University of Hawai‘i at Mānoa Food Science and Human Nutrition Program and Human Nutrition Program
I maika‘i ke kalo i ka ‘ohā
The goodness of the taro is judged by the young plant it produces
By the end of this chapter you will be able to:
- Describe the physiological basis for nutrient requirements from pregnancy through the toddler years.
The Human Life Cycle
Human bodies change significantly over time, and food is the fuel for those changes. For example, for Native Hawaiians, expecting mothers were encouraged to eat greens like the lu‘au (young taro leaves) and palula (young sweet potato leaves) to encourage a healthy, strong baby. These beliefs and customs practiced in the early stages of life were done in hopes of building a firm foundation and setting up lifelong health.
People of all ages need the same basic nutrients—, carbohydrates, essential fatty acids, and twenty-eight vitamins and minerals—to sustain life and health. However, the amounts of nutrients needed differ. Throughout the human life cycle, the body constantly changes and goes through different periods known as stages. This chapter will focus on pregnancy, and the toddler years. Chapter 14 will focus on childhood through adolescence and Chapter 15 will focus on the stages of adulthood. The major stages of the human life cycle are defined as follows:
- Pregnancy. The development of a into an and then into a in preparation for childbirth.
- Infancy. The earliest part of childhood. It is the period from birth through the first birthday.
- Toddler years. Occur during ages one to three and are the end of early childhood.
- Childhood. The period from birth to eighteen.
- Onset of . Can occur from ages nine to fourteen, which is the beginning of adolescence.
- Older adolescence. The stage that takes place between ages fourteen and eighteen.
- Adulthood. The period from the end of adolescence to the end of life and begins at age eighteen in the US and nineteen in some other countries.
- Middle age. The period of adulthood that stretches from age forty-five to sixty-four.
- Senior years, or old age. Extend from age sixty-five until the end of life.
Figure 13.1 Ultrasound image of a four-month-old fetus.
We begin with pregnancy, a developmental marathon that lasts about forty weeks. It begins with the first (weeks one to week twelve), extends into the second trimester (weeks thirteen to week twenty-seven), and ends with the third trimester (week twenty-eight to birth). At conception, a sperm cell fertilizes an egg cell, creating a zygote. The zygote rapidly divides into multiple cells to become an embryo and implants itself in the uterine wall, where, by the end of the 8th week after conception, it develops into a fetus. Some of the major changes that occur include the branching of nerve cells to form primitive neural pathways at eight weeks. At the twenty-week mark, physicians typically perform an ultrasound to acquire information about the fetus and check for abnormalities. By this time, it is possible to know the sex of the baby. At twenty-eight weeks, the unborn baby begins to add body fat in preparation for life outside of the womb. The ability to coordinate sucking and swallowing, necessary for feeding at birth, is not present until 32-34 weeks, and matures around 36-38 weeks gestation.
Throughout this entire process, a pregnant woman’s nutritional choices affect not only fetal development, but also her own health and the future health of her newborn.
Technology Note: The second edition of the Human Nutrition Open Educational Resource (OER) textbook features interactive learning activities. These activities are available in the web-based textbook and not available in the downloadable versions (EPUB, Digital PDF, Print_PDF, or Open Document).
Learning activities may be used across various mobile devices, however, for the best user experience it is strongly recommended that users complete these activities using a desktop or laptop computer and in Google Chrome.
- Pukai MK., Handy ESC. (1958). The Polynesian Family System in Ka-‘u. Rutland, Vermont: Charles E. Tuttle Company ↵
- Polan EU, Taylor DR. (2003), Journey Across the LifeSpan: Human Development and Health Promotion. Philadelphia: F.A. Davis Company, 81–82. ↵
- Stanford Children’s Health. (n.d.). Retrieved June 9, 2020, from https://www.stanfordchildrens.org/en/topic/default?id=newborn-reflexes-90-P02630 ↵
An amino acid that cannot be synthesized by the body or synthesized in sufficient quantities to meet the body’s needs.
The period of early childhood from birth to 1 year of age.
Fertilized egg cell that results from the union of a female egg with a male sperm
The developing early stages of a human from two to eight weeks after conception.
The unborn developing human from the ninth week after conception to birth.
A period of sexual maturity where rapid growth and physical changes occur.
The term used to describe each 3 month period of a pregnancy.