1. Discuss ways in which the body's metabolism adapts to conditions of fasting/starvation. How do these adaptations affect the rate of weight loss when dieting?
Metabolism is defined as the sum of all the chemical reactions that go on in living cells. These chemical reactions include the making and breaking of the bonds in carbohydrates, fats, and proteins; how the body obtains and uses energy from foods, or energy metabolism. During the process of metabolism, the body releases energy, water, carbon dioxide, and other waste products. (Whitney & Rolfes, 2016, p. 202).
Healthy diets deliver necessary kcalories of energy from carbohydrate, fat, and protein that fuels physical activity and metabolic work of the body. During fasting or starvation, …show more content…
List the major components that contribute to the body's daily expenditure of energy. Compare the relative contributions of a sedentary person with a marathon runner of the same body weight.
People not only expend energy when they are involved in physical activities, but also when they are resting. Thermogenesis, the generation of heat caused by energy expenditure in the body, can be reflected in three main categories: energy expended for basal metabolism, energy expended for physical activities, and energy expended for food consumption. A fourth category is sometimes involved, which includes energy expended for adaptation (Whitney & Rolfes, 2016, p. 240). Energy needed to maintain life when the body is at complete digestive, physical, and emotional rest is called basal metabolism. Accounting for approximately two-thirds of the energy a person expends daily, basal metabolism includes the activities of the lungs inhaling and exhaling air, bone marrow making new red blood cells, the heart beating, and kidney functions; the basic processes of life. The rate at which the body expends energy for these functions is the basal metabolic rate (BMR). Although the rate varies from person to person based on physical conditions, BMR is slowest when a person is sleeping undisturbed. In general the more an individual weighs, the m ore energy is expended on basal metabolism. Additionally, BMR may be higher in individuals with fever, under stress, or with highly active thyroid glands, while …show more content…
When an individual eats, the GI tract muscles speed up their contractions, digestive juices are secreted, and energy is used for absorption of nutrients, all these actions use energy and create heat. The TEF is proportional to the amount of food energy taken in, usually estimated a t 10 percent of energy intake. Size and frequency of meals also influence the thermic effect of food and high protein foods produce a greater thermic effect than high fat foods. The thermic effect of food contributes very little to an individual’s overall energy expenditure (Whitney & Rolfes, 2016, p. 241). Lastly, additional energy is expended when circumstances in an individual’s body drastically change. The body must adapt to instances of physical conditioning, extreme heat or cold, starvation, or even trauma. These extra stresses on the body require extra energy to build tissue and produce enzymes and hormones necessary to deal with the new demands on the body. This extra energy expenditure is known as adaptive thermogenesis, and varies specific to individuals, therefore not often included in estimation energy requirements (Whitney & Rolfes, 2016, p.
Metabolism is defined as the sum of all the chemical reactions that go on in living cells. These chemical reactions include the making and breaking of the bonds in carbohydrates, fats, and proteins; how the body obtains and uses energy from foods, or energy metabolism. During the process of metabolism, the body releases energy, water, carbon dioxide, and other waste products. (Whitney & Rolfes, 2016, p. 202).
Healthy diets deliver necessary kcalories of energy from carbohydrate, fat, and protein that fuels physical activity and metabolic work of the body. During fasting or starvation, …show more content…
List the major components that contribute to the body's daily expenditure of energy. Compare the relative contributions of a sedentary person with a marathon runner of the same body weight.
People not only expend energy when they are involved in physical activities, but also when they are resting. Thermogenesis, the generation of heat caused by energy expenditure in the body, can be reflected in three main categories: energy expended for basal metabolism, energy expended for physical activities, and energy expended for food consumption. A fourth category is sometimes involved, which includes energy expended for adaptation (Whitney & Rolfes, 2016, p. 240). Energy needed to maintain life when the body is at complete digestive, physical, and emotional rest is called basal metabolism. Accounting for approximately two-thirds of the energy a person expends daily, basal metabolism includes the activities of the lungs inhaling and exhaling air, bone marrow making new red blood cells, the heart beating, and kidney functions; the basic processes of life. The rate at which the body expends energy for these functions is the basal metabolic rate (BMR). Although the rate varies from person to person based on physical conditions, BMR is slowest when a person is sleeping undisturbed. In general the more an individual weighs, the m ore energy is expended on basal metabolism. Additionally, BMR may be higher in individuals with fever, under stress, or with highly active thyroid glands, while …show more content…
When an individual eats, the GI tract muscles speed up their contractions, digestive juices are secreted, and energy is used for absorption of nutrients, all these actions use energy and create heat. The TEF is proportional to the amount of food energy taken in, usually estimated a t 10 percent of energy intake. Size and frequency of meals also influence the thermic effect of food and high protein foods produce a greater thermic effect than high fat foods. The thermic effect of food contributes very little to an individual’s overall energy expenditure (Whitney & Rolfes, 2016, p. 241). Lastly, additional energy is expended when circumstances in an individual’s body drastically change. The body must adapt to instances of physical conditioning, extreme heat or cold, starvation, or even trauma. These extra stresses on the body require extra energy to build tissue and produce enzymes and hormones necessary to deal with the new demands on the body. This extra energy expenditure is known as adaptive thermogenesis, and varies specific to individuals, therefore not often included in estimation energy requirements (Whitney & Rolfes, 2016, p.