The Body 's Energy From Four Key Fuels

The concept of energy intake and expenditure refers to the amount of calories per day that an individual consumes, and is the chemical energy in foods which can be metabolized to produce energy available to the body. As stated before energy is obtained from the foods we eat and is used to support an individual’s Basal Metabolic Rate, energy is measured in calories or joules as both units are very small they are multiplied by 1,000 and referred to as kilocalories. Different foods provide us with different amounts of energy, and the potential fuel sources available to exercising muscles are fats – 1 gram fat =9.0kcal = 23kJ,

According to Mark Sisson (2009), longer-term ketosis can result from fasting or staying on a low-carbohydrate diet, and ketosis that’s deliberately induced serves as a medical intervention for epilepsy. In glycolysis, higher levels of insulin block release of fat from adipose tissues and promote storage of body fat, while the body is in ketosis, fat reserves are continually released and consumed as energy (Sisson, 2009, p.47). This is why ketosis is referred to as

The heart is a major organ in the body, this organ pumps blood around the body, through veins, capillaries and arteries. The blood carries oxygen to our cells and also carries waste products which include water and carbon dioxide, which are products of respiration. Blood also helps spread out salts, enzymes, urea, nutrients, hormones and heat across the body.

The lack of calories consumed during fasting has dramatic effects on the body’s systems. Because of the

“Explain the physiology of two named body systems in relation to energy metabolism in your body”

In our bodies we need energy so that we could do things that are possible such as move our muscles, talk and all the other things that we do. Without energy all humans would be useless not being able to do anything. Energy is needed to extract the oxygen from the areas in our bodies and diffuse it into our bloodstream. Supplying enough energy to support the functions of the body in a daily basis is one of the main reasons for food. This energy comes from the fats, carbohydrates, and proteins in the food you eat. Of the three, fat is the most concentrated source of energy. Energy requirements are normally put in terms of calories. The energy requirement for a person is spilt into two parts: basal metabolic requirements and energy required for activity. Basal metabolic rate (BMR) is the heat taken from the body at rest when temperature is normal. An average person requires 2000-2500 Calories per day while the difference for a large man doing heavy work may require up to 6000 Calories per day. When you choose foods that have more energy, or Calories than you need, the excess energy is stored as fat in the body which will results in putting on some weight. If too little food is eaten to meet energy demands, the body's stored fat serves as an energy source and this will result in weight loss. Your weight stays about the same if the energy from food matches the energy requirements of the body. As warm blooded

When energy-yielding nutrients are consumed in excess, which one(s) can lead to storage of fat?

Insulin is a hormone that is produced from what is known as the “islets of Langerhans”, discovered by German Histologist Paul Langerhans, and is required for the utilization of glucose in muscle cells for energy. If the muscles are deprived of glucose for energy conversion, the muscles begin to utilize fat for energy (Roth). This however has toxic side effects, such as the production of high blood levels of Ketone bodies or otherwise known as Acetone. In high quantities, Acetone will accumulate in the blood, leading to brain damage and the possibility of brain death (Roth).

Ketones were high during fasting and low after eating because they were needed at first to generate ATP.

Ketosis is a metabolic state where the liver produces organic molecules known as ketone bodies. Technically, the term ketone denotes an organic molecule where a carbon atom, sandwiched between two other carbon atoms, is double-bonded to an oxygen atom (Peter Attia, 2014). To reach this state the body must deplete all glucose stores including those in the liver. This can be accomplished through periods of fasting or through intake of high fat and minimal carbohydrates and sugars. Both sugars and carbohydrates are converted to glucose for the body to burn as energy or ATP. When the body is starved of glucose it must switch gears in order to continue its existence. This switch of gears is what followers of the ketogenic diet call fat assimilation. The human body under the realization that there are no stores of glucose for energy asks the liver to create ketone bodies. Those ketone bodies use lipids or fat for energy. This is the greatest benefit for dieters since the goal for most is to lose weight through fat loss.

Carbohydrates, fats and proteins are three energy-yielding nutrients. They can also be called macronutrients. Carbohydrates are energy-yielding nutrients because they provide four kilocalories per gram. Carbohydrates can include starch and sugar. Fats or lipids can provide nine kilocalories per gram. They are a form of energy that is concentrated. Proteins provide four kilocalories per gram. When someone eats these three macronutrients and they do not use energy right away, it is stored as fat in the body. If someone is very active, they will use the macronutrients as their energy. If someone takes in an insufficient amount of protein, the person will store it but will then make the person lose body weight because it

The Ketogenic Diet switches a body’s main metabolism- from utilizing glucose, to a main fat-based energy source (“Ketogenic Diet” 15). Without the carbohydrates to burn, the body simulates the burning of fat (much like that of a fasting person) that leaves a residue in the form of ketone bodies. The beta-hydroxybutyric acid in the Ketone bodies are "metabolized" by the liver and the brain to be used as an energy source (“Ketogenic Diet,” 16). When the ketone bodies are metabolized by the brain, it slows down the brain activity, which could possibly control the seizures of an epileptic. In comparison to fasting, the ketogenic diet serves as a long lasting fat burner as it switches the metabolism from burning carbs then burning fat, to over burning the little amount of carbohydrates to fat burning (as if the carbohydrates weren’t even there to burn). This is also why the patients who stop the diet after a long period of time still receive the benefits as if they were still on the diet, as the metabolism would still be burning the fat

Carbohydrate is a nutrient essential for energy production and the prevention of ketosis, a state where the production of ketones exceeds metabolism. Protein is a nutrient essential for its components, amino acids. Fat is a nutrient which provides insulation, protection and energy for the body.

There are two metabolic states defined as, 'Absorptive,' and, 'Postabsorptive,' which are defined by the time that has elapsed since the person has taken in food and the changes in their body's energy processing. The, 'Absorptive,' state lasts around four hours both during and after a person has eaten a meal. During the absorptive state the person's body absorbs nutrients they have consumed, uses some of them to meet their immediate needs, and converts excess nutrients into energy that is stored. The absorptive state is regulated largely through a hormone called, 'Insulin,' that promotes cellular uptake of glucose, or blood sugar, as well as amino acids, glucose oxidation, the synthesis of fat and glycogen. Due to quick cellular uptake of glucose,

Excess glucose is converted to glycogen for storage by the liver and skeletal muscles after meals. Glycogen is gradually