Knowledge Tree
Type 1 allostatic overload
Also known as: Type II allostatic overload, allostatic overload Type 1
Facts (15)
Sources
Allostasis revisited: A perception, variation, and risk framework frontiersin.org Sep 28, 2022 11 facts
claimThe distinction between Type I and Type II allostatic overload is that Type I involves responding directly to physiological starvation (actual Potential Reproductive Potential = 0), whereas Type II involves responding to an alternative predictor of impending negative energy balance that may or may not accurately reflect low Potential Reproductive Potential.
referenceWada (2019) suggests that thresholds defined by damage, such as Type II allostatic and homeostatic overload, are difficult to pinpoint because damage accumulation and repair mechanisms are involved.
claimPerturbation resistance potential (PRP) reflects an individual's vulnerability to allostatic overload Type 1 if additional perturbations or resource limitations occur.
claimThe cost of surrendering a physical location includes losing fitness-related investments from the normal life-history stage and increasing the risk of damage from Type II/allostatic overload.
claimAllostatic overload Type 1 occurs when an animal is in a state of negative energy balance, which is considered an undisputed signal of a threat to Potential Reproductive Potential (PRP).
formulaAllostatic overload Type 1 occurs when an animal is in a negative energy balance, specifically when the sum of all types of allostatic load exceeds resource availability (Eg).
formulaPerturbation resistance potential (PRP) is a quantity in the framework of allostasis that describes the difference between allostatic load and resource availability, calculated as Eg – (Ee + Ei), and reflects an individual's vulnerability to allostatic overload Type 1.
claimAs climate change causes shifts in habitats globally, highly responsive individuals and groups may become more vulnerable to Type II allostatic overload.
claimType 1 allostatic overload may lead to homeostatic overload, but this is not always the case; if Emergency Life History Stage (ELHS) activation is short-lived and does not cause damage, it falls within the range of reactive homeostasis.
claimType II allostatic overload is most likely to occur in humans and captive animals because they live in environments where resource availability is disconnected from historically relevant cues.
claimType II allostatic overload is considered to be rare in wild animal populations.
Understanding Allostasis: Stability Through Change - Cannelevate cannelevate.com.au Jan 2, 2026 4 facts
claimType 1 allostatic overload is characterized by decreased thyroid hormone (T3) levels as the body conserves energy and can resolve once the perturbation passes and resources become available.
referenceMcEwen and Wingfield identified two distinct types of allostatic overload: Type 1, which occurs when energy demand exceeds available energy supply, and Type 2, which occurs with sufficient or excess energy consumption accompanied by social conflict or dysfunction.
claimType 1 allostatic overload occurs when energy demand exceeds available energy supply, activating an 'emergency life history stage' that triggers escape responses and emergency coping.
claimType 1 allostatic overload activates an 'emergency life history stage' characterized by a shift to survival mode, escape responses, and decreased thyroid hormone (T3) levels to conserve energy; it can resolve once the perturbation passes and resources become available.