Harnessing the Power of Energy Metabolism in Weight Loss – The Path to a Successful Journey!


Does your scale refuse to budge despite counting calories like a hawk, sweating it out at the gym daily, and adhering religiously to a clean diet? If so, don't despair or blame yourself! It's high time we unravel the veiled mastermind behind the weight loss saga - energy metabolism!

Delving into the Complexities of Energy Metabolism

Our body operates like sophisticated machinery, where weight loss extends beyond the simplistic paradigm of 'calories in versus calories out.' It encompasses a labyrinthine interaction between diet, energy expenditure, and our body's metabolic adjustments (Trexler et al., 2014). Pioneering research reveals that weight loss and energy deficiency compel our body to recalibrate its metabolic functions.

In an extensive energy deficit phase, the equilibrium of hormones and energy metabolism shifts, curtailing our energy expenditure and satiety (Trexler et al., 2014). It's both intriguing and daunting to discover that energy expenditure varies tremendously between individuals. A groundbreaking study by Pontzer et al. (2021) unveils such disparity - an 80 kg individual might expend a mere 1400 kcal, whereas another of the same weight could expend an astounding 5700 kcal per day.

Adaptive Thermogenesis: The Body's Superhero Mechanism

During phases of energy deprivation, our body kicks into survival mode, launching a defensive strategy to conserve energy. Merely two weeks of energy deprivation can trigger a slowdown in energy metabolism, a decrease in thyroid and sex hormone secretion, and a decline in unconscious physical activities termed as NEAT (Non-Exercise Activity Thermogenesis) (Strauss et al. 1985; Friedl et al. 2000; Duocet et al. 2001; Johannsen et al. 2012; Rossow et al. 2013; Knuth et al. 2014). This superhero mechanism, known as adaptive thermogenesis, plays a pivotal role in our total energy expenditure and, paradoxically, can hinder our weight loss endeavors (Doucet et al. 2001; Trexler et al. 2014; Müller et al. 2015).

Research further unveils that energy expenditure during exercise can decrease in an energy deficit state. Astonishingly, the same exercise could expend 10-20% less energy than before (Doucet et al. 2001; Bravata et al. 2007; Hill et al. 2009; Trexler et al. 2014; Müller et al. 2015). According to recent findings by Isola et al. (2023), energy expenditure in fitness athletes during competition preparation dwindles on average by 200 kcal in women and 300 kcal in men. In certain individuals, this reduction reaches up to an additional 350 kcal and 500 kcal beyond what would be predicted from the loss of body weight and corresponding changes in fat mass or lean mass alone (Rosenbaum et al. 2008).

The Quintessential Role of Personal Trainers and Coaches

Armed with this scientific knowledge, it becomes evident why traditional weight loss strategies often crumble, leading to disillusionment and motivation loss. Herein lies the invaluable role of a well-informed personal trainer or coach. Comprehending these physiological intricacies is paramount in devising a triumphant weight loss regimen for their clients. They are geared to navigate these metabolic transitions and tweak the plan in line with the individual's metabolic responses, thus transforming the weight loss journey from a body warfare into a harmonious symbiosis.

Acquire the Power of Knowledge with the IFBB Nordic Academy

Are you a personal trainer or coach eager to arm yourself with this revolutionary knowledge? Or are you someone grappling with weight loss and desiring to decode the science behind it? We have splendid news for you! The IFBB Nordic Academy is launching a Personal Trainer course this September.

This course aims to empower you with an all-encompassing understanding of energy metabolism and its instrumental role in weight loss. It paves the way for learning how to customize diet and exercise plans, accounting for individual metabolic variances and adaptive responses. Here is your golden opportunity to equip yourself with the tools to guide yourself and others on a victorious and sustainable weight loss journey. Sign up today and stay a step ahead in the weight loss marathon!

Remember, knowledge is power, and in this context, it could be the power to transform lives!

"Your body can stand almost anything. It's your mind that you have to convince." - Unknown.


Trexler, E. T., Smith-Ryan, A. E., & Norton, L. E. (2014). Metabolic adaptation to weight loss: implications for the athlete. Journal of the International Society of Sports Nutrition, 11(1), 7.

Pontzer, H., Yamada, Y., Sagayama, H., Ainslie, P. N., Andersen, L. F., Anderson, L. J., ... & IAEA DLW Database Consortium §. (2021). Daily energy expenditure through the human life course. Science, 373(6556), 808-812.

Strauss, R. Lanese, R & Malarkey, W. 1985. Weight Loss in Amateur Wrestlers and Its Effect on Serum Testosterone Levels. JAMA 254 (23), 3337–3338.

Friedl, K., Moore, R., Hoyt, R., Marchitelli, L., Martinez-Lopez, L. & Askew, E. 2000. Endocrine markers of semistarvation in healthy lean men in a multistressor environment. The Journal of Applied Physiology 88 (5), 1820–30.

Doucet, E. St-Pierre, S. Alméras, N. Després, J. Bourchard, C & Tremblay A. 2001. Evidence for the existence of adaptive thermogenesis during weight loss. The British Journal of Nutrition 85(6), 715-723.

Johannsen, D., Knuth, N., Huizenga, R., Rood, J., Ravussin, E. & Hall, K. 2012. Metabolic slowing with massive weight loss despite preservation of fat-free mass. The Journal of Clinical Endorinology and Metabolism 97 (7), 2489–2496.

Rossow, L., Fukuda, D., Fahs, C., Loenneke, J. & Stout, J. 2013. Natural Bodybuilding Competition Preparation and Recovery: A 12-Month Case Study. International Journal of Sports Physiology and Performance 8 (5), 582–592.

Knuth, N., Johannsen, D., Tamboli, R., Marks-Shulman, P., Huizenga, R., Chen, K., Abumrad, N., Ravussin, E. & Hall, K. 2014. Metabolic adaptation following massive weight loss is related to the degree of energy imbalance and changes in circulating leptin. Obesity (Silver Spring) 22 (12), 2563–2569.

Bravata, D., Smith-Spangler, C., Sundaram, V., Gienger, A., Lin, N., Lewis, R., Stave, C., Olkin, I. & Sirard, J. 2007. Using pedometers to increase physical activity and improve health: a systematic review. JAMA 298 (19), 2296–304.

Hill, J., Peters, J. & Wyatt, H. 2009. Using the Energy Gap to Address Obesity: A Commentary. Journal of the American Dietetic Association 109 (11), 1848–1853.

Müller, M., Enderle, J., Pourhassan, M., Braun, W., Eggeling, B., Lagerpusch, M., Glüer, C-C., Kehayias, J., Kiosz, D. & Bosy-Westphal, A. 2015. Metabolic adaptation to caloric restriction and subsequent refeeding: the Minnesota Starvation Experiment revisited. The American Journal of Clinical Nutrition 102 (4), 807–819.

Isola, V., Hulmi, J. J., Petäjä, P., Helms, E. R., Karppinen, J. E., & Ahtiainen, J. P. (2023). Weight loss induces changes in adaptive thermogenesis in female and male physique athletes. Applied Physiology, Nutrition, and Metabolism, (ja).