Adults should aim for 7-9 hours of sleep per night, ideally before 11 p.m., to support brain recovery, strengthen immunity, and optimize metabolic functions. Healthline indicates that prolonged late nights and insufficient sleep disrupt the hormones regulating hunger and fullness, leading to increased cravings for calorie-dense foods.

The gut-brain axis connects the stomach and the brain. Ghrelin, known as the "hunger hormone", is released from the stomach. This hormone signals the brain about when to eat and when to shift from burning calories to storing them as fat. Normally, ghrelin levels decrease after meals and stay low during sleep. However, staying up late or getting inadequate sleep results in elevated ghrelin levels.

Conversely, leptin, often called the "satiety hormone", is vital for appetite and weight control. Released by fat cells, leptin crosses the blood-brain barrier to signal fullness. It also helps stimulate fat burning to produce energy.

Leptin levels naturally rise after meals and remain elevated during sleep, boosting metabolism until waking. Consequently, insufficient sleep lowers leptin, preventing the brain from receiving satiety signals. This condition, known as leptin resistance, indicates a metabolic disorder and raises the risk of obesity and metabolic syndrome.

Hunger and satiety hormones affect eating behavior. Illustration created by AI.

Staying up late diminishes insulin sensitivity and elevates cortisol, the stress hormone. This combination often results in consuming more energy-dense foods and accumulating abdominal fat.

Sleep profoundly impacts the prefrontal cortex, the brain region responsible for emotional regulation. Inadequate sleep often results in fatigue and stress, with eating sometimes becoming a coping mechanism for these psychological states, contributing to weight gain. Furthermore, poor sleep quality depletes energy, making adults less inclined to be physically active or engage in sufficient exercise, which can lead to weight gain, as reported by EveryDay Health.

Moreover, poor sleep deprives organs of essential rest and recovery, diminishing the effectiveness of workouts. This prolonged effect can lead to weight gain and metabolic disorders.

Staying up late negatively impacts the body's blood sugar regulation by decreasing insulin sensitivity. This often prompts the body to produce more insulin to maintain normal blood sugar levels, a pattern that can elevate the risk of type 2 diabetes and contribute to weight gain.

To enhance sleep quality, individuals should maintain a consistent sleep schedule, aiming to go to bed and wake up at similar times daily. Incorporate relaxing activities before sleep, such as reading, taking a warm bath, performing gentle stretches, or listening to calming music.

Additionally, limit screen time from phones, laptops, and televisions before bed. Avoid caffeine and alcohol in the evening. Creating a dark, quiet, and cool bedroom environment can also significantly improve sleep quality.

By Anh Chi