Building up energy

What is energy, how do we get it, how do we use it ?

People will come to me often complaining of fatigue or low energy. Young adults want to perform better at sports or studies.

Advertisers use strategies as “fortified products”, “enriched in vitamin”, ” mineral RDI for the day”, “energy drink”… Does it really help ? Are fortified products and supplements reliable sources of nutrients?

To understand it, let’s take a closer look to what energy is and its cycle through our body.


The energy cycle.

Energy can be defined as the capacity for doing work. Energy is changing form, could be thermal, electrical, chemical, nuclear or others and therefor is not created but transformed or transferred.(1)

Cells use energy constantly to create building blocks, muscle movement, heat, nervous system functions, homeostasis…

Our energy comes from food, it exists in the molecule’s bounds of macronutrients and it is the deterioration of those bounds that liberate energy which is transferred to other use. It is stored in a compound called ATP (adenosine triphosphate) (2)

A first cyclic exchange of energy was first described in 1937 by a german biochemist, Hanz Arnold Krebs who gave his name to what is known as the Krebs cycle. (3)


The chemical reactions of this cycle will generate divers molecules from the breakdown of glucose molecule. To summarise simply, starting from a glucose molecule, your body needs water, iron, sulphur, CoQ10, the B’s vitamins, vitamin C as well as magnesium, zinc, chromium and other trace minerals.

It is why a balanced diet is necessary to provide the necessary nutrients for body function. Without all necessary nutrients our body is unable to digest the food, breaking down molecule to use the energy presents in bounds.


The molecules resulting from the kreb’s cycle will go through the electron transport chain in the mitochondria for most of our cells.

The final result of a complete energy transfer from citric acid cycle to electron transport chain can be summarised as : Glucose + 6O2 → 6CO2 + 6H2O + 38ATP (4)

The electron transport chain is an exchange of electron between the co-enzymes NADH and FADH2 to oxygen during the oxidative phosphorylation process. (5)

Phosphocreatine is another molecule which is created from excess ATP and can be used to replenish ATP when needed. (6)

Most of our energy sources stored in our body are glycogen in muscle, triglycerides in muscles and adipose tissue and our own muscles protein. ATP and PCr are not stored and need to be released constantly at different rates depending on needs.

Anaerobic respiration is another way of transferring energy. In our muscle it will be done by lactic acid fermentation for a brief period of time during high intensity exercise for example. The accumulation of lactic acid can cause sharp pain or muscle contraction failure. (7)

It is why learning how to breath during exercising is as important as the diet to increase performance and avoid oxygen failure leading to cells switching from aerobic to anaerobic respiration.


Feeling of having energy or not.

A feeling of lack of energy will be the result of a low energy diet, badly managed oxygenation, dehydration or an internal issue into transferring energy from food to cellular use.
Being anaemic will result in having a lack of oxygenation due to low red blood cells count and therefor using more anaerobic respiration producing lactic acid for example. The blood PH will become more acidic and hyperventilation will occur.

Lately, research focused on mitochondria malfunctions linked to chronic fatigue among other related disease. It has been now accepted that people can suffer from mitochondrial damages caused by free radicals and leading to lack of ATP release, therefor to chronic fatigue. (8)

Free radicals are molecules created as bio products from enzymatic reactions and from outside pollutants like cigarettes for example. They attack our cells blocks (lipid, protein, DNA..) in order to steal electrons which could be sumurize as oxidative damage leading to inflammation, cancer, neurological disfunction, ageing… A diet full of antioxidants and low in pollutant will effectively help getting a positive balance between free radical production and excretion.

So, what food should we consume for optimal energy circulation ?

How food gives us energy and when is it too much.

We understand now that our body gets energy from food breakdown and that most nutrients are necessary for the different bio chemical process releasing energy.

Each of our organs will need different source of energy, brain is thriving on glucose and our muscles can use glucose, fatty acids or ketone bodies as fuel sources and the heart will thrive more on fatty acids. Depending on activities and time it is responsible to understand your body needs to get all your organs energy at their best. (9)

Carbohydrates is the primary source of glucose. So why is refined sugar the worse source of carbohydrate? When the molecule is already available without other nutrient, the amount in blood will be to high and then stored in fat for later use. It is especially true for high fructose (high fructose corn syrup for example) food. It is also essential that the sugar molecule is part of a greater chain with a complex micro nutrient content for a better use.  Some research proved the danger of high fructose consumption in people prone to type2 diabetes due to possible genetic mutation. (10)

It is safe to say that whole grain food, legumes, fruits and vegetables are the best sources of carbohydrates as lower in fructose, higher in fibres and essential nutrients compare to refine products. The longer chain rich in fibres will allow the body to digest slowly the food and get a supply of glucose for a longer period of time.

