Metabolic Slowdown and the Influence of Aging

Important Facts About Metabolic Slowdown

It is common to see people experience diverse unpleasant bodily changes, including weight gain, as they grow older. Some might wonder why this has to happen. The interplay of various factors is responsible for these seemingly repulsive changes. Among these causative factors is metabolism – or more precisely, the slowdown of metabolism. This is capable of negatively impacting a person’s quality of life. What do you need to know about metabolism? What causes its slowdown and what can be done to ramp it up? Get the answers here. Metabolism

What is metabolism?

Metabolism is a term used to describe some chemical reactions occurring in the body and through which life is sustained. In other words, it refers to chemical transformations taking place within living cells of organisms helping to maintain the living state of these cells and the organism. It is the process through which the body is able to convert food consumed into energy for use. In addition to converting food into energy to facilitate cellular processes, metabolism helps to convert the food you eat into building blocks of proteins, nucleic acids, lipids and certain carbohydrates. It also plays a crucial role in the elimination of nitrogenous wastes.

It is typical to broadly categorize metabolism into two, namely: catabolism and anabolism.

Catabolism – This refers to the set of metabolic processes by which large organic matter or molecules are broken down to provide energy for the body. It usually involves the breakdown of complex organic molecules into smaller, simpler molecules, such as water and carbon dioxide. In addition to helping to supply energy, catabolism also assists in the provision of requirements for anabolism to take place.

Anabolism – This is the set of metabolic processes geared towards the synthesis of complex molecules or compounds required by body cells. These complex molecules are synthesized using the energy produced by catabolism. Anabolic reactions occur in stages. The process starts with the production of precursors, including amino acids and monosaccharides, and then moves on to the activation of these through ATP energy into reactive forms. The precursors are assembled into complex molecules, such as proteins, lipids and polysaccharides, in the final stage.

The chemical conversions involved in metabolism are categorized into metabolic pathways, which enable the transformation of basic chemicals into other chemical forms via a series of steps by a sequence of enzymes. These pathways depend on nutrients from food to release energy. In order to enjoy a healthy life, a fine balance between catabolism and anabolism must be in place. Failure in this regard will tell, among other things, on body weight. You should expect to lose weight when the energy used by the body exceeds that consumed (in form of calories); weight gain is experienced when the reverse is the case.

Understanding metabolic slowdown

Metabolism does not stop. It continues even when your body is at rest or you are asleep because it needs to generate energy needed for breathing, blood circulation and cell repair, among other functions. Metabolic rate, or speed of metabolism, determines how much food a person requires as well as how that food is obtained. You may also think of it as the amount of calories needed by your body to carry out diverse functions. The number of calories used for these diverse processes when the body is at rest is commonly described as basal metabolic rate (BMR). This depends greatly on the extent of a person’s body weight and muscle mass. You burn more calories – have faster metabolism – when you have more muscles than fats in your body. It is estimated that the body burns about 35 calories for every pound of muscle when at rest, while only two is burned per pound of fat.

At some point, a person may experience slowdown in metabolism and this could possibly have serious consequences. This happens as a result of diverse factors. Aging is mostly held responsible for the lower metabolic rate that is experienced. It has been observed that metabolism starts to slow as soon as puberty is over. As people grow older, they typically gain body fat and experience a loss in muscle mass. You may recall that muscles cause a person to burn calories faster by speeding up metabolism. It then follows that when you have low muscle mass, fewer calories will be burned; hence, you tend to have a low metabolic rate.

Although aging is the major reason for slowdown of metabolism, it must be noted that this phenomenon does not occur at the same rate in men and women.

Metabolism in men

Metabolic rate in men usually does not decline at a very fast rate. You may easily guess why this is so based on the foregoing explanation. Men tend to have more muscle mass than women, enabling them to burn more calories. In addition, they have larger organs than their female counterparts. Metabolism is generally at its best during the teenage years when a young man is undergoing significant growth and development. At this stage, he may eat anything without any fear of weight gain since the body is still able to burn fat more efficiently.

