What is the main dietary advantage of butter lettuce being generally recognized as low in calories during pregnancy?

It helps manage necessary but controlled weight gain

Managing weight gain within established healthy parameters is an important aspect of prenatal care. Butter lettuce contributes positively to this management strategy because it is inherently low in caloric content relative to its volume. This characteristic allows expectant mothers to consume nutrient-dense, satisfying portions of greens without significantly contributing to overall caloric surplus. By choosing lighter options like butter lettuce, mothers can reserve appetite and caloric allowance for other more energy-dense components of their diet that supply elevated needs for macronutrients and specific micronutrients like iron or folate, thus facilitating controlled weight management.