How does poor sleep affect your weight and metabolism?

Poor sleep disrupts the hormones that regulate hunger and appetite. It raises ghrelin, the hormone that signals hunger, while lowering leptin, which signals fullness. This combination makes you feel hungrier and less satisfied after eating, leading to increased calorie consumption, particularly from high-fat and high-sugar foods. Sleep deprivation also impairs insulin sensitivity, meaning your body becomes less efficient at processing glucose, which raises the risk of fat storage and type 2 diabetes. Your resting metabolic rate can also slow slightly with chronic poor sleep. Additionally, fatigue reduces physical activity and motivation to exercise. Over time, these combined effects create conditions that strongly favor weight gain and metabolic dysfunction, even without major changes in diet.