What Is Intermittent Fasting?
It has been known for decades that a calorie restricted diet without malnutrition increases longevity by a significant amount.
However intermittent fasting consists of alternate day fasting, or energy restriction. The current research uses various dietary protocols, from 4-day 50-calorie fasts, to fasting 24-48 hours while drinking only water and green tea, to alternate-day fasting where you eat a healthy, nutritious meal of 400-600 calories (green leafy vegetables, lean meats, nuts and fruit) followed by a feed day, where you eat anything you want. All these methods have similar results.
If intermitted fasting is done properly you don’t even have to have a great feed day. I have researched this subject extensively and it has shown without a shadow of a doubt that calorie restriction has amazing effects on the body, of course done in a structured way.
In 2009, a 20-year longitudinal study of adult-onset calorie restriction in rhesus monkeys demonstrated that moderate calorie restriction lowered the incidence of aging-related deaths. At the time of reporting, 50% of control animals survived, compared with 80% of calorie restricted animals. Calorie restriction delayed the onset of several age associated pathologies such as diabetes, cancer, cardiovascular disease and brain atrophy. The calorie restriction trial in primates raised hope that calorie restriction might be effective in humans.
Nevertheless, intermittent fasting resulted in beneficial effects that met or exceeded those of caloric restriction including reduced serum glucose and insulin levels and increased resistance of neurons in the brain to excitotoxic stress. Intermittent fasting therefore has beneficial effects on glucose regulation and neuronal resistance to injury.
We have been told to eat many small meals a day and that if we don't eat we will lose muscle mass, we will trigger the starvation reflex and put on more weight. The research, which is already over 10 years old, is showing something remarkable different.
Matterson from John Hopkins university et al have reported that fasting is a challenge to the brain, and the brain responds to that challenge by adapting stress response pathways which help the brain cope with stress and risk for disease. The same changes that occur in the brain during fasting mimic the changes that occur with regular exercise. They both increase the production of protein in the brain (neurotrophic factors), which in turn promotes the growth of neurons, the connection between neurons, and the strength of synapses.
Neuroscientists found that cycles of prolonged fasting not only protect against immune system damage — a major side effect of chemotherapy — but also induce immune system regeneration, shifting stem cells from a dormant state to a state of self-renewal.
In both mice and a Phase 1 human clinical trial involving patients receiving chemotherapy, long periods of not eating significantly lowered white blood cell counts. In mice, fasting cycles then “flipped a regenerative switch,” changing the signaling pathways for hematopoietic stem cells, which are responsible for the generation of blood and immune systems.
Look at this video where Dr. Joseph Marcela talks about intermittent fasting. He has a great article that gives even more detail.