Thrifty phenotype refers to the correlation between low birth weight of neonates and the increased risk of developing metabolic syndromes later in life, including type 2 diabetes and cardiovascular diseases.
[3] In their study, the authors reviewed the literature up to and addressed five central questions regarding role of different factors in type 2 diabetes on which they based their hypothesis.
These questions included the following: From the review of the existing literature, they posited that poor nutritional status in fetal and early neonatal stages could hamper the development and proper functioning of the pancreatic beta cells by impacting structural features of islet anatomy, which could consequently make the individual more susceptible to the development of type 2 diabetes in later life.
[10] The thrifty phenotype hypothesis says that early-life metabolic adaptations help in survival of the organism by selecting an appropriate trajectory of growth in response to environmental cues.
It has been suggested that the thrifty phenotype is the consequence of three unlike adaptive processes: maternal effects, niche construction and developmental plasticity, which all are influenced by the brain.
[13] An example of this phenomenon is a study published in 2018 by the Royal Society, which found that hypoxic stress from differing altitudes affected offspring limb length.
Individuals with a thrifty phenotype will have "a smaller body size, a lowered metabolic rate and a reduced level of behavioral activity… adaptations to an environment that is chronically short of food" (Bateson & Martin, 1999[16]).
Those with a thrifty phenotype who actually develop in an affluent environment may be more prone to metabolic disorders, such as obesity and type II diabetes, whereas those who have received a positive maternal forecast will be adapted to good conditions and therefore better able to cope with rich diets.
[20] On a larger anatomic scale, the molecular mechanisms are broadly caused by a suboptimal environment in the reproductive tract or maternal physiological adaptations to pregnancy.