Nutritionist Nmami Agarwal explains that a 1-2 kg weight gain before a woman's period is typically due to water retention caused by rising estrogen and progesterone levels. Hormonal shifts also slow digestion, leading to bloating, while dropping serotonin can affect mood and cravings. Agarwal emphasizes this weight gain is not fat and advises against drastic measures like skipping meals or intense workouts. Instead, she recommends maintaining regular meals, staying hydrated, and engaging in gentle movement like walking or stretching to manage pre-period symptoms.