This, however, changes after the age of 30 – sometimes, even before attaining that milestone. Metabolic rate is said to drop about one percent every four years after reaching the age of 20. But it is possible some men might not notice these changes until they are around the age of 40. It is projected that a man will lose muscle mass at a rate of around one percent each year after attaining the age of 45. This further causes your caloric needs to drop and your metabolism to follow suit. By the 50s, a man who has been experiencing metabolic slowdown for a while starts to show considerable physical manifestations, including wrinkles and certain cancers.

Metabolism in women

Women make up the group that is likely to be affected the more by low metabolic rate with the passing of time. As in the case of men, they tend to experience their best metabolism in the teenage years. Expert says females enjoy their best basal metabolic rate in late teens to early twenties. Less muscle mass, however, means that not as much calories is burned as men in most stages of life. On average, a man has about 10% higher BMR than a woman.

From late-twenties onward, a good number of women tend to be more mindful of the sort of food that they eat. This is often done to guard against weight gain, a possible effect of slow metabolism. It is not unconnected with the fact that most people tend to be less active as they grow older when a significant number of hours in the day are spent in a chair. This causes muscle mass to decline, while fat increases. You lose about one percent of your muscle mass each year as a woman when in your 30s.

Pregnant women may experience an improvement in metabolism if they had healthy weight previously and do not see their state as an opportunity to eat all they desire. Breastfeeding also offers another opportunity for women to burn up to 1,000 calories per day. The problem of slow metabolism becomes more pronounced from the 40s when the levels of certain vital hormones start to experience a slump. It becomes quite hard to keep off weight from this period on. Muscle loss and weight gain resulting from slow metabolism get especially worrisome at the onset of menopause.

In addition to the gender aspect to metabolic slowdown, differences in the speed of metabolism also exist between individuals. It is commonsense that a person with a higher BMR will usually burn more calories. How active a person is will determine their metabolic rate. Also, it is believed that someone can be born with slow metabolism, but this can be improved upon by taking appropriate steps.


Roles of hormones in metabolism

Hormonal changes contribute to slow metabolism – in connection with other factors. Thyroid hormones especially play crucial roles in the regulation of metabolism. As a matter of fact, metabolic slowdown is sometimes referred to as hypothyroidism. The thyroid gland produces T3 and T4 hormones, the former of which exerts the greater influence although in lower quantity in the blood. A fall in active thyroid hormone levels results in metabolic slowdown. This may be caused by a decline in lean muscle mass and elevated cortisol levels (as a result of stress) as well as increased insulin production.

Human growth hormone is another substance that has been connected to metabolic slowdown. It is highly useful for metabolism of proteins, carbohydrates and lipids. The effect of HGH is believed to be both direct and indirect in nature. It has been shown to directly impact on metabolism and also indirectly through the action of insulin-like growth factor-1 (IGF-1). The levels of this master hormone drop with the passing of the years bringing, among other issues, a slowdown of metabolism.

Fall in the levels of other types of hormones exerts negative impact on metabolism as well. These other hormones include adrenaline, nor-adrenaline, estrogen and progesterone.

Effects of metabolic slowdown

There is seemingly nothing beneficial about the drop in metabolic rate that you are expected to experience as grow older – more especially so if you are a woman. Failure to take prompt steps to combat slow metabolism exposes you to risk of serious medical conditions or illnesses. Let us consider some of these.

Elevated blood cholesterol levels – Experts say a person suffering from hypothyroidism is more likely to experience certain ailments connected to the liver, an organ which helps with the breakdown of fats. An unhealthy liver raises the risk of fats, more particularly, cholesterol, accumulating in the blood. High levels of low-density lipoproteins (LDL) – what most people prefer to call “bad” cholesterol – and triglycerides could result in cardiac issues, such as heart attacks and high blood pressure. Elevated cholesterol levels causes hardening of arteries, a condition known as atherosclerosis.

