The title of this article probably isn’t a direct representation of the content within it, however its message most certainly is. If losing fat was easy, we wouldn’t have an obesity epidemic. Better yet, in theory we would all be fit, healthy, happy and chasing down our goals on a daily basis.
The reality is far different. Fat loss takes change. Massive change!
It takes a change in attitude, a change in mindset and alongside both of those changes it takes a huge change in habits.
But therein lies the problem as well…
Losing fat or more specifically burning more calories than you consume in order to burn excess body fat, takes a conscious effort to essentially ‘starve’ your body long term in an effort to look and feel better.
Unfortunately… starving yourself, albeit it only slightly if we assume your diet is well balanced, creates a cascade of negative hormone changes, an increase in your senses of taste and smell in an effort to make you want to eat more and a simultaneous shut down of your internal motivation to move more.
I have spoken about NEAT before in my article about How Many Calories Do I Need? But today I’d like to take it that next step further and look at the research behind how NEAT changes during a fat loss phase.
NEAT is defined as Non Exercise Activity Thermogenesis, which is the amount of energy your body burns as a result of non-direct exercise.
For example, an individual who has a standing job in the retail industry, will have a much higher NEAT than an office desk worker who is sitting all day.
But here is the kicker…
During caloric restriction, spontaneous physical activity, which is a component of NEAT, becomes notably reduced (1). More specifically, it was found in the 80’s that caloric thermogenesis achieved via NEAT varied up to 800 calories per day in individuals subjected to a metabolic chamber (2). And even more concerning, not only does it become reduced during caloric restriction, but it has also been indicated that NEAT remained reduced even after subjects returned to freely eating in the post study phase as well (3).
So while you’re fighting to burn more, your body is fighting against you to burn less. Even worse, it still fights against you once you feed it enough, or in some instances, when you feed it too much as well.
Just think about that for a second.
We eat less and train more in an effort to enhance our attempts at maximising fat loss, yet subconsciously our bodies send out signals to slow us back down.
This is exactly what I meant above when I referred to the fact that caloric restriction for the benefit of physical appearance, physiologically, is in fact long term death due to starvation.
Our bodies will fight to survive!
Now if your curiosity is anything like my own, the question I guess that needs answering is why. Why does our body fight to hold onto the weight we are trying to shift, even if the weight we are trying to remove is deemed unhealthy?
I suppose the short answer is, survival.
Unfortunately we are still not 100% sure on what the specific compensatory changes are from an endocrine or neurological perspective that cause a reduction in NEAT, however, one may postulate that it is due to a cascade of hormonal changes with no one specific cause being blamed. In essence, we need to consider external factors such as exercise amount and food intake, alongside their coinciding internal responses to such a stimulus.
We understand that when we eat less, ghrelin rises, which is a hunger-inducing hormone. Similarly when we liberate fat from its stored cell, leptin signals the brain and tells our body to slow down its rate of thermogenesis as well.
Outside of internal factors, environmental factors come in to play as well when looking at the cultural expectations of the community and whether or not movement or exercise are encouraged or discouraged.
The point is… the effect on NEAT is multi dimensional and complex.
However, with physiology aside, we can still do something about it.
With our knowledge of NEAT, the expected increase in hunger, a reduction in satiety and our reduced caloric burn efficiency during exercise, the question that begs to be answered now is what do we do about it?
It’s easy...We move!
Remember, there is potential for a reduction in NEAT of up to 800kcal per day.
From a mathematical standpoint, burning 800 calories less per day is the same as consuming 89g of fat in your diet. It’s the same as burning 89g grams of fat from stored triglycerides as well.
Keep that up for 7 days and now you have potentially missed out on burning 620g of fat in a single week.
Never underestimate the power of movement.
So, next time you consider initiating a fat loss phase, don’t just think about the traditional methods to burn energy while consuming less, but instead think holistically.
Understand that your body is fighting to make you burn less, of which you will need to consciously attempt to burn more or at least burn the same amount of calories each week.
Instead of following the simplistic approach of training more and eating less, learn to simply move more and let your body do the work for you.
While fat loss may appear simple, if it were that easy we would all be successful.
Move more and stop doing less!
Trexler, E., Smith-Ryan, A. and Norton, L. (2014). Metabolic adaptation to weight loss: implications for the athlete. J Int Soc Sports Nutr, 11(1), p.7.
Ravussin, E., Lillioja, S., Anderson, T., Christin, L. and Bogardus, C. (1986). Determinants of 24-hour energy expenditure in man. Methods and results using a respiratory chamber. Journal of Clinical Investigation, 78(6), pp.1568-1578.
Weyer, C., et al. (2000). Energy metabolism after 2 years of energy restriction: the biosphere 2 experiment. The American Journal of Clinical Nutrition, 72(4). pp 946-953.
Novak, C. and Levine, J. (2007). Central Neural and Endocrine Mechanisms of Non-Exercise Activity Thermogenesis and Their Potential Impact on Obesity. Journal of Neuroendocrinology, 19(12), pp.923-940.