Metabolic Adaption: A Lesson from the Biggest Loser

Fat loss is simple.
 

It’s not a mystery and there’s no magic involved.


Seriously. Science has repeatedly shown that when we establish a calorie deficit for a period of time weight loss occurs.

We can either eat less, move more or a combination of both.

This is seen in the popular reality TV show the Biggest Loser, where obese contestants are placed in the ‘perfect’ weight-loss environment and lose massive amounts of weight due to the huge calorie deficit the contestants are subject to.

Recently a study came out by Hall showing that the majority of contestants had regained the lost weight and some now weighed more. This started an avalanche of articles, some which painted a grim picture for those looking to lose weight and keep it off.
 
And therein lies the problem

Maintaining the weight lost or knowing what to do if weight loss stalls before you’ve reached your target.
 
If you’ve ever dieted before you’ve probably experienced the point where your weight loss slows down to a crawl or even completely stops.
 
You’re left scratching you’re head thinking ‘what now?’

Stalling is actually completely normal and makes a lot of sense from an evolutionary perspective.

We can trace this back to our caveman brethren. Prior to the agricultural revolution (when crops and farming became widespread) the possibility of starvation was legit! If you didn’t hunt or gather your food then you weren’t eating. Plain and simple.

On the other hand, the chances of becoming fat and overweight was almost unheard of.

Let’s face it, if you’re a fat caveman or woman, your easy sabre tooth fodder.

Our bodies evolved to defend against starvation. While a life saver at the time, in todays society this adaption process is now making it incredibly easy to gain weight and increasingly difficult to maintain losses because our body sees it as a threat to survival.  

Often this can lead us to think “What the hell body, You don’t even get me!”

And it’s true, our almighty brain doesn’t get the why.

It doesn’t understand you’re dream of dancing on a trailer in front of sorority girls aka Zac Efron in Bad Neighbors 2. 

It just senses the current energy (food intake and body fat) situation going on in the body and adjusts accordingly.

But let’s rewind.

 
You start a new diet. Whether it’s to reduce body fat, look great naked, improve health, improve sports performance, defeat Zac in a dance off, whatever…
 
You’re smart (you read great content), you’re aware that body composition is primarily regulated by calorie balance and therefore you ensure that you place yourself in an energy deficit through either eating less calories, increasing energy expenditure or a combination of the two.
 
And things are going awesome. Your maintaining strength, you’re seeing the scale number/measurements decrease and peeps in the gym are complimenting your new found definition.

“This dieting hoo ha isn’t that bad! What’s everyone complaining about?” you think to yourself.

Then it starts to slow. What use to be a half a kilo a week is now less than .2 kilograms.

And then you stop losing weight.
 
Sound familiar?

What happened and more importantly what do I do??!!

 There are a number of possible scenarios that can lead to a stall in weight loss.

1)    Your energy intake through food has slowly crept up to decrease the calorie deficit originally created.

2)    Water retention is masking true fat loss. (A topic for another article)

And the focus of this article:


3. Your body caught up. 

 This is called metabolic adaption or adaptive thermogenesis.[1]
 
Let me explain.

Beginning your diet, energy intake decreases, your body starts to break down and utilize more stored fats for fuel. Your body notices and starts to put in place safety measures thinking you’re literally heading towards starvation.
These processes slowly work to close the calorie deficit you created at the beginning of your diet.
 
These adaptations  include:

  • Increased mitochondrial efficiency (less calories burned to produce the same amount of ATP)[2]

  • Decreased energy expenditure (metabolic rate)

  • Elevations in hormones that increase catabolism (muscle breakdown) and hunger [3]

  • Decreased hormones that promote anabolism (muscle building), energy expenditure, and satiety [3]

In addition to this we must remember that as you lose weight, you’re becoming smaller, meaning you’re not using as much energy moving around because you have less active tissue burning fuel.

 Changes in mitochondrial (your cells power plants) efficiency and energy expenditure decrease your energy deficit, which slows weight loss.
 Hormonal changes make it difficult to maintain your hard earned muscle, make you feel lethargic and can increase the amount of time you feel hangry!
 
Sounds horrible right?
 
But wait there’s more!
 
These adaptations also extend beyond the weight loss phase.
 
 Let’s say you made it down to that lean look you were shooting for, or you’ve achieved a stage-ready level of body fat.
 
Even after you’ve lost the weight, research has indicated that many of these adaptations persist as you try to maintain your new body weight and can set you up for a rebound. [4]

It appears this is what happened with the Biggest Loser contestants in the study above to quite a large extent.

“Should I even try to lose body fat then? It seems like a horrible, impossible task!”.
 
Yes, you should (if that’s your goal). And no it’s not. Not unless you make it that way…

What can we do to reduce these negative adaptions?
 

While we can’t completely eliminate these adaptions, through proper, smart nutrition and training we can likely minimize them and make the process easier.
 

