altered cortisol and melatonin rhythms in humans, which are central to circadian entrainment. It measures the exact outcomes (cortisol rhythm disruption) from the exact intervention (breakfast skipping) in a human cohort, making it highly relevant to the assertion.
Skipping breakfast made rats' internal body clocks get out of sync, especially for how their liver handles fat and hormones—just like the claim says it messes up our body’s daily rhythm.
Technical explanation
This paper directly tests breakfast skipping (via delayed first meal) and demonstrates disrupted circadian rhythms in hepatic clock genes and metabolic hormones, aligning with the assertion's claim that breakfast skipping misaligns cortisol rhythms and impairs circadian entrainment. Although conducted in rats on a high-fat diet, the core mechanism—breakfast skipping disrupting circadian entrainment—is directly relevant.
Contradicting (1)
Association of Skipping Breakfast with Metabolic Syndrome and Its Components: A Systematic Review and Meta-Analysis of Observational Studies
This study says skipping breakfast is linked to health problems like obesity and high blood pressure, but it doesn’t look at whether it messes up your body’s internal clock or hormone levels, so it can’t confirm the claim.