Is my metabolism the reason I'm not losing weight?
In recent times, the idea of the metabolism being the cause of weight gain or weight loss plateaus is becoming more and more popular. Before we delve into that more, let's look at what the metabolism actually is.
Metabolism is defined as "the physical and chemical processes that occur in the body which keep us functioning normally in order to stay alive, such as breathing, blood circulation and nerve function".
What affects the metabolism?
The sum of the energy expenditure is called your total daily energy expenditure (TDEE), and that is the sum of three components: resting metabolic rate, thermic effect of food, and active energy expenditure.
1. . Resting metabolic rate (RMR).
As stated above, metabolism is the physical and chemical
processes that occur to keep us alive. Your resting metabolic rate
refers to the energy demand put upon the body to simply stay alive.
The RMR is accounting for approximately 70% of the TDEE of
What about people with fast metabolisms? There are in fact people with fast metabolisms who do have a metabolic advantage; however, it isn't as overwhelming as you would think.
96% of people stay within a 200-300 calories of the average RMR.
Your RMR is determined mostly by your fat free mass (FFM). Your FFM is made up of things like: skeletal muscle, organs, and bones.
Has my RMR slowed down? When people slash their calories drastically to lose weight very fast, they run the risk of slowing down their RMR below its "natural" level.
In addition to the potential for your RMR to slow down through drastic calorie reduction, your RMR can also slow as you age, since the older you get, the less FFM you have and the fewer energy generating cells you have.
2. Thermic Effect of Food (TEF)
The thermic effect of food (TEF) refers to the energy required
to digest, absorb, and store nutrients, and this accounts for
approx. 10% of your total daily energy requirements (TDEE).
Of the three main macronutrients, they all have different thermic rates:
- Carbohydrates: 5-10%
- Fats: 0-3%
- Protein: 20-30%
As you can see protein burns by far the most energy of all of
the macronutrients. For that reason, and because of its protection
against muscle breakdown, protein plays a vital role in the weight
Note: We are not now saying eat all the protein in the world because it burns the most calories. The energy that would go towards digestion of protein is just 20-30% of the 10% TEF. This is less than 100 calories per day.
3. Activity Energy Expenditure (AEE)
The activity energy expenditure (AEE) has the biggest variables
ranging from 15% (with the sedentary individuals) to 50% (in highly
active individuals). AEE comprises of both physical activity (PA)
and spontaneous physical activity (SPA), you may have heard of
this before as non-exercise activity thermogenesis.
PA involves weights training, and cardiovascular training, whereas SPA covers minor subconscious acts of daily life, such as fidgeting, chewing, walking short distances, or even maintaining one's posture. Studies have shown that SPA accounts for 4-17% of the TDEE, or approx. 100-700 calories per day.
Note: When you are consistently eating less, and energy demands are increase through PA, a subconscious adaption of SPA is decreased. You may have felt this in the final weeks of a Weight Loss Challenge yourself - You may have felt lethargic, tired, less fidgety, and want to sleep more. This is your body's adaption to weight loss through decreasing your SPA. You can manage this keeping an eye on your daily steps per day and keeping it consistent.
Can you overcome a slow metabolism?
As we have seen above, there are many ways in which your
metabolism can slow down. When you begin a weight loss program, it
is inevitable that your metabolism will slow down. Making sure that
your plan and stick to a smart amount of weight being lost each
week to prolong the rapid decrease in metabolism seen in drastic
Once you've lost your weight - what now?
Now is the time where most people struggle. You need to tackle nutrition with the same discipline of weight loss; however, you will be seeing a weight GAIN on the scale. This weight gain is good. The weight gain will come from an increase in food storage, not fat. Once you have lost the weight you want to lose, you need to change your program goal to either muscle gain, or body-fat maintenance. These changes will see a change in macro's (and calories).
If you always eat to lose weight, your metabolism will always be slower than it could be.
If you change your goal when you hit your weight loss goal, you will adapt to a surplus in food, your metabolism will adapt, and you will overcome your slow metabolism.
*Disclaimer: Individual results vary based on agreed goals. Click here for details.