Art and Science of Hunger

Knut Hamsun  wrote  Hunger in 1890(1).  This Norwegian novel, set in Kristiania( modern day Oslo) , recounts the wretchedness of an aspiring  writer caught in the clutches of hunger. His unsolicited  essays are more often than not rejected    by  the publishers, and even on the rare occasions when accepted the reward is just  enough to cover food for a couple of days.   Poverty forces him to pawn every possible material possession he owns.  Partly autobiographical, the tortuous feeling of  hunger,  what it can do to  the physical and mental state of a human being, is splashed across the pages in vivid shades. His mind is at once delirious and sober, indulging  in snobbish fantasies  while still being acutely aware of the stark reality around.  Traumatized by hunger he even takes to chewing bark.   Thirty years later Kafka sketched the  " Hunger Artist"(2)  For Kafka's protagonist abstaining from food is an art and  he does it willingly out of no compulsion whatsoever. Proud of his skill, he is ever ready to demonstrate it under the watchful eyes of the  public ,   seeks no reward and ultimately  fades into oblivion.

Experts say that  one’s daily energy need could be as low as 1600kcals or as high  as 6000 kcals depending upon how heavily one sweats it out. (3) Coupled activity of two key hormones, at the hypothalamus,  ghrelin at the opening ceremony and leptin  during the closing ceremony,   orchestrates our feeding pattern(4). In other words, ghrelin is the start signal and leptin is the stop signal.   It indeed isn’t surprising at all that intense research in the area of obesity  has been instrumental in unraveling the intricate biochemical and neural pathways of hunger. Friedman (5)   and his colleagues at the Rockefeller Institute were doing precisely the same in obese mice population,   when they confronted  leptin  It is astounding that the amount of  leptin generated is proportional to the fat stored in the adipose tissue. That means there is a dynamic inventory going on.

Mutations in the leptin gene or lesions in the hypothalamus regions where leptin is supposed to exert its influence could lead to hyperphagia, a state where the body is in perpetually hungry mode leading  to overeating and obesity. Ghrelin the hunger hormone too acts at the hypothalamus, specifically  on a set of neurons called Agrp neurons.  If the AGRP neurons are provoked into frenzied activity   then again  hyperphagia develops. However,  if somehow  AGRP neurons can be sedated, then  the result is aphagia, loss of appetite and abstention from food.  August 9^th issue of Nature carries a research paper by   Sternson and his team at the Janelia Farm Research Campus, Howard Hughes Medical Institute, Virginia, (USA), which tries to map the   neural circuitry of hunger.(6)  Their findings,  team hopes would prove helpful in  overeating disorders.

At the  Museo Nacional Centro de Arte Reina Sofia, Madrid  

1. Hunger by Knut Hamsun

2. Hunger  Artist  in Selected Short Stories of Franz Kafka, Srishti Publishers, New Delhi 

3. Biochemistry of Hunger 

4.  The role of leptin and ghrelin in the regulation of food intake and body weight in humans: a review Klok  Jakobsdottir  Drent ,  Obes Rev. 2007 Jan;8(1):21-34.

5. JeffreyFriedman 
6.The Deconstruction of a neural circuit for hunger : Atasoy, Betley and Sternson, Nature vol. 488, 9^th August, 2012, pages 172-177