I have observed that frequently when people are hungry; they tend to get angry more easily on pointless issues. Does this mean that our fight or flight response is more active when a person is hungry? What is a possible reason for this? Is this phenomenon linked with our cell signaling pathways? If it is, then what would be the pathway that leads to the aggressive behavior?

To summarize the question:

When a person is hungry and they get angry, is it due to a cell signaling pathway? If so, what pathway?

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    $\begingroup$ As I recall hypoglycaemia leads to a sympathetic response that can promote fight/flight behaviour. $\endgroup$
    – Rory M
    Jul 6, 2014 at 15:44
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    $\begingroup$ I think a review should be offered to this post biology.stackexchange.com/questions/19515/… to answer this enough well. Testosterone in relation of hunger and aggressive behavior is a valid research topic. $\endgroup$ Jul 8, 2014 at 14:42
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    $\begingroup$ Could you please tell me what u r missing in the answer that Cornelius has given for you have put up a bounty on this question? $\endgroup$ Jul 9, 2014 at 4:22
  • $\begingroup$ I would say simply that when we are hungry, we feel a certain degree of pain and diminished emotional security. this puts us on the defensive and makes it harder for us to bear difficulty, so we snap out at those things (or people) which make our lives harder. $\endgroup$
    – user813801
    Jul 9, 2014 at 5:53
  • $\begingroup$ @TheLastWord from the answer,I got it that hypoglycemic condition leads to the Release of Epinephrine and nor epinephrine and activation of beta adrenergic receptors, but how the activation of this signalling pathway leads to aggressive behavior? Is their release of any hormone or secondary messenger in this pathway that effects behavior..?? wondering about this, can you explain me this point..please..??? $\endgroup$ Jul 9, 2014 at 12:32

2 Answers 2


Brain's main energy source is glucose. It uses about 20% of total glucose [1]. Brain hypoglycemia causes depressive-like behaviors in mice through adrenergic pathways [2].

When it comes to humans, here is a study that claims low glucose leads to increased aggression in married couples (see this too):

Self-control requires energy, part of which is provided by glucose. For 21 days, glucose levels were measured in 107 married couples. To measure aggressive impulses, each evening participants stuck between 0 and 51 pins into a voodoo doll that represented their spouse, depending how angry they were with their spouse. ... As expected, the lower the level of glucose in the blood, the greater number of pins participants stuck into the voodoo doll, and the higher intensity and longer duration of noise participants set for their spouse [3].

However, the conclusion is disputed:

Bushman et al.'s study does not demonstrate that fluctuations in blood glucose affect individuals' self-control abilities. As an important consequence, there is no reason to assume that giving couples a sugary “boost to their self-control energy” (p. 3) will reduce intimate partner violence. Because the glucose model of self-control lacks empirical foundation, it does not qualify as a framework for scientifically based intervention strategies [4].

What is sure, is that hypoglycemia activates sympathetic nervous system:

... the neurogenic symptoms of hypoglycemia are largely the result of sympathetic neural, rather than adrenomedullary, activation [5].

Hypoglycemia increases plasma levels of both epinephrine and norepinephrine. These catechols are released primarily from the adrenal medulla. However, it is well documented that hypoglycemic increases muscle sympathetic nerve activity, and that both alpha and beta adrenergic activity increase [6].

And this leads to behavioral changes (at least in animals):

Noradrenaline is involved in many different functions, which all are known to affect behaviour profoundly. ... Part of these effects may arise in indirect ways that are by no means specific to aggressive behaviour, however, they are functionally relevant to it. Other effects may affect brain mechanisms specifically involved in aggression. Hormonal catecholamines (adrenaline and noradrenaline) appear to be involved in metabolic preparations for the prospective fight; the sympathetic system ensures appropriate cardiovascular reaction, while the CNS noradrenergic system prepares the animal for the prospective fight. ... It appears that neurons bearing postsynaptic alpha2-adrenoceptors are responsible for the start and maintenance of aggression, while a situation-dependent fine-tuning is realised through neurons equipped with beta-adrenoceptors [7].


