My good friend and health geek Steven Bentley called me to share some awesome research he’d found that would enhance the way I had cleansed for the last 10 years. From the link below I learned some cool facts that will help you gain better health.
Glucose and fat are the body’s main sources of energy. If glucose is not available, then the body will adjust by using fat, without any detrimental health effects. This is simply a natural part of life. Periods of low food availability have always been a part of human history. Mechanisms have evolved to adapt to this fact of Paleolithic life. The transition from the fed state to the fasted state occurs in several stages.
- Feeding – During meals, insulin levels are raised. This allows uptake of glucose into tissues such as the muscle or brain to be used directly for energy. Excess glucose is stored as glycogen in the liver.
- The post-absorptive phase – 6-24 hours after beginning fasting. Insulin levels start to fall. Breakdown of glycogen releases glucose for energy. Glycogen stores last for roughly 24 hours.
- Gluconeogenesis – 24 hours to 2 days – The liver manufactures new glucose from amino acids in a process called “gluconeogenesis”. Literally, this is translated as “making new glucose”. In non-diabetic persons, glucose levels fall but stay within the normal range.
- Ketosis – 2-3 days after beginning fasting – The low levels of insulin reached during fasting stimulate lipolysis, the breakdown of fat for energy. The storage form of fat, known as triglycerides, is broken into the glycerol backbone and three fatty acid chains. Glycerol is used for gluconeogenesis. Fatty acids may be used for directly for energy by many tissues in the body, but not the brain. Ketone bodies, capable of crossing the blood-brain barrier, are produced from fatty acids for use by the brain. After four days of fasting, approximately 75% of the energy used by the brain is provided by ketones. The two major types of ketones produced are beta hydroxybutyrate and acetoacetate, which can increase over 70 fold during fasting.
- Protein conservation phase – >5 days – High levels of growth hormone maintain muscle mass and lean tissues. The energy for maintenance of basal metabolism is almost entirely met by the use of free fatty acids and ketones. Increased norepinephrine (adrenalin) levels prevent the decrease in metabolic rate.
The human body has well developed mechanisms for dealing with periods of low food availability. In essence, what we are describing here is the process of switching from burning glucose (short term) to burning fat (long term). Fat is simply the body’s stored food energy. In times of low food availability, stored food is naturally released to fill the void. So no, the body does not ‘burn muscle’ in an effort to feed itself until all the fat stores are used.
- Lowers insulin levels and has also been shown to improve insulin sensitivity significantly.
- One of the most potent stimuli to growth hormone secretion is fasting.
- Adrenalin levels are increased so that we have plenty of energy to go get more food. For example, 48 hours of fasting produces a3.6% increase in metabolic rate, not the dreaded metabolic ‘shut-down’.
- Increases lean muscle mass.
- Burns fat and helps lose weight safely