Fat is the second most important sources of energy and is also the one used when prolonged exercising. By training you will increase the number of mitochondria and muscle myoglobin for a better oxygenation and therefor fat metabolising. (11)


Protein can be a source of energy under prolonged fasting. However its main function is to release amino acids necessary for enzymatic reactions and therefor energy release of food. Intake of a large amount of protein can have a adverse effect on the liver and kidneys due to nitrogen excretion and possible uric acid elevation. (12)

When people want to lose weight they have the tendency on cutting one major food group, the result will be weight loss of course but nutrient depletion as well, leading to mitochondrial damages and possibly inflammation and disease. having a balanced diet with a negative energy balance will lead to weight loss with less adverse effects, meaning the calories from food will be lower than the daily activity energy and still the body will get nutrients necessary for body functions.

It is essential to understand what sources of energy has to be targeted in order to lose weight efficiently.(13)

Diet for athletes.

There has been a lot of misleading on sport performance and endurance talking about protein.

Carbohydrates should still be the main source of energy and count as 65 % of an athlete daily calorie intake, which should exceed 3000 a day.

4 to 6 hours before exercising the athlet should consume a pre exercising meal as glycogen metabolism and storage in liver and muscle from complex carbs takes up to 4 hours. Plus a snack every 30 minutes during exercising (50g carbs and 5 to 10gr protein) for a greater carbohydrate and amino acids supply during and at the end of exercising.

For longer stretch of exercising athletes should drink glucose/electrolytes drinks for blood glucose level, hydration and negative side effects of exercising. Every 15 to 20 mins (better make your own than the commercial ones)

Hydration is of course essential as to replace fluids lost during effort.

The main target of an athlete is to teach the body how to store a greater amount of glycogen in muscle and to improve aerobic and anaerobic respiration. (14)


What is the best  for energy then ? 

Food has to be well balanced and consume regularly during the day in order to release the necessary nutrients to the body. Whole food has been proved to be the best as molecules will be more efficiently used by the human body with less waste.


Meditative note.

Our research are usually focused on one side. The body works on its whole and the understanding of the global process of living individuals is crucial in the knowledge of diet and lifestyle choices.

It is the combination of genetic, surrounding factors and stress factors that will guide you in your exercise and food choices. Do not forget that all human being are different.

The balance in between energy exchange, free radicals formation and free radical excretion can be done simply in life by removing most of the toxins and enjoying food and life. You can find in literature really interesting research on genetic and DNA mutation due to external factors. One generation starved during war time and the body learned how to get nutrients more effectively, the next generation will suffer from disease related to too rich food as the body can not take it anymore.

Learn how to chose wisely your pleasures in life, if you are allowed 20 gr of refined sugar a day (6 teaspoon) it means 5 sugar cubes daily or 3 cookies or 1 chocolate eclair or 1/2 glass of soda or 40 gr of chocolate…  Looking after yourself starts with teaching your palate to love what is good for you, 20 gr it is 1/2 mango or 3 small apples or 2 bananas…

In Chinese medicine food energy will not be calculated in calories but in actual effect on the body as cold, cool, neutral, warm and hot. Those different energies will circulate in the body and act on our organs accordingly.

Just feel the effect of food on you and learn to eat the one that make you feel good.

Look after yourselves, eat well and be happy.

By Happy2feed




  1. Encyclopædia Britannica, inc.
  2. Byrd-Bredbenner, C., Moe, G., Beshgetoor, D., & Berning, J. R. (2013). Wardlaw’s perspectives in nutrition (Ninth edition /). New York, NY: McGraw-Hill.
  4. E HUSKISSON, S MAGGINI AND M RUF. (2007) The Role of Vitamins and Minerals in Energy Metabolism and Well-Being. The Journal of International Medical Research 2007; 35: 277 – 289. Basel, Switzerland
  5. Lodish H, Berk A, Zipursky SL, et al. Molecular Cell Biology. 4th edition. New York: W. H. Freeman; 2000. Section 16.2, Electron Transport and Oxidative Phosphorylation.
  8. Myhill, S., Booth, N. E., & McLaren-Howard, J. (2009). Chronic fatigue syndrome and mitochondrial dysfunction. International Journal of Clinical and Experimental Medicine, 2(1), 1–16.
  9. Berg JM, Tymoczko JL, Stryer L. Biochemistry. 5th edition. New York: W H Freeman; 2002. Section 30.2, Each Organ Has a Unique Metabolic Profile.
  10. Hofmann, S. M., & Havel, P. J. (2015). The good, the bad, and the unknown: Fructose and FGF21. Molecular Metabolism, 4(1), 1–2.
  11. Byrd-Bredbenner, C., Moe, G., Beshgetoor, D., & Berning, J. R. (2013). Wardlaw’s perspectives in nutrition (Ninth edition /). New York, NY: McGraw-Hill.
  12. Bilsborough S, Mann N. A review of issues of dietary protein intake in humans. Int J Sport Nutr Exerc Metab. 2006 Apr;16(2):129-52.
  13. Romain AJ, Carayol M, Desplan M, Fedou C, Ninot G, Mercier J, Avignon A, Brun JF. J Nutr Metab. 2012; 2012:285395. Epub 2012 Aug 14.
  14. Kreisler, R.B. Et al (2010). Issn exercise and sport nutrition review: research and recommendations. Journal of the international society of sports nutrition


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