Poor circulation – Slow metabolism could adversely affect the flow of blood in your body. This poor circulation mostly affects fingers and toes. Sadly, this could cause you to develop a condition called Raynaud’s Disease.

Diabetes – A person with slow metabolism may have issue of elevated blood sugar with time. Poor digestion, ineffective circulation and body fat accumulation can give rise to Type 2 diabetes. This, in turn, could lead to several other worrisome medical conditions.

There are other side effects that have been associated with metabolic slowdown as well. Obesity or weight gain is one of these, although Dr. Donald Hensrud of Mayo Clinic says slow metabolism is rarely the cause of this. High blood pressure, chronic fatigue and excessive perspiration are also among the possible effects of a low metabolic rate.

How to raise metabolism

Exercises and strength training are recommended for those who are looking to ramp up their metabolic rate. And of course, the importance of diet in this regard cannot be overemphasized as well. It stands to reason that you should not expect metabolism to improve if you continue eating the same things and not getting any more active.


It is advisable to start working on maintaining healthy metabolism as soon as you turn 30 – better if you start earlier. Men in their 30s will benefit greatly from strength training that pushes them hard. Workouts involving the use of kettlebells are especially recommended. Effort should be made to eat more lean proteins, fruits, vegetables, fish and low-dairy products. Supplements containing omega-3 fatty acids, DHA and EPA are useful for keeping metabolism issues at bay. Multivitamins that include vitamins B, D and E, antioxidants such as lycopene and lutein, and calcium will be beneficial to those whose diets are not up to notch.

Endurance training, including swimming and running, will be advantageous to those men in their 40s. It has been shown that interval training in particular improves fitness while helping to build lean muscles and burn body fat. You will need to allow for sufficiently long time at this stage to recover from workouts so as to guard against muscle loss. Attempts should also be made to keep stress well under control. Highly-demanding workouts will be counterproductive for men aged 50 and over. Some cardio exercises and occasional weight training will suffice. Older men are usually advised to engage in prehab exercises which help to improve movement and posture as well as prevent injuries. Proper sleep and testosterone supplementation are equally helpful to boosting metabolism.


A healthy diet and regular exercise are also the secrets to keeping metabolism in a desirable state in women. Ideally, you need to have these aspects well-covered at every stage of life. You may get away with eating junks when younger without adding unsightly weight. Exercise and healthy diet becomes non-negotiable as soon a woman enters her 30s. From this point on, it is advised to add strength training to your routines at least a couple of times per week. This is particularly more important because women tend to lose muscle mass faster than men, exposing them to risk of a metabolic slowdown. Research has shown that those who lift weights are less likely to have belly fat as they grow older.

It may well be correct to say that women make up the group most in need of strength training. The fact that they lose muscle mass faster is the reason for this. Older women will get significant assistance in building muscles by increasing protein intake to around 100-120 grams per day. Proteins help to keep hunger under control and provide the building blocks needed by your muscle tissues. In addition to engaging in strength training and increasing protein consumption, it is important to cut down on sugar and carbohydrates to raise metabolism.

The above is just a snapshot, in a way, of how you can go about boosting your metabolism. There are numerous other steps that can be taken and which can help in different ways to achieve the desired goal. They include:

Your life and wellbeing depends on your metabolism to a significant extent. Aging can impact on this and, by extension, produce dire consequences on certain functions in the body. While both sexes can experience metabolic slowdown, it is usually more pronounced in women. The disruption in these life-sustaining chemical reactions may be caused by hormonal changes, inadequate sleep, poor diet, dehydration and sedentary lifestyle to mention a few. Strength training is highly essential when looking to raise your metabolism. This should be complemented by a healthy, protein-rich diet and use of supplements containing omega-3, vitamin B, vitamin D and antioxidants.




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