This word “metabolism” is thrown around a lot these days. You know that if yours is too slow you might gain weight. There is a lot more to your metabolism than exercising or eating all the time. Are these even healthy things to do? How is this possible, what exactly does this all mean?
Well technically “metabolism” is the word to describe all of the biochemical reactions in your body. It's how you take in nutrients and oxygen and use them to fuel everything you do. Your body has an incredible ability to grow, heal, and generally stay alive and, without this amazing biochemistry, you would not be possible. Your body gets the energy to do these things by metabolising the food you eat.
Metabolism includes how the cells in your body:
So when you put all of these processes together into your metabolism you can imagine that these processes can work too quickly, too slowly, or just right. Which brings us to the “metabolic rate.” This is how fast your metabolism works and is measured in calories (yup, those calories!) The calories you eat can go to one of three places:
As you can imagine the more calories you burn as work or creating heat the easier it is to lose weight and keep it off because there will be fewer “leftover” calories to store for later.
There are a couple of different ways to measure metabolic rate. One is the “resting metabolic rate” (RMR) which is how much energy your body uses when you're not being physically active. The other is the “total daily energy expenditure” (TDEE) which measures both the resting metabolic rate as well as the energy used for “work” (e.g. exercise) throughout a 24-hour period.
What affects your metabolic rate? In a nutshell: a lot!
The first thing you may think of is your thyroid. This gland at the front of your throat releases hormones to tell your body to “speed up” your metabolism. Of course, the more thyroid hormone there is the faster things will work and the more calories you'll burn. That's not the only thing that affects your metabolic rate!
How big you are counts too! Larger people have higher metabolic rates; but your body composition is crucial! As you can imagine, muscles that actively move and do work need more energy than fat does. So, the more lean muscle mass you have, the more energy your body will burn and the higher your metabolic rate will be. Even when you're not working out.
This is exactly why weight training is often recommended as a part of a weight loss program. Because you want muscles to be burning those calories for you. The thing is, when people lose weight their metabolic rate often slows down which you don't want to happen. So you definitely want to offset that with more muscle mass.
Aerobic exercise also temporarily increases your metabolic rate. Your muscles are burning fuel to move so they're doing “work”.
You can use it to your advantage when you understand how your body metabolizes foods differently.
What about calories?
We use calories as a way of measuring energy in food. A calorie is used in science for the amount of energy needed to raise the temperature of water by one degree. We can lose weight when we spending more energy than we consume in calories. I want to explain why losing weight is not just about calories in and out. Calories are a method of of tracking your diet, but it's not the only thing you should worry about and it's not the only goal. I am going to use my favorite example to explain what happens when we go on low calorie diet.
Calories are energy. When you restrict your calories, your body is thinking that there is a deficit of energy and starts slowing your metabolism: the rate in which you make energy out of food, basically. It's like when your paycheck was $2000 and you were spending $2000. So all of a sudden your boss cuts it to $1500, and what would you do in this case? Continue spending every month and eventually go broke, or cut your expenses by $500?
Your body realises that you’re only getting 1,500 calories a day and slows down. While you’re restricting calories you will probably lose weigh at first. This weight loss only happens because your body doesn’t realise yet that you’re getting 1,500 insted of 2,000 calories. So it just continues to burn its normal amount and you lose weight. What happens next? Yes, your metabolism begins to adjust. Your body begins to slow down.
You’re cutting calories and exercising more but your weight is staying the same. Plus you’re starving to death because you dont get nutrients since your cells are not sensitive to insulin and shut down. Your insulin is still high from eating the wrong foods, your hormones are out of whack and you have insulin and leptin resistance.
Remember weight gain is just a symptom! Heal your hormones and fat will start melting!
The type of food you eat also affects your metabolic rate!
Your body actually burns calories to absorb, digest, and metabolize your food. This is called the “thermic effect of food” (TEF). Fats, for example, increase your TEF by 0-3%; carbs increase it by 5-10%, and protein increases it by 15-30%. By trading some of your fat or carbs for lean protein you can slightly increase your metabolic rate.
Another bonus of protein is that your muscles need it to grow. By working them out and feeding them what they need they will help you to lose weight and keep it off.
Although when you starting lose weight its good to remember that you need less calories since you are smaller, right? As you become a smaller person, it takes less energy to support your body. And don't forget the mind-body connection. There is plenty of research that shows the influence that things like stress and sleep have on the metabolic rate.
This is just the tip of the iceberg when it comes to metabolism and how so many different things can work to increase (or decrease) your metabolic rate.
Lean Protein Lemon Herb Roasted Chicken Breasts Recipe
Tip: You can add a leftover sliced chicken breast to your salad for lunch the next day!