Question

What is the practical significance of an animals metabolic rate from a clinical medicine & nutrition standpoint?

Answer 1

Practical significant of MR : Clinical medicine & nutrition standpoint-

A person who has to eat constantly to keep from losing weight may say they have a “fast metabolism,” while a person who eats only a little and still gains weight may say they have a “slow metabolism.”

However, metabolism isn't something that's unique to humans. In fact, when you get right down to it, metabolism just refers to the sum total of the biochemical reactions that take place in an organism’s body. So, every living thing has a metabolism, from a bacterium to a plant to you!

What, exactly, is the rate of an organism’s metabolism? Broadly speaking, metabolic rate refers to how quickly fuels (such as sugars) are broken down to keep the organism’s cells running. There are general differences in metabolic rate among species, and the environmental conditions and activity level of an individual organism will also affect its metabolic rate.

In this article, we’ll take a closer look at the basics of metabolism and see how metabolic rate can vary among species and depending on circumstances.

Metabolism and heat production

It's probably not news to you that animals (such as humans) need food as a source of energy. But why is this the case?

The molecules in your breakfast, lunch, or dinner have energy stored in their chemical bonds. Some of your body's metabolic reactions, like the ones that make up cellular respiration, extract this energy and capture part of it as adenosine triphosphate (ATP). This energy-carrying molecule can, in turn, be used to power other metabolic reactions that keep your cells running.

Molecules from food are also used as building blocks for the structures of your body. For instance, proteins from your food are broken down into their component parts (amino acids) and may be used to build new proteins in your own cells. If you eat more than enough food to replenish the energy you use, food energy may also be stored as glycogen (a chain of linked glucose molecules) or as triglycerides (fat molecules) for later use.

The business of extracting energy from fuel molecules and using it to power cellular reactions is not a perfectly efficient process. In fact, no energy transfer can be perfectly efficient – that's a basic law of physics. Instead, each time energy changes forms, some amount of it is converted into a non-usable form. In the reactions of an animal's metabolism, much of the energy stored in fuel molecules is released as heat.

This is not necessarily a bad thing! Some animals can use (and regulate) their metabolic heat production to maintain a relatively constant body temperature. These animals, called endotherms, include mammals, such as humans, as well as birds. Ectotherms, on the other hand, are animals that don't use metabolic heat production to maintain a constant body temperature. Instead, their body temperature changes with the temperature of the environment. Lizards and snakes are examples of ectotherms.

Nutritional state: BMR is low in starvation and undernourishment as compared to well fed state. Starvation leads to an adaptive decrease in BMR, which results from a decrease in lean body mass

.Your metabolism speeds up after you eat in an effort to digest food and turn it into energy. Therefore, eating more often can raise your metabolism and speed up your weight loss. However, to avoid packing on the pounds, you want these meals to be smaller in size and calories.

Eating a lot less food can kick your body into what's commonly known as starvation mode — your metabolism slows so you use less energy and burn fewer calories. Your body may also drop muscle mass to conserve energy. Starvation mode tends to leave you feeling hungrier and sluggish.