When calorie intake drops drastically, the body undergoes significant hormonal changes that affect both appetite and metabolism. One of the main hormones involved is ghrelin, known as the “hunger hormone.” As calorie consumption decreases, ghrelin levels rise, sending strong hunger signals to the brain and making it difficult to resist eating. At the same time, levels of leptin, the hormone responsible for signaling fullness and satiety, decline. This imbalance causes persistent feelings of hunger even when the body still has adequate energy reserves stored as fat.
These hormonal shifts also lead to a slowdown in basal metabolic rate (BMR)—the amount of energy the body uses at rest to maintain vital functions. When the metabolism slows, the body becomes more energy-efficient, conserving calories and burning less fat. Although this is a natural survival mechanism designed to protect against starvation, it makes weight loss increasingly challenging. Consequently, despite eating less, individuals may find their progress plateauing or even experience weight regain over time. This complex hormonal response demonstrates how extreme calorie restriction can backfire, emphasizing the importance of balanced, sustainable dietary approaches for effective and long-term weight management.
