光照时间影响减脂效率？Cell子刊新发现：冬季白昼缩短，居然能无声促进脂肪燃烧！

Core Insights - The article discusses the impact of seasonal light exposure on body weight regulation, highlighting that shorter daylight in winter can lead to weight loss and fat reduction due to changes in energy metabolism and eating patterns [6][11]. Group 1: Mechanisms of Light Exposure on Weight Management - Short daylight activates the body's "fat-burning switch," leading to lower body weight and fat mass in mice exposed to winter-like conditions, with a significant reduction in liver triglyceride levels by approximately 20% [11]. - The study indicates that light exposure influences eating rhythms, where mice in long daylight conditions exhibit disrupted lipid metabolism, while those in short daylight conditions have enhanced fat oxidation and reduced fat synthesis [12]. - Contrary to previous beliefs, melatonin was found not to be the key regulator of seasonal metabolism, as the fat-reducing effects of short daylight persisted even in the absence of melatonin [13]. Group 2: Scientific Evidence Supporting Light-Related Fat Loss - Short daylight alters the circadian rhythms of metabolic genes in peripheral tissues, delaying the peak expression of lipid metabolism-related genes by about 4 hours, which affects fat synthesis and breakdown [14]. - Mice in short daylight conditions showed a higher respiratory exchange ratio (RER), indicating increased carbohydrate utilization and enhanced fat oxidation, with a rhythmic increase in non-esterified fatty acids (NEFA) in the plasma [15]. - Time-restricted feeding (TRF) mimicking short daylight conditions resulted in similar metabolic indicators as those observed in short daylight mice, suggesting that limiting eating times can effectively simulate the fat loss benefits of reduced light exposure [16].