Posts Tagged ‘Macronutrients’

What the heck is a snack anyways? How many calories is it outside today?.

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Pancreas…Insulin…Body Fat! Ohh My!!.

The Forbidden (timing of) Fruit!.

Human Energy Systems & Metabolism.

Macronutrient Energy Systems…

Energy can be derived from three major food sources, commonly referred to as Macronutrients- Proteins, Carbohydrates, and Fats (lipids). Energy can also be derived from Alcohol…as well as, increased estrogen levels in men coupled with elevated aromatization, specifically at androgen receptor sites, sclerosis of the liver, crazy fluctuation of Insulin levels, not to mention a cascade of catabolic processes that are set in motion. Generally (minus a couple rare extenuating circumstances), one gram of each of the three nutrients (plus Alcohol) yield the following calories:

1 gram of Protein = 4 calories
1 gram of Carbohydrates = 4 calories
1 gram of Fat = 9 calories
1 gram of Alcohol = 7 calories

For all intents and purposes, the calories in food represent a form of potential energy for our bodies to produce heat and to work. Knowing how many calories (i.e. energy) are in the foods consumed can reveal how much we need to perform the work inside our bodies as well as all our movements (e.g., Gain Weight). Conversely, if we eat less than we need, the body will draw on it’s stores for energy (i.e., lose fat/weight).

Human Energy Systems…

Our bodies must take the energy stored in foods (macronutrients) and transform it into an energy form our cells can use immediately and/or store for future use. Energy in the body is available for immediate use in the form of Adenosine Triphosphate (ATP). It is a complex molecule constructed with high-energy bonds which, when split by enzyme action, releases energy rapidly for a number of body processes including tissues in small amounts. Another related high-energy phosphate compound, phosphocreatine (CP), is also found in the tissues in small amounts. Although it cannot be used as an immediate source of energy, it can rapidly replenish ATP. ATP can be formed from protein, carbs, and fats.
Metabolism; Human metabolism represents all physical and chemical changes that take place in the body. Metabolism involves two fundamental processes: Anabolism and Catabolism. Anabolism is a building-up or constructive metabolism. Catabolism is the tearing-down process involving the disintegration of body compounds into their simpler components. The breakdown of muscle glycogen to glucose and eventually CO2, H20 and energy
is an example of a catabolic process. The energy released from some catabolic processes is used to support the energy of anabolism. Therefore, metabolism represents human energy. The metabolic rate reflects how rapidly the body uses it’s energy (calories) stores. Many factors affect this rate but none so much as lean body mass (LBM) and exercises.

Basal metabolism or Basal Metabolic Rate (BMR) represents the energy (calories) required for fundamental life functions at rest, not including digestion of food. Resting Metabolic Rate (RMR) is the BMR plus the additional energy expenditure needed to digest food. RMR is typically 5-10% higher than BMR. If we can estimate our RMR and add our daily activity energy needs, we arrive at an estimate of our daily total energy (calorie) requirements. This is our caloric maintenance level. In other words, our body fat or weight remains stable when consuming this amount of food. A favorable or unfavorable body composition change results from a disruption in a caloric maintenance or energy balance.