Is nutritional status endangered by virtually no extra intake during pregnancy?

In the course of a multinational study on energy requirements in pregnancy and lactation, the food intake of 67 pregnant women in Glasgow was measured by the use of the individual weighed inventory technique, for 3 or 5 consecutive days every 6 weeks (in 21 women), every 4 weeks (in 23 women), or every 2 weeks (in 23 women). Data were obtained in the pre-pregnant state in 12 women. Rises in energy intakes were small and gradual in the first 34 weeks of pregnancy, the mean being about 50 kcal (210 kJ)/day, but in the remaining weeks of pregnancy, intakes rose by about 150 kcal (630 kJ)/day. The total extra energy intake therefore represented less than 20 000 kcal (84 MJ), as opposed to theoretical estimates of requirements of 80 000 kcal (335 MJ). Energy-saving mechanisms may have resulted in reductions in physical activity, but this was not obvious in the study population. However, there was depression of basal metabolic rates in the first half of pregnancy, which could produce considerable energy savings.