What exactly is metabolism?

Many people believe metabolism is just your ability to burn calories and be skinny.Or they understand it as “resting energy expenditure”. This is a misunderstanding ; one which most of the fitness industry still perpetuates. 

What it is really; is the sum total of all processes in the body. Metabolism is the term used collectively for all physical and chemical reactions that occur in the body. 

Metabolism includes catabolic (breakdown of substances or tissue in the body ) and anabolic (tissue-building) processes in the body. 

Constantly the fitness industry is trying to simplify everything. Especially the calories in vs calories out brigade. If it was this simple everyone who dieted or eat less food would look like a greek god. 

If your metabolic pathways are out of balance like many peoples are, then this can create problems with the ability to loose or gain weight, fat or muscle. Energy levels and chronic fatigue, inability to increase strength plus a host of other health problems will be prevalent. 

The human body is complex and we must first begin to understand the web of factors that can influence metabolism. How our genes express themselves is very dependant on how we live our lives. Eating, sleeping, exercising, conflict or stress , love and all activities are involved in managing ways in which our genes express themselves. 

Three factors which drastically affect  your metabolism is the level of stress you are under and stress management, the endocrine glands and blood sugar / insulin balance. 

The endocrine glands are the masters of metabolism. They direct activities within the body by releasing chemical messengers, called hormones into the bloodstream. More than fifty hormones regulate our mood, metabolism, sexual function as well as growth of new tissue, breakdown of tissue and the development of many other functions. The major endocrine glands are the the pituitary gland, the hypothalamus, the thyroid glands, the adrenal glands and the pancreas. I will in future blogs go into more detail.

For this blog I will explore the thyroid gland. 

The thyroid gland is a small butterfly-shaped gland in the neck and is the biological engine that ultimately directs hormonal function and therefore metabolism. The thyroid gland produces the hormones that make the body burn calories. Thyroid hormones are what drive your basal metabolic rate(the energy required for internal cellular work when the body is at rest, which is metabolism). 

T4(Thyroxine/a thyroid hormone) increases basal metabolic rate by impacting on the rate of ATP(energy) production in the mitochondria (the energy producing components of cells). 

Several nutrients are critical for optimal functioning of the thyroid gland. It needs trace elements of iodine, chromium, selenium, zinc and amino acid tyrosine. Without sufficient supply of these nutrients in the diet thyroid function is diminished. Two other minerals help reduce the stress on the thyroid and nourish the thyroid – these are magnesium and calcium. I will explore these two minerals further in future blogs.  

The stress hormone cortisol strips and depletes tyrosine because it is needed to produce cortisol. Thus taking away from the thyroid glands. Chronic stress inhibits T4 conversion to T3 (thyroid hormone T4 is converted to T3 prior to any cellular metabolic activity) this in effect slows down metabolism. 

The thyroid plays an extremely important role in optimal or sub-optimal function of metabolism. The thyroid is responsible for releasing hormones that dictate how well your cells release carbohydrates for energy, protein synthesis and the use of fatty acids. Low thyroid function slows metabolism leading to depleted energy and slower metabolic rate that leads to weight gain or difficulty losing fat ; especially around the belly. 

The thyroid is the biological engine and is a point of interest if your goal is weight loss. Signs your thyroid isn’t functioning well are : cold hands and feet, brittle hair, skin and nails, aching muscles, poor appetite, intolerance to cold weather and difficulty loosing weight or fat. The aim with nutrition and supplementation should be to up-regulate and nourish the thyroid. Stress plays a substantial role on how the thyroid functions, so being proactive about daily activities that are relaxing is paramount. Yin yoga, meditation, massages and time in nature is the best path in my opinion.

Five foods that can aid optimal thyroid function : 

Roasted seaweed, seaweed, such as kelp, nori, & wakame, are naturally rich in iodine—a trace element needed for normal thyroid function. Eat seaweed with sushi or get packaged seaweed snacks to toss in salads.

Salted nuts, brazil nuts, macadamia nuts, & hazelnuts are excellent sources of selenium, which helps support healthy thyroid function. Pack a small bag of assorted nuts to snack on throughout the day.

Baked fish and most fish are rich in Omega-3 fatty acids & selenium, which both help decrease inflammation. Bake salmon, cod, sea bass, haddock, or perch for lunch or dinner to get a healthy dose of Omega-3s & selenium.

Frozen yogurt. Dairy products like yogurt contain iodine. The thyroid needs iodine to prevent its glands from becoming enlarged—known as goiter. Treat yourself to a low-fat serving of frozen yogurt to get sufficient levels of iodine. To killl two birds with one stone aim for kefir yogurt which contains plenty of probiotics which supports gut health. 

Fresh eggs. Eggs contain healthy amounts of both selenium & iodine. For the most health benefits, eat the whole egg, as the yolk holds most of the nutrients.

Here are 5 tips to help create a better balanced metabolism.

  1. Stop doing HIIT workouts (these type of workouts should make up the bare minimum in your weeks training – due to the excessive stress it causes on the thyroid and adrenals. Not all types of exercise is created equal). 
  2. Increase the amount of strength training you do per week. (Strength stimulates anabolic hormone production which helps to increase thyroid activity – you do not get this same boost from HIIT type workouts). 
  3. Remove caffeine from your diet. It wreaks havoc on the adrenals and thyroid system.
  4. Reduce sugar intake . Another factor that screws around with energy levels.
  5. Spend more time outdoors in the sun in nature. 

The “PMF health assessment questionnaire” which give’s me a considerable insight into the physiological health of the client is a tool I used to asses metabolic function with clients – it’s 11 pages long. 

So even before I create any programming or nutrition advice to the client they would need to complete 11 pages of very in depth questioning.

For further details or  to book a consultation please click the link below :


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