Appetite changes are an expected and normal part of pregnancy, representing a physiological response to profound hormonal and metabolic shifts. These changes drive the need for increased nourishment to support fetal development and prepare the maternal body for birth. While the experience of hunger is highly individualized, it generally follows a pattern tied to the three trimesters of gestation and the body’s changing energy demands.
Initial Appetite Shifts: The First Trimester Paradox
For many, the initial weeks of pregnancy present a paradox: energy requirements begin to change, but the subjective feeling of hunger often decreases or remains flat. The rapid rise of human chorionic gonadotropin (hCG) is largely responsible for this effect. Elevated hCG levels are closely linked to common symptoms like nausea, vomiting, and intense food aversions, often called morning sickness. These uncomfortable symptoms effectively suppress the desire to eat, causing a temporary loss of appetite. Since the fetus is still microscopic, the body does not yet require a substantial increase in daily calories during this initial stage.
Appetite Rises in the Second Trimester
The most significant and consistent increase in appetite typically begins during the second trimester, often starting around week 13 to 14. This period marks the end of the first trimester’s hormonal peaks, leading to the resolution of nausea and food aversions for most individuals. The decline in hCG levels and the stabilization of other hormones allow natural hunger signals to return. The physiological need for increased energy becomes substantial as the fetus enters a phase of rapid growth and development. The maternal body must support the baby’s increasing size, the growth of the placenta, and an expansion of blood volume, which translates into an increased appetite requiring an average of about 300 to 350 additional calories per day.
Peak Calorie Needs: Appetite in the Third Trimester
While the body’s caloric requirements are highest in the final trimester, demanding up to 450 to 500 extra calories daily, the actual sensation of hunger can become erratic or decrease. The reason for this change is mechanical rather than hormonal. As the uterus expands to its maximum size, it crowds the abdominal cavity, placing considerable pressure on the stomach. This compression significantly reduces the stomach’s capacity, meaning the feeling of fullness is reached much faster. To meet the high energy demands for peak fetal growth, many must shift to consuming smaller, more frequent meals throughout the day.