When subjects are asked to watch a movie and not display emotions (say, a comedy without laughing, or a tearjerker without crying), they evidently use up glucose in particular areas of their brain in a way that subjects who are free to react however they want do not.
This leads to increased activity in the nucleus accumbens and the amygdala, and as a result of this activity, a craving for sweets.
Moreover, after the subjects receive sugary drinks, the increased activity in the nucleus accumbens and the amygdalaose settles down. This is just one of a great many experiments that show that controlling one's emotions takes will power and that the exercise of will power uses up glucose.
When we're sick, our bodies use energy to fight off diseases. And when we're sleep deprived, we evidently do not process the glucose in our blood stream as well. All of which explains why the phrase "sick and tired of..." is often uttered by someone no longer able to control his emotions.
During the luteal phase of the menstrual cycle, the premenstrual phase, the female body shuttles energy to the ovaries and into the production of hormones. With their glucose diverted to such purposes, women suffer mood swings because they lack the glucose necessary to control their emotions. And they crave sweets, eating on average 170 more calories at lunch than usual.
So, the next time you're walking on egg shells because it's that time of the month, offer your wife a candy bar.
- Willpower, 2011 book by Roy Baumeister & John Tierney, page 50-60
- "Correlates of Self-regulatory Depletion in Chronic Dieters" by K Demons, C. Amble, D. Wagner, W. Kelley, & T. Heatherton, 2011 poster session at the Society for Personality and Social Psychology
- "That Time of the Month Again" 2009 article by Jennifer Love Hewitt, OK! September 22, 2009
- "It Ruins a Large Portion of my Life": "The Worst PMS on the Planet", NoPeriod.com
- "A Theory of Limited Metabolic Energy and Premenstrual Syndrome (PMS) Symptoms: Increased Metabolic Demands During the Luteal Phase Divert Metabolic Resources from and Impaired Self-Control," 2010 article by M.T. Gailliot, B. Hildebrandt, L.A. Eckel, & R.F. Baumeister, in Review of General Psychology 14 (2010) 269-82