1) Consume sufficient protein.

 

When dieting, especially as you get leaner, protein becomes more and more important. [4,5]
It has the highest thermic effect of all the macronutrients (it uses the most energy to digest and absorb) and is the most filling! Both of these are big positives when we are trying to lose fat.

But the main reason a higher protein consumption is required is because it will help retain lean body mass! And the more muscle we can retain the higher our metabolism will be.
 


2) Perform a well structured, progressive resistance training program.


 If there is one thing that’s more important for muscle retention when dieting then protein, it’s maintaining weight on the bar when training.

We need to be letting the muscle know “Hey buddy, I know you’re not getting as much lovin' but your still needed”.

When the body is in an energy deficit it will be using stored fuel sources. Preferably the majority of this will be fat but the leaner you get the more your bodies inner Hannibal emerges (aka the more amino acids it uses for fuel).[6]


 
3) Start with the smallest deficit required to achieve your goal rate of weight loss.
 

It would appear that the amount of resistance your body provides may also be related to the size of the energy deficit created. [7]

So a large male dropping food to 1200 calories signifies to the body an urgent energy crisis, “all hands on deck, we’re slowing this fat loss ship down”.

 Biggest Loser anyone?
 
For this reason it’s a good idea to go in the opposite direction and choose a moderate to slow rate of weight loss and when weight loss stalls occur make conservative adjustments to re-create the deficit.
 
This also makes sense from a habit forming and sustainability perspective. The faster and more drastic the changes you make, the more likely they are to be unsustainable.


 
4) Keep cardio to the minimum necessary.


 Unfortunately, (unless you dig cardio) the majority of us are going to need to incorporate cardio at some point in order to get to our target body fat.
 
Not only can cardio potentially cut into your recovery from resistance training (especially too much HIIT), but the interference effect of concurrent training may be counterproductive. [9]

When cardio is necessary, it may be best to avoid higher-impact, long durations, and moderate intensities. Read more about cardio during weight loss here. 


5) Consider taking a diet break
 

If you have a lot of weight to lose or have been dieting for a prolonged period of time (over 12 weeks), it may be worth implementing a diet break.
 
A diet break is exactly how it sounds.

A planned week where you bump up your calories to (your new) maintenance levels. This can allow both a mental reprieve and allow some of the negative hormonal adaptions to move back towards baseline. [10]
 
Expect to gain a little bit of weight over the week but rest easy knowing that this break will help you in the long run.
 

Wrapping it up

Essentially, the Biggest Loser is an extreme short-term approach to weight-loss that results in an extreme response by the body. By employing the above strategies you can lose the weight more effectively, increase the chances of maintaining fat loss, and set yourself up for improved body composition and performance down the road!

 

References:

1.    Rosenbaum M, Leibel RL: Adaptive thermogenesis in humans. Int J Obes 2010, 34(Suppl 1):S47–S55.

2.    Trexler et al.: Metabolic adaptation to weight loss: implications for the athlete. Journal of the International Society of Sports Nutrition 2014 11:7.

3.    Rossow LM, Fukuda DH, Fahs CA, Loenneke JP, Stout JR: Natural bodybuilding competition preparation and recovery: a 12-month case study. Int J Sports Physiol Perform 2013, 8:582–592.

4.    Helms ER, Zinn C, Rowlands DS, Brown SR. A systematic review of dietary protein during caloric restriction in resistance trained lean athletes: a case for higher intakes. Int J Sport Nutr Exerc Metab. 2013;24:127-38.

5.    Paddon-Jones D, Westman E, Mattes RD, Wolfe RR, Astrup A, Westerterp-Plantenga M: Protein, weight management, and satiety. Am J Clin Nutr 2008, 87:1558S–1561S.

6.    Pasiakos SM, Margolis LM, Orr JS. Optimized dietary strategies to protect skeletal muscle mass during periods of unavoidable energy deficit. The FASEB Journal. 2015 Apr 1;29(4):1136-42.

7.    Trexler ET, Smith-Ryan AE, and Norton LE. Metabolic adaptation to weight loss: implications for the athlete. Journal of the International Society of Sports Nutrition 11: 7, 2014.

8.    Rosenbaum M, Hirsch J, Gallagher DA, Leibel RL: Long-term persistence of adaptive thermogenesis in subjects who have maintained a reduced body weight. Am J Clin Nutr 2008, 88:906–912

9.    Wilson JM, Marin PJ, Rhea MR, Wilson SM, Loenneke JP, Anderson JC. Concurrent training: a meta-analysis examining interference of aerobic and resistance exercises. The Journal of Strength & Conditioning Research. 2012 Aug 1;26(8):2293-307.

10. Levine, JA, NL Eberhardt, and MD Jensen, Role of Nonexercise Activity Thermogenesis in Resistance to Fat Gain in Humans. Science, 1999 283(5399): p 212-214