Anything to back them up? Are you fucking kidding me? He's quoting New Age Tai Chi bullshit. You want to know his source? Here it is word for word: http://www.chuckrowtaichi.com/HungerPangs.html You want to actually learn? Get fucking reading:
https://ocw.mit.edu/courses/biology/7-01sc-fundamentals-of-biology-fall-2011/
https://ocw.mit.edu/courses/brain-and-cognitive-sciences/9-00sc-introduction-to-psychology-fall-2011/
https://www.amazon.com/Human-Anatomy-Physiology-Elaine-Marieb/dp/0321927044/
https://www.amazon.com/Principles-Animal-Behavior-Third-Dugatkin/dp/0393920453
https://www.amazon.com/Motivation-Psychological-Environmental-Lambert-Deckers/dp/0205941001

Part 2:

Anatomy and Physiology

• Gray's Anatomy. My friend suggests getting both a modern version and if you can, one of the classical editions. She does not like the Barnes and Noble or some of the other "collector editions" because she thinks the illustrations are too small to read, despite the elegant binding they come in.
  
  
• The Anatomy Coloring Book My friend greatly recommends the entirety of this series of books.
  
  
• Human Anatomy and Physiology by John W. Hole. My friend owns the 2nd edition (1981) version of this book. She can't speak for the newer, modern version but she says this is an excellent college-level text on human anatomy and physiology.
  
  
• Human Anatomy & Physiology (Marieb, Human Anatomy & Physiology). This is a more modern text that my friend has and suggests.
  
  

  Other Medical Texts (Pathology, organic chemistry, biology, nutritional science, etc)
  

  
  

• Clinical Pathophysiology Made Ridiculously Simple by Aaron Berkowitz
  
  
• Robbin's Basic Pathology
  
  
• Food and Western Disease: Health and Nutrition From An Evolutionary Perspective
  
  
• Advanced Nutrition and Human Metabolism
  
  
• Whole: Rethinking the Science of Nutrition
  
  
• Real Food For Pregnancy by Lily Nichols
  
  
• Nutritional Grail: Ancestral Wisdom, Breakthrough Science, and the Dawning Nutritional Renaissance
  
  
  
• Dr. Klein's Organic Chemistry (textbook)
  
  
• Campbell's Biology (textbook) - Any newer edition will do. She also suggests the biology coloring book as an additional exercise book.
  
  

  Formularies, Pharmacy
  

  
  

• Herbal Formularies for Health Professionals, Volume I, Volume II, and Volume III by Dr. Jill Stansbury
  
  
• Fenner's Formulary: Containing Formulae for the Preparation of All the Elixirs, Emulsions, Essences, Flavoring Extracts, Glycerites, Solutions, ... Preparations, Now in Use by Byron Fenner. A classical formulary, it is also available in PDF form from forgottenbooks and the SWSBM.
  
  
• Remington: The Practice and Science of Pharmacy
  
  
  

  Classical Herbals
  

  
  
  

• Culpeper's Herbal
  
  
• King's American Dispensatory
  
  
• The classical herbals listed on Henriette's Herbal Page