Diminution in energy expenditure during lactation

• Published in: British Medical Journal (Clinical research ed.) Vol. 292; no. 6518; pp. 437 - 441
• Main Authors: Illingworth, P J, Jung, R T, Howie, P W, Leslie, P, Isles, T E
• Format: Journal Article
• Language: English
• Published: England British Medical Journal Publishing Group 15.02.1986; British Medical Association; BMJ Publishing Group LTD
• Subjects: Adult; basal metabolism; Bottle Feeding; Breastfeeding; Brown adipose tissue; energy expenditure; Energy Intake; Energy Metabolism - drug effects; Female; human lactation; Humans; Insulin; Lactation; Metabolism; Nonesterified fatty acids; Norepinephrine; Norepinephrine - pharmacology; nutrient requirements; Postpartum Period; Pregnancy; Test meals; Thermogenesis
• ISSN: 0267-0623; 1468-5833
• DOI: 10.1136/bmj.292.6518.437

Energy expenditure at rest and in response to a meal and to an infusion of noradrenaline was measured in 12 lactating women and compared with that in seven bottle feeding women and seven non-pregnant, non-lactating controls. The energy response of the lactating women was remeasured after lactation stopped. During lactation the resting metabolic rate was unaltered but there was a reduced response to infusion of noradrenaline and to a meal, which increased to normal control values after lactation stopped. Such reductions in expenditure were not found in women who had been bottle feeding and were tested at a similar six to eight weeks post partum. These findings suggest that metabolic efficiency is enhanced in lactating women, who may not need to increase energy intake to the extent suggested by current recommended dietary allowances.