  1. Wikipedia contributors, "Human brain," Wikipedia, The Free Encyclopedia, http://en.wikipedia.org/w/index.php?title=Human_brain&oldid=615456836 (accessed July 6, 2014).
  2. Park MJ, Yoo SW, Choe BS, Dantzer R, Freund GG. Acute hypoglycemia causes depressive-like behaviors in mice. Metab. Clin. Exp. 2012 Feb;61(2):229-36. doi: 10.1016/j.metabol.2011.06.013. PubMed PMID: 21820138.
  3. Bushman BJ, Dewall CN, Pond RS, Hanus MD. Low glucose relates to greater aggression in married couples. Proc. Natl. Acad. Sci. U.S.A. 2014 Apr 29;111(17):6254-7. doi: 10.1073/pnas.1400619111. PubMed PMID: 24733932.
  4. Lange F and Kurzban R (2014) Sugar levels relate to aggression in couples without supporting the glucose model of self-control. Front. Psychol. 5:572. doi: 10.3389/fpsyg.2014.00572
  5. DeRosa MA, Cryer PE. Hypoglycemia and the sympathoadrenal system: neurogenic symptoms are largely the result of sympathetic neural, rather than adrenomedullary, activation. Am. J. Physiol. Endocrinol. Metab. 2004 Jul;287(1):E32-41. doi: 10.1152/ajpendo.00539.2003. PubMed PMID: 14970007.
  6. Hoffman RP. Sympathetic mechanisms of hypoglycemic counterregulation. Curr Diabetes Rev. 2007 Aug;3(3):185-93. PubMed PMID: 18220670.
  7. Haller J, Makara GB, Kruk MR. Catecholaminergic involvement in the control of aggression: hormones, the peripheral sympathetic, and central noradrenergic systems. Neurosci Biobehav Rev. 1998;22(1):85-97. PubMed PMID: 9491941.
  • $\begingroup$ Ok... I got it that hypoglycemic condition leads to the Release of Epinephrine and nor epinephrine and activation of beta adrenergic receptors, but how the activation of this signalling pathway leads to aggressive behavior? Is their release of any hormone in this pathway that effects behavior..?? wondering about this, can you explain me this point please..??? $\endgroup$ Jul 7, 2014 at 13:12
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    $\begingroup$ @katherinebridges Those hormones activate sympaticus (fight-flight-response) - increased blood pressure, irritation, uneasiness when prolonged. Different people react to it differently (different genomics). Some become very aggressive, some are just silent and calm. Probably, testosterone and male gender have something to do with this. Men need more energy than female every day so they are exhausted faster. Link between hunger and testosterone can be one thing. $\endgroup$ Jul 8, 2014 at 14:21
  • $\begingroup$ @Masi can you give me any reference for the involvement of testosterone hormone in developing aggressive behavior due to hunger..?? $\endgroup$ Jul 9, 2014 at 12:38
  • $\begingroup$ @Masi you have asked me to provide the reference for the link between testosterone hormone in developing aggressive behavior due to hunger..? $\endgroup$ Jul 11, 2014 at 14:17
  • $\begingroup$ @katherinebridges I am working on this now. It will take some time because I have to study again some of the genetics and embryology related to this one. I try to find something until Saturday. $\endgroup$ Jul 11, 2014 at 17:42

This is a short review about the issue and not complete. This and the earlier answer are not proofs of the link between the two proceses.

To investigate this better, I think it would be much easier first to narrow the case to

  • testosterone and energy homeostasis (Embryology; or better formulated research case)
  • catabolism and anger
  • anger and aggressive behaviour.

Then, think about specific cases. Think genes which are associated with aggressive behaviour and violence in catabolism (criminal studies).


  • Satiety
  • Appetite
  • Hunger

I was not sure in which specific area you are particularly interested. At this stage, we cannot provide a proof between hunger and aggressive behaviour. It depends so much on the individual (life style; genomics) what is the end result. Here follows little general pieces of information:

Some cases

  • InsR/FoxO1 Signaling Curtails Hypothalamic POMC Neuron Number [1]: it's possible that the hormonal and nutrient milieu contributes to alterations in POMC neuron development.
  • Early-Life Exposure to Testosterone Programs the Hypothalamic Melanocortin System [3].
  • Study about testosterone and basal metabolic rate [2].


  • hypothalamus lateral nucleus
  • hypothalamus tuberal medial perifornical nucleus [4]
  • hypothalamus arcuate nucleus (appetite and energy expenditure - POMC-CART; upregulative NPY AGRP)


  • androgenic (NR3C4) (adipose tissue; more in visceral) (no link)

where I found no receptor existing directly between those two events - appetite and testosterone secretion by comparing the NCBI gene databases between those two processes. It is much more easier to show the thing first in the embryologic studies and then by using the gene found in bigger studies. At the moment, more work is needed in these studies in Embryology.

My initial clause is based on some of my notes in Embryology. There are researches who are trying to show this link between studies in embryology. The problem is at the moment in the development of hypothalamus and something else. I will update this post when I remember about the situation better and when finding the right things from my notes.


  1. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3271107/#!po=14.0625
  2. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3402517/
  3. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3060636/
  4. John E. Hall. Guyton and Hall Textbook of Medical Physiology. 12Th edition.

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