Light brightness changes how light disrupts daily rhythms and affects sugar and fat metabolism in mice

The circadian-disrupting light cycle increased body weight gain and insulin resistance in mice fed a high-fat diet under high light intensity conditions.

• Circadian disruption is associated with increased body weight gain and adipocyte area in mice on both low-fat and high-fat diets under high light intensity.
• Glucose intolerance and insulin resistance were observed in high-fat diet mice exposed to the circadian-disrupting light cycle at high light intensity.
• Higher triglyceride levels in serum and liver were noted in mice on a low-fat diet when exposed to high light intensity, regardless of the light cycle.
• The negative metabolic effects of the circadian-disrupting light cycle were alleviated when mice were exposed to lower light intensity, particularly in those on a high-fat diet.
• The interaction of light intensity and light cycle on metabolism occurs independently of dietary energy intake and eating patterns.

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