Combined effects of high-fat feeding and circadian desynchronization

Sep 15, 2005International journal of obesity (2005)

Combined effects of high-fat diet and disrupted daily rhythms

AI simplified

Circadian Biology on OpenScience ↗PubMed ↗DOI ↗

Abstract

Shifting the light-dark cycle weekly resulted in significant disturbances in locomotor activity among rats.

Circadian desynchronization was effectively induced by weekly shifts in the light-dark cycle.
Rats on a low-fat diet during nocturnal feeding had lower plasma insulin levels compared to those on a fixed light-dark cycle.
Blood glucose levels remained similar in both groups fed the low-fat diet.
High-fat diet consumption during nocturnal hours resulted in increased abdominal fat and elevated plasma leptin levels.
Chronic desynchronization did not significantly alter the metabolic changes caused by the high-fat diet.

AI simplified

OBJECTIVE: To assess whether circadian desynchronization leads to metabolic alterations capable of promoting dietary obesity and/or impairing glucose tolerance.

DESIGN: Rats fed either with chow pellets (i.e., low-fat diet with 4% mass of fat) or high-fat diet (34% mass of fat). Half of each diet group was exposed to a fixed light-dark cycle or to a 10-h weekly shift in the light-dark cycle from Thursday to Sunday (20 shifts). To enforce the shifted animals to be active at unusual times of the day, food was available only during the daily dark period for all groups.

RESULTS: Shifting the light-dark cycle on a weekly basis was efficient to induce circadian desynchronization, as evidenced by strong disturbances in the daily expression of locomotor activity. Shifted rats fed with a nocturnal low-fat diet had lower plasma insulin and similar blood glucose compared to rats fed with the same diet under a fixed light-dark cycle. Nocturnal high-fat feeding led to an abdominal fat overload associated with increased plasma leptin and basal glucose. These metabolic changes were not significantly modified by circadian desynchronization.

CONCLUSION: Chronic desynchronization with low-fat diet impaired insulin regulation. Metabolic changes induced by the high-fat diet were not aggravated by chronic desynchronization.

Full Text

Full text is available at the source.

View full text (PDF) ↗View full text (HTML) ↗

Combined effects of high-fat feeding and circadian desynchronization

Abstract

Full Text

You found one interesting study. We’ll send the next 7.

what lands in your inbox each week:

Recent issues from the circadian biology brief