Define Energy needs during pregnancy Period?

Two factors determine energy requirements: increase in mother's basal metabolism to support the work required for foetal growth and accessory tissues and changes in the mother's usual physical activity. The estimated total (cumulative) additional cost of energy is 55,000 Kcal. It works out to be an additional 300 Kcal per day in the last two trimesters. Refer to Table for Recommended Nutrient Intakes for pregnancy. Note: During the first trimester the additional energy required is small, hence the RDA is not increased

FAO/WHO/UNU 2004 recommendation for the extra energy cost of pregnancy is 85 Kcal/day, 285 Kcal/day and 475 Kcal/day during the first, second and third trimesters, respectively. There are many societies with a high proportion of non-obese women who do not seek prenatal advice before the second or third month of pregnancy.  Under these circumstances, FAO/WHO (2004) recommends that in such societies pregnant women increase their food intake by 360 Kcal/day in the second trimester and by 475 Kcal/day in the third.