What is Metabolism and its Relationship with Body Weight

If you’ve landed on this article, you’re probably trying to understand how to use your metabolism to change your weight. In this article, we’ll be discussing the basic metabolism definition and how it affects your weight. We hope it’ll help you have a better understanding of your body and how it works.

What is metabolism?

Your metabolism is a catch-all phrase for all the chemical processes going on in your body to turn food into energy so that your body can keep functioning. This includes the digestion of food and using energy to repair or grow cells.  

When you eat or drink something, your digestive system breaks down the carbohydrates, fat and protein from it, and transforms it all into energy that the body can use. This is the most simple definition.

So how does this definition help you lose weight? It’s all a matter of how efficiently your metabolism works.

The relationship between metabolism and body weight

Weight gain or weight loss is a simple equation that can be defined in terms of metabolism. If we regularly consume more food than our metabolism requires for optimal functioning, the energy is largely stored as fat. Conversely, if we do not get enough nutrition or energy from the food we eat, we lose weight.

The relationship between metabolism and weight is more apparent as people grow older. The classic healthy definition works fast and efficiently. As you get older, your metabolism slows down, causing weight gain or slower weight loss.

The amount of energy that your body can break down and use is largely determined by your metabolism. Most of the energy is used to ensure that all bodily systems are running smoothly, and you don’t have much control over how your body chooses to do this. However, you can control how fast or slow your metabolism works and this is what can change your weight gain or weight loss strategy.

What is metabolism speed and how can I speed it up?

Your metabolic speed (also known as metabolic rate) is the speed at which your body consumes energy to power its daily activities as well as its regular growth and repair. If it is sluggish, it cannot convert the calories you eat into energy and so your body stores it as fat.

Some foods are said to boost metabolism (such as green tea, etc.) but you would have to consume extremely large amounts of these foods to gain those benefits. The scientific evidence is scant for the efficacy of taking foods or supplements specifically to boost your metabolism.

The most effective way to lose weight through metabolism is with physical activity. You cannot alter your natural metabolic speed but when you do any form of physical activity, your body is forced to consume more energy.

Physical activity is the sole component completely under our complete control. It accounts for 20-25% of our metabolism. The best recommendations for this are aerobic activities such as walking, cycling and swimming. Strength training can further fire up the metabolism by increasing muscle mass.

The healthy cycle of an efficient metabolism

The more physical activity you engage in, the more calories you burn. So while you lose weight, your body is also revving up the metabolic rate to work better all day.

An article by Time magazine showed how a morning workout is the best way to do this. In the morning, the higher levels of cortisol and growth hormones in your system help your metabolism draw energy from fat reserves.

To put it simply: if you work out in the early hours of the morning, you’ll burn fat more effectively and will also experience reduced appetite and cravings during the day. That means you’re unlikely to crave junk food snacks in the middle of the afternoon if you work out that morning.

What is metabolism efficiency for older people?

As we age we may become less active. This has a slowing effect on our metabolic processes, so you may notice some weight gain and a feeling of low energy. If your food intake remains the same, you’re likely to put on weight.

An effective way of increasing metabolism as you get older is through strength and resistance training. This kind of special training builds and maintains lean muscle mass. Muscle tissue consumes more energy than fat tissue, so if you have more muscle mass, your metabolism stays functioning at a good speed.

What are the factors that affect my metabolism?

Your metabolic rate is determined by several factors. These include:

• Composition of the body: Bodies with more muscle tissue tend to have higher rates of metabolism. Fatty tissue in the body burns the least amount of energy, thereby slowing your metabolic rate.
• Fad dieting: If you go through sudden periods of reduced food intake, your body metabolism may slow down to conserve energy for these fasting or starvation periods. This means you may lose less and less weight with each diet.
• Age: The chemical and hormonal changes in your body as you get older will have a slowing effect on your metabolism.
• Gender: It has been found that males have a higher metabolic rate than women.
• Genetics: Genes play a huge role in determining your final metabolic rate.
• Hormonal and nervous systems: These two systems play a major role in determining your metabolic rate, and any imbalances may have a strong impact.
• Environmental temperature: Extremely high or low temperatures force the body to work harder, thereby increasing the rate of metabolism.
• Infection, injury or illness: When the body has to work harder to build new tissue or fight off infection, it may push your metabolic rate higher.
• Physical activity: No surprises here; higher activity levels lead to a higher metabolism.
• Drugs: Consumption of caffeine and nicotine is known to boost metabolism.

Does my health affect my metabolism?

Yes, your state of health has a prominent effect on your metabolism and vice-versa.

Certain conditions can speed up metabolism and cause weight loss while some conditions reduce it so much that it may lead to obesity. In the same way, your metabolism has an impact on your health.

Hormones also play a key role in determining metabolism. Two of the most common disorders of the thyroid affect the secretion of hormones that govern metabolic processes. These are:

Hypothyroidism: This is an under-active thyroid gland that lowers the metabolism due to a lack of enough hormones. The usual symptoms of this condition include unusual weight gain, lethargy, depression and constipation.

Hyperthyroidism: Conversely this is an over-active gland that secretes abnormally high quantities of hormones than required and speeds up the metabolism. Some of the symptoms of this condition are increased appetite, weight loss, nervousness and diarrhea.

Apart from these conditions, you may be prone to disorders of the metabolic system if you have conditions such as heart disease, diabetes and kidney disease through the following mechanisms.

Important phrases that you should know

The metabolism definition has two important phrases or factors that you should know if you are talking about it. These are:

Basal metabolic rate (BMR): This is the energy expended when you are in a state of complete rest. You may think that sitting still or lying down requires the least amount of energy but in reality, BMR accounts for the highest amount of expended energy at 50-80% of daily energy consumption. The energy is expended to allow all systems to function smoothly and effectively.

Thermogenesis: Also known as the thermic effect of food, this is the energy the body expends on digesting the foods and drinks that you consume. It also includes the absorption, transpiration and storage of the nutrients from this food. It counts for 5-10% of daily usage.

Physical activity: This is the only component of metabolic rate that is under your control. This is the energy consumed by physical movement and it fluctuates the most depending on your level of activities. This includes not only exercising but also all incidental activity such as household chores or fidgeting. This figure can vary widely but averages about 20% of your metabolic rate.

If you would like to know more about eating right for your metabolism, you might benefit from consulting a nutritionist. If you would like to work on your metabolism through physical activity, you should talk to a personal trainer or a yoga instructor. Avaana can help you find any of the above experts.