Turek · Science (New York, N.Y.) 2005 · controlled animal experiment · n=?

Obesity and metabolic syndrome in circadian Clock mutant mice.

Cited 2496 times in the scientific literature.

Level 5 - mechanism / opinion, no new human data

Preclinical animal study in mice

PubMed 15845877 · doi:10.1126/science.1108750 · record verified 2026-08-30

What was done

Researchers evaluated feeding behavior, metabolic markers, and hypothalamic peptide gene expression in homozygous Clock mutant mice.

What was found

The abstract reports no numerical values. Homozygous Clock mutant mice exhibited an attenuated diurnal feeding rhythm, hyperphagia, and obesity. They developed metabolic syndrome characterized by hyperleptinemia, hyperlipidemia, hepatic steatosis, hyperglycemia, and hypoinsulinemia, along with attenuated hypothalamic expression of peptides involved in energy balance.

Why it matters

This study demonstrates a direct genetic link between the molecular circadian clock network and metabolic homeostasis in mammals.

Limits

The study was conducted entirely in an animal model, which may not directly translate to human physiology. The abstract provides no sample sizes, numerical data, or effect sizes.

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