This chapter should be cited as follows:
Di Renzo L, Glob Libr Women's Med
ISSN: 1756-2228; DOI 10.3843/GLOWM.421553
Nutrition in the Periconceptional, Pregnancy and Postpartum Periods
Volume Editor:
DOI 10.3843/GLOWM.00000
Chapter
General nutrition principles: energy balance, metabolism, anabolism and catabolism
VIDEO 2
Metabolism consists of all the chemical processes that occur in living cells. These processes/reactions can generally be classified as either anabolic (building) or catabolic (breaking down). General principles of metabolism are applied to the reproductive period and pregnancy.
Nutrition is fundamental to maintaining health, supporting metabolic processes and ensuring optimal growth and development. This presentation explores core principles of nutrition, including energy balance, metabolism and the dynamic interplay between anabolic and catabolic processes. A specific focus is placed on metabolic adaptations during pregnancy, as maternal nutrition profoundly influences fetal growth and long-term health outcomes.
Energy balance is the relationship between energy intake (from food and beverages) and energy expenditure (through basal metabolism, physical activity and thermogenesis). Maintaining energy homeostasis is essential for health, as an imbalance can lead to weight gain or loss, affecting overall metabolic function.
Metabolism consists of two fundamental pathways. Anabolism is the process involved in building complex molecules from simpler ones, requiring energy. This includes processes such as protein synthesis, glycogenesis and lipogenesis. Catabolism consists of the breakdown of complex molecules into simpler forms, releasing energy. Examples include glycolysis, lipolysis and proteolysis.
During pregnancy there are several metabolic adaptations. Pregnancy is a dynamic, anabolic state that involves significant metabolic changes to support fetal growth and maternal homeostasis. These changes can be categorized into two distinct phases. The first two trimesters are characterized by an anabolic phase, involving increased energy storage in maternal tissues through enhanced lipogenesis, heightened insulin sensitivity and greater nutrient deposition. In the third trimester, there is a catabolic phase, marked by increased lipolysis to provide energy substrates for fetal growth, accompanied by a rise in insulin resistance, leading to enhanced glucose availability for the fetus.
The placenta plays a crucial role in regulating maternal metabolism by secreting hormones that influence nutrient partitioning. These hormonal shifts ensure an adequate nutrient supply to the fetus while preparing the mother for lactation. To be sure of adequate intake, it is essential to know the woman's basal metabolic rate (BMR). BMR is a key determinant of daily energy expenditure, influenced by factors such as age, sex, body composition and hormonal status. Indirect calorimetry is considered the gold standard for measuring resting metabolic rate (RMR), providing a personalized approach to nutritional recommendations.
Moreover, maternal nutritional status and appropriate gestational weight gain are critical for preventing adverse outcomes. The fetus's body composition at birth significantly impacts long-term health. Conditions such as intrauterine growth restriction (IUGR) and small-for-gestational age (SGA) are associated with reduced fat-free mass (FFM) and fat mass (FM), predisposing individuals to metabolic diseases later in life.
Nutrient metabolism is dynamically adjusted during pregnancy to meet maternal and fetal needs. Key adjustments include macronutrient and micronutrient adaptations. In particular, an increased carbohydrate metabolism ensures a steady glucose supply to the fetus. Lipid metabolism shifts to facilitate maternal fat accumulation early in pregnancy and enhanced fat mobilization in later stages, while protein metabolism supports fetal tissue growth, placental development and maternal adaptations. Moreover, essential vitamins and minerals such as iron, folic acid, calcium and DHA (docosahexaenoic acid) play vital roles in fetal development and maternal health.
Research suggests that fetal programming, influenced by maternal nutrition, affects an individual’s risk for chronic diseases such as obesity, diabetes and cardiovascular disorders. This aligns with the Developmental Origins of Health and Disease (DOHaD) hypothesis, highlighting the importance of early nutritional intervention.
