How Does Metabolism Affect Weight?

How Does Metabolism Affect Weight?

You likely know your metabolism is linked to your weight. But do you know metabolism affect weight?

Common belief holds that a slim person’s metabolism is high and an overweight person’s metabolism is low. But this isn’t usually the case. Metabolism affect weight by itself.

Weight is dependent on the balance of calories consumed versus calories burned. Take in more calories than your body needs, and you gain weight. Take in less and you lose weight. Metabolism, then, is the engine that burns these calories and is the scale that regulates your energy needs.

Diagram how Metabolism Affect Weight

When Will Metabolism Affect Weight?

Stated simply, metabolism is the process by which your body converts food into energy. During this biochemical process, calories – from carbohydrates, fats and proteins – are combined with oxygen to release the energy your body needs to function.

The number of calories your body burns each day is called your total energy expenditure. The following three factors make up your total energy expenditure.

1. Basic needs. Even when your body is at rest, it requires energy for the basics. Fuel for organs, breathing, circulating blood, adjusting hormone levels, plus growing and repairing cells.  Calories expended to cover these basic functions are your basal metabolic rate.

Typically, a person’s basal metabolic rate is the largest portion of energy use, representing two-thirds to three-quarters of the calories used each day. Energy needs for these basic functions stay fairly consistent and aren’t easily changed.

2. Food processing. Digesting, absorbing, transporting and storing the food you consume also takes calories. This accounts for about 10 percent of the calories used each day. For the most part, your body’s energy requirement to process food stays relatively steady and isn’t easily changed.

Male and Female Symbols3. Physical activity. Physical activity accounts for the remainder of calories used. Examples are playing tennis, walking, chasing after the dog and any other movement. You control the number of calories burned depending on the frequency, duration and intensity of your activities.

It may seem logical to think that significant weight gain or being overweight is related to a low metabolism. Perhaps you feel a condition such as under-active thyroid gland (hypothyroidism) is at fault. In reality, it’s very uncommon for excess weight to be related to a low metabolism. And most people who are overweight don’t have an underlying condition, such as hypothyroidism. A medical evaluation can determine whether a medical condition could be influencing your weight.

Weight gain is more likely due to an energy imbalance – consuming more calories than your body burns. To lose weight, then, you need to create an energy deficit by eating fewer calories. You then need to increase the number of calories you burn through activity. This is how metabolism affect weight.

If you and everyone else were physically and functionally identical, it would be easy to determine the standard energy needs. But many factors influence calorie requirements, including body size and composition, age, and sex.

To function properly, a bigger body mass requires more energy (more calories) than does a smaller body mass. Also, muscle burns more calories than fat does. So the more muscle you have in relation to fat, the higher your basal metabolic rate.

As you get older, the amount of muscle tends to decrease and fat accounts for more of your weight. Metabolism also slows naturally with age. Together these changes reduce your calorie needs.

Men usually have less body fat and more muscle than do women of the same age and weight. This is why men generally have a higher basal metabolic rate and burn more calories than women do.

Your ability to change your basal metabolism is limited. However, you can increase daily exercise and activity to build muscle tissue and burn more calories.

Your metabolism influences your energy needs, but it’s your food intake and physical activity that ultimately determine your weight.

Losing weight, like any task you undertake, requires that you have dedication and motivation to succeed.  This means you need to get your head in the right place.

You may also like…

Metabolism 101

Metabolism 101

Metabolism is the rate at which we burn the calories that we have consumed during each day. There are a number of factors that determine the speed of your metabolism.

Metabolism Factors


Metabolism food factor
Metabolism food factor

The first factor in the speed of your metabolism is the food you eat. Determining factors are:

  • How many meals you eat.
  • What kind of food you eat.
  • How much you eat during each sitting.

All of these factors can be changed to improve your metabolism.

Lean Body Mass

Some people are born able to carry more lean body mass (muscle) than others – without exercising. For the rest of us, proper exercise can increase our lean body mass substantially. The more fat your body has, the slower your metabolism will be. By exercising and building muscle you will both decrease your body fat, while increasing your lean body mass. So itʼs a win win situation.


As we age, our metabolism naturally slows down. Studies tell us that after the age of 20, our bodies will lose 1/3 to 1/2 pound of muscle tissue per year if we do not exercise on a regular basis. Losing 1/3 to 1/2 pound of muscle every year after the age of 25 causes our percentage of body fat to rice significantly.

Increasing Metabolism

Because our bodies are made for survival it begins to hoard fat if it feels like it wonʼt get food for a long time. Basically, if you starve your body it will go into starvation mode. Our bodies are made to first use the nutrients in the food we eat for energy.

When the nutrients run out, the body resorts to energy from the muscles (you will lose lean muscle mass), then finally your body resorts to the bodies fat supply. This is why fad diets never work.

  • Eat More. Eat Often.This doesn’t mean sit down and pig out! This means eat smaller meals throughout the day – preferably 5 to 6. The combination of small balanced, frequent meals allows your body to utilize the nutrients it needs when it needs them. Smaller, more frequent meals stimulate your metabolic rate as your bodyʼs digestive system works and you maintain a stable glucose level. This will give you more energy, prevent hunger pains and keep you from binging.

    Lifting Barbell Weights
  • Workout With Weights.
    Weight training is a great way to increase your metabolism. Lifting weights places a high demand on your body to burn more calories for faster growth and recuperation. Your muscle mass is the single most important factor in determining how many calories you burn because itʼs a very metabolically active tissue. The more muscle you have, the more calories you burn – even at rest.  Consider our manual, Working Out With Weights.
  • Aerobic Exercise. You should perform some type of aerobic exercise at least 3 times per week and youʼll not only burn calories, but also speed up your metabolism. Always keep this in mind while doing your cardiovascular exercise.

See also: Using Nature to Boost Metabolism