Intended for healthcare professionals

Research Article

Reduction in postprandial energy expenditure during pregnancy.

Br Med J (Clin Res Ed) 1987; 294 doi: (Published 20 June 1987) Cite this as: Br Med J (Clin Res Ed) 1987;294:1573
  1. P J Illingworth,
  2. R T Jung,
  3. P W Howie,
  4. T E Isles


    Energy expenditure was measured during pregnancy in seven primigravid women at 12-15, 25-28, and 34-36 weeks and after the cessation of lactation. On each occasion the resting metabolic rate and the increase in metabolic rate after ingestion of a liquid test meal were measured by indirect calorimetry. In absolute terms the resting metabolic rate increased steadily during pregnancy but when expressed per unit of body weight no change was found. The energetic response to a mixed constituent meal was significantly reduced by 28% in the middle trimester of pregnancy. These findings suggest a possible maternal adaptation to increase energetic efficiency at a time when the energy demands of the fetus are high.