Metabolism involves the breaking down (destruction) of molecules to produce smaller molecules and Energy (catabolism), together with the utilization of this Energy to construct the molecules (especially Proteins and Nucleic Acids) required for the body's Growth and repair (anabolism).

After ingestion into the body via the Digestive System and Respiratory System, various nutrients are broken down into various molecules for input to the Krebs Cycle. The Krebs Cycle then removes Hydrogen atoms from molecules for delivery to the Electron Transport System - during this process the majority of the Adenosine Triphosphate that is used within the Mitochondria of the body's Cells as a source of Energy is produced. The Electron Transport System (ETS) accepts Hydrogen atoms from the Krebs Cycle and passes them through a series of compounds (combustion) until they combine with Oxygen to form Water - each cycle of this process produces 11 molecules of Adenosine Triphosphate (ATP). The Kidneys continually monitor the quality of the Blood so that the body is not poisoned by the end-products of its Metabolism.

In effect, metabolism is the amount of energy, or calories, that our body burns in order to function. Our bodies get energy, or calories, from the food we eat and metabolism is the chemical reaction in the body that converts this food into the fuel needed to do everything from thinking to running.

The speed at which our body burns these calories is called the metabolic rate.

Basal Metabolism involves the combustion of Food, using Oxygen and producing Carbon Dioxide - the rate of Oxygen consumption of an individual indicates their Energy expenditure, i.e. their Basal Metabolic Rate. The Basal Metabolic Rate measures the speed of all chemical reactions which occur when the body is lying completely at rest (preferably measured immediately upon wakening); for the activity of the internal organs and to maintain body temperature. Under normal conditions, Basal Metabolism varies between individuals of the same sex by not more than 5% (the BMR of females is on average 11% lower than that of males).

Increasing the Basal Metabolic Rate may alleviate Obesity (by accelerating the oxidation of Calories). When the body’s Basal Metabolic Rate increases, thermogenesis increases in tandem.

Increases in the body's Basal Metabolic Rate are mediated by the Adrenergic Nervous System.

Foods/Herbs That May Increase BMR:

• coffee
• astragalus
• chillis
• ephedra
• rosehips
• coconut oil
• mustard seeds

Other Substances that May Increase BMR:

• exposure to sunlight
• Human Growth Hormone
• Dopamine
• Testosterone
• Phosphorus
• Zinc
• Increased intake of water

Factors That Increase BMR:

• the process of digestion

The ingestion of calories in the form of Protein increases the body’s Metabolic Rate by up to 30% for as long as 12 hours after eating. Unlike calories derived from other sources, calories derived from Dietary Fats require very little endogenous Energy to be expended in digesting and metabolizing them, therefore ingestion of Dietary Fats do not increase the body’s BMR to the same extent that calories derived from other sources do.

• The colder the atmospheric Temperature, the more Energy the body must produce in order to keep it's internal Temperature constant

The BMR of people in colder climates is 10% greater than those living in the tropics.

• exercise temporarily increase BMR for up to 15 hours after exercise
• the greater a person's muscle mass, the greater the energy requirement
• the larger a person's surface area, the greater the energy requirement

Factors That Lower BMR:

• body's BMR may decline after the age of 30 because of the ageing process
• low-calorie diets

It is noteworthy that people on Low-Calorie Diets who concurrently perform regular Exercise do not experience the reduction in Basal Metabolic Rate normally experience by people on Low-Calorie Diets who do not engage in regular Exercise.

• diet restriction
• fasting
• hypothyroidism
• obesity
• BMR may slow down during sleep