Leptin is the hormone that is released in your body to tell you that you are full, and don't need to eat anymore. However, in obese people, leptin can be be overridden by the pleasure center in the brain, and this condition is called leptin resistance. Most obese people have high levels of leptin in their systems, but this is overridden by the pleasure center in the brain, and they don't feel full. Now a study in the British Journal of Nutrition shows that a high fat, high sugar diet directly leads to leptin resistance. The authors even use the word "cause" to describe this relationship. Further, when a high fat, no sugar diet is introduced, within three days, leptin resistance was reversed. They identify high fructose corn syrup as a major contributor to leptin resistance.
Another study found that routine, periodic fasting is good for your heart and your health. Conducted by Intermountain Health Care and funded by the "Deseret Foundation," you know there are Mormons at the heart of this study, scientifically legitimizing the monthly fast. Still, I find it interesting. Since being diagnosed as a diabetic in 2002, I have had an extremely hard time with the monthly fast, giving it up altogether some time around 2003. I felt shaky, weak, and generally awful during the fast. I chalked this feeling up to being diabetic, but looking back on it now, I realize it was because I was "starving" at the cellular level, since most of my carbohydrate intake was being stored as fat and not used as fuel. Adding fasting on top of cellular starvation was extremely unpleasant. Last month, however, I decided to try to fast again, and it was surprisingly easy, especially compared to how lousy fasting made me feel until I switched to a low carb regime. Fast Sunday is again this coming Sunday and I am actively looking forward to the opportunity to fast again.
The paleo nutrition web sites are all about something they call "intermittent fasting," since this is what our hunter/gatherer ancestors had to do on a regular basis, when they couldn't kill food. Some suggest they didn't eat all that regularly, and when they killed something, they gorged on it, but may have eaten two days out of three, and perhaps only once or twice a day on the days they did eat. Hence, the interest in intermittent fasting.
All of these insights in this post today come from the remarkable Michael R. Eades, M.D., whose blog and twitter page are amazing sources of information.