Many individuals experience increased appetite and specific food cravings in the days leading up to their menstrual period. This phenomenon, often attributed to premenstrual syndrome (PMS), is not simply “in your head.” It is rooted in a complex interplay of hormonal shifts, metabolic changes, and neurochemical responses within the body. Understanding these scientific reasons can validate these experiences and provide insight into the body’s natural processes.
The Hormonal Rollercoaster
Key drivers behind increased hunger during the premenstrual phase are fluctuating levels of estrogen and progesterone. Estrogen acts as an appetite suppressant and mood booster. Conversely, progesterone stimulates appetite. During the luteal phase, which begins after ovulation and extends until menstruation, progesterone levels rise significantly. Estrogen levels, though initially high, decline closer to the period. This shift, with progesterone becoming more prevalent as estrogen falls, contributes to increased hunger.
Hormonal changes also influence leptin and ghrelin, two hormones regulating hunger and satiety. Progesterone stimulates ghrelin, the “hunger hormone,” making you feel hungrier. It also reduces leptin, the “satiety hormone,” meaning you may not feel full as quickly. This combined effect of elevated progesterone and declining estrogen promotes increased food intake and cravings.
Metabolic Shifts and Energy Demands
Beyond hormonal influences, the body’s metabolism undergoes subtle changes in the premenstrual phase, contributing to increased hunger. The basal metabolic rate (BMR), the energy your body requires at rest, can increase during the luteal phase, sometimes by 10% to 20%. This heightened metabolic activity means the body burns more calories, even at rest, increasing its energy demands.
This increased energy expenditure prompts the body to seek more fuel. Studies suggest that during the luteal phase, the body may require an additional 100 to 300 calories per day. While this caloric increase might seem minor, it often triggers a noticeable increase in appetite and a desire for more food. The body’s preparation for a potential pregnancy, even if one does not occur, also contributes to this heightened demand for nutrients.
The Brain-Gut Connection and Cravings
Specific food cravings before a period, such as for carbohydrates and sugary foods, are linked to the brain’s neurochemistry. Hormonal fluctuations affect neurotransmitters like serotonin, which plays a significant role in mood, sleep, and appetite regulation. Serotonin levels decrease in the days leading up to menstruation.
When serotonin levels are low, the body instinctively seeks foods that boost this “feel-good” chemical. Carbohydrates, particularly simple sugars, temporarily increase serotonin production in the brain, leading to a transient mood improvement. This physiological response explains why comfort foods rich in carbohydrates and sugars become appealing. The gut microbiota, also influencing brain chemistry, can be affected by hormonal changes, further impacting cravings.
Psychological and Emotional Influences
While physiological factors are primary, psychological and emotional elements also contribute to increased hunger and specific food choices during the premenstrual period. Premenstrual symptoms often include mood swings, irritability, stress, anxiety, and fatigue. These uncomfortable emotional states can lead to emotional eating, where food is consumed as a coping mechanism for distress, not physical hunger.
Seeking comfort through food is a natural response to these emotional challenges. The temporary mood boost from certain foods, especially those high in sugar and carbohydrates, can create a cycle where emotional discomfort drives food choices, providing fleeting relief. The increased appetite before a period is a multifaceted phenomenon, combining genuine physiological needs with psychological responses to premenstrual discomfort.