Metabolic Adaptation


Metabolic Adaptation

Dr. Layne Norton is primarily responsible for the recent surge in the interest of Metabolic Adaptation, a physiological adaptation that occurs in response to the input you are giving your body – through diet/exercise/ect.

If you ever plan on losing fat and then maintaining the physique you worked so hard to obtain, read on!

What is Metabolic Adaptation?

When undergoing an extreme calorie restricted diet, especially when coupled with extensive cardiovascular activity, the body undergoes certain adaptations that make it progressively harder and harder to lose fat. These adaptations, “Metabolic adaptation,” prime the body for fat regain/rebound.

A list of a few physiological changes that occur that make Metabolic Adaptation the enemy:

1. Exercised induced thermogenesis – DECREASES = you are burning less and less calories as you workout

2. Thermic effect of food decreases, meaning the energy it takes to simply digest your food decreases (i.e. the digestive tract becomes more efficient at extracting every bit of calories it can to use/store)

3. NEIT – Non Exercise Induced Thermogenesis DECREASES – you aren’t burning as many calories when you are watching TV/sleeping – personally, my favorite time to burn fat.

4. Fat Oxidation DECREASES

5. Systemic change in gene expression profile – Fat storage gene expression INCREASES (your DNA starts expressing genes that facilitate fat storage – this is systemic (whole-body) and literally effects EVERY cell in the body)

6. Intestinal Bacteria Flora (Ecosystem balance shift) changes favoring bacteria with a more efficient fermentation process to again extract every ounce of energy from food

7. Liver – DECREASE protein synthesis (decrease thermogenesis) INCREASE in making fat from glucose

8. Decrease O2 consumption (decrease BMR)

The Rebound

Adaptations created through long term large caloric deficit results in slow “re-gaining” of these more favorable adaptations. (i.e. anything besides a SLOW increase in calories and SLOW decline in exercise – will result in substantial fat gain without the associated benefits that come with a “re-feed”)

If you increase calories too quickly/decrease cardio too quickly:

-Large increases in fat deposition
-Satiety still low (so your stomach will be full, but you’ll still be starving)
-Adipose cell hyperplasia (fat cells increase in number) i.e. fat cells create baby clones of themselves increasing body’s fat storing potential
-Still have efficient energy useage – so everything you are eating is being stored like crazy


-Slowly increase your LBM (lean body mass) and slowly “undo” or better yet “re-adapt” to create a physiological environment that does not efficiently use energy and facilitates fat dissipation and muscle protein synthesis as well as the intestinal gut bacteria to stop being so damn efficient at using every calorie.

-Avoid the extremes (either way – fat loss or muscle building). On the quest to building the physique you want long term, there is really only one way to get there. Basically, make SLOW, consistent, never ending improvements.

-To lose fat, make the smallest change possible that has you losing fat. “Don’t back yourself into a corner”

-To gain muscle, the same applies. The old school “bulking” method is dumb. You want to eat the smallest increases over baseline to stimulate growth (of course, coupled with a strategically integrated exercise program).

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