What causes a plateau in fat loss?

The consumption of a hypocaloric diet and consequent fat loss lead to alterations in circulating levels of hormones that regulate hunger and satiety, which signals nutrient deprivation to the brain and results in increased hunger and food cravings as well as decreased satiety.^[1] Alongside these physiological nudges to increase energy intake, total daily energy expenditure decreases with weight loss. This occurs for a variety of reasons, including reduced sympathetic nervous system activity, lower circulating levels of leptin and thyroid hormone, and increased skeletal muscle and mitochondrial efficiency. As a result of these changes, incremental decreases in energy intake are often needed over time to produce further fat loss.^[2]