During development while in the womb, there are specific periods in which organs and other bodily systems are developing. These critical periods of development can be affected by exposures to toxic stress, poor nutrition, or environmental pollutants. The length and timing of these stressors on the developing baby affect how the organ will develop and ultimately the long term chronic disease risk
“Trading-off” is a process that initially seems beneficial as the developing baby can restrict or allow development based upon the its environment, with the end goal of survival. These trade-offs however do not always match the true environment the developing baby will experience after birth, and the periods of limited development lead to greater risk of chronic disease in adulthood. For example, a fetus that is not able to get enough nutrients has the ability to limit its growth by developing insulin resistance in order to survive birth. Being insulin resistant becomes a problem if the post-birth environment of the child is nutrient rich then the child can possibly have type 2 diabetes.
Armitage, J. A., Taylor, P. D., & Poston, L. (2005). Experimental models of developmental programming: Consequences of exposure to an energy rich diet during development. The Journal of Physiology,565(1), 3-8.