3.Ghrelin

CATEGORY:

•Hormone

DEFINITION:

•Insatiable Hormone

•Peptide Hormone produced in Gastrointestinal Tract

FUNCTION:

•A neuropeptide in CNS that regulates hunger...increases appetite as levels rise

•Plays significant role in distribution and rate of use of energy

ACTION:

•When stomach is empty Ghrelin is released to initiate hunger

•Ghrelin released when Leptin levels fall

FACTS:

•Plays role in regulating reward perception in Dopamine Neurons...linked with sexual desire and reinforcement/development of addictions

•Elevated levels of Ghrelin can lead to weight gain even if consumption is curbed

MANIPULATION:

•Adequate sleep reduces Ghrelin

DIETING:

•Stimulates release of Growth Hormone from the pituitary gland, which breaks down fat tissue and causes the build-up of muscle

•Carbohydrates and Proteins restrict the production and release of Ghrelin to a greater extent than Fats

•Levels increase after dieting, leading to weight gain

•Consuming Fibre can reduce the affects of Ghrelin due to the released affects of CCK on satiety

RELATED TO:

•Leptins

NOTES:

•What is link to Prefrontal Cortex...addictions & habits????

•Stimulates release of Growth Hormone...when & how???

•Since Protein inhibits it then having Protein for breakfast inhibits release of HGH and is an argument for fasting (which has added desirable affect of releasing Testosterone)...but not an argument against it being first meal of day on daily basis!!!