Blue Light and Weight

Blue light from phone screens, computers, and LED lighting at night can disrupt your body’s internal clock and contribute to weight gain. Exposure to blue light in the evening suppresses melatonin — the sleep hormone — which can lead to poorer sleep quality, increased late-night snacking, and metabolic changes that favour weight gain.

Evening blue light exposure (wavelengths 380-500 nm) suppresses pineal melatonin secretion via melanopsin-containing intrinsically photosensitive retinal ganglion cells (ipRGCs), disrupting circadian rhythms. This circadian misalignment alters cortisol rhythms, reduces insulin sensitivity, increases ghrelin-to-leptin ratio, and shifts food intake toward later hours — all of which independently promote weight gain and metabolic dysfunction.

Simple habits like reducing screen time an hour before bed, using night-mode settings, or wearing blue-light-blocking glasses in the evening can improve sleep quality and support your weight management efforts. At Accord Medical, Dr Joseph Wang takes a holistic approach that addresses all factors affecting your weight — including sleep and screen habits.