Understanding energy balance, metabolism and the specific nutritional needs during pregnancy is critical for optimizing maternal and fetal health. Ensuring adequate maternal nutrition and metabolic health contributes to positive neonatal outcomes and long-term disease prevention.
1
Summary of metabolic changes during pregnancy.
Phase | Key metabolic changes | Primary hormonal influence |
Anabolic (first and second trimesters) | Increased fat storage, enhanced insulin sensitivity, nutrient accumulation | Estrogen, progesterone, insulin |
Catabolic (third trimester) | Increased lipolysis, insulin resistance, enhanced fetal glucose uptake | Placental lactogen, cortisol |
CONFLICTS OF INTEREST
Author(s) statement awaited.
REFERENCES
De Lorenzo A, Del Gobbo V, Premrov MG, Bigioni M, Galvano F, Di Renzo L. Normal-weight obese syndrome: early inflammation? Am J Clin Nutr. 2007 Jan;85(1):40–5. doi: 10.1093/ajcn/85.1.40. PMID: 17209175. | |
Di Renzo L, Gualtieri P, Alwardat N, De Santis G, Zomparelli S, Romano L, Marchetti M, Michelin S, Capacci A, Piccioni A, Costacurta M, Tarsitano MG, Franceschi F, Merra G. The role of IL-6 gene polymorphisms in the risk of lipedema. Eur Rev Med Pharmacol Sci. 2020 Mar;24(6):3236–3244. doi: 10.26355/eurrev_202003_20690. PMID: 32271442. | |
De Lorenzo A, Soldati L, Sarlo F, Calvani M, Di Lorenzo N, Di Renzo L. New obesity classification criteria as a tool for bariatric surgery indication. World J Gastroenterol. 2016 Jan 14;22(2):681–703. doi: 10.3748/wjg.v22.i2.681. PMID: 26811617; PMCID: PMC4716069. | |
Gualtieri P, Frank G, Cianci R, Dominici F, Mappa I, Rizzo G, De Santis GL, Bigioni G, Di Renzo L. Fish consumption and DHA supplementation during pregnancy: study of gestational and neonatal outcomes. Nutrients. 2024 Sep 10;16(18):3051. doi: 10.3390/nu16183051. PMID: 39339651; PMCID: PMC11434981. | |
Di Renzo L, Gualtieri P, De Lorenzo A. Diet, nutrition and chronic degenerative diseases. Nutrients. 2021 Apr 20;13(4):1372. doi: 10.3390/nu13041372. PMID: 33923865; PMCID: PMC8072879. | |
Larciprete G, Valensise H, Vasapollo B, Altomare F, Sorge R, Casalino B, De Lorenzo A, Arduini D. Body composition during normal pregnancy: reference ranges. Acta Diabetol. 2003 Oct;40 Suppl 1:S225–32. doi: 10.1007/s00592–003–0072–4. PMID: 14618479. | |
Zeng Z, Liu F, Li S. Metabolic adaptations in pregnancy: A Review. Ann Nutr Metab. 2017;70(1):59–65. doi: 10.1159/000459633. Epub 2017 Mar 16. PMID: 28297696. | |
Lain KY, Catalano PM. Metabolic changes in pregnancy. Clin Obstet Gynecol. 2007 Dec;50(4):938–48. doi: 10.1097/GRF.0b013e31815a5494. PMID: 17982337. | |
King JC. Physiology of pregnancy and nutrient metabolism. Am J Clin Nutr. 2000 May;71(5 Suppl):1218S–25S. doi: 10.1093/ajcn/71.5.1218s. PMID: 10799394. |
Online Study Assessment Option
All readers who are qualified doctors or allied medical professionals can automatically receive 1.5 Continuing Professional Development points plus a Study Completion Certificate from GLOWM for successfully answering four multiple-choice questions (randomly selected) based on the study of this chapter. Medical students can receive the Study Completion Certificate only.
(To find out more about the Continuing Professional Development awards program CLICK HERE)
