Metabolism. You may know that if yours is too slow you might gain weight. But what exactly does this all mean?
Your body is comprised of a series of biochemical reactions. It is an amazing machine that takes in nutrients and oxygen and uses them to fuel everything you do. The word “metabolism” actually describes all those biochemical reactions that an organism, in this case, you, need to live. It’s three main purposes are to: help convert fuel for use in cellular processes, provide building blocks for cell growth and healing, and for elimination processes.
Metabolism includes how the cells in your body:
-Allow activities you can control (e.g. physical activity etc.).
-Allow activities you can’t control (e.g. heartbeat, wound healing, processing of nutrients & toxins, etc.).
-Allow storage of excess energy for later.
When you put all of these processes together to form your metabolism, sometimes they can work too quickly, too slowly, or (ideally) just right.
Which brings us to the “metabolic rate.”
This is how fast your metabolism works and is measured in kilocalories, or more commonly abbreviated to just “calories.”
The calories you eat can go to one of three places:
-Fuel physical activity (i.e. work, exercise, and other activities).
-Fuel for biochemical reactions in your body to exist.
-Storage (i.e. extra leftover “unburned” calories stored as fat).
As you can imagine, the more calories you burn as fuel for activities or biochemical processes, 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 many calories your body needs just to perform the basic functions to live like your heartbeat, moving your blood through your body, fueling your lungs to breath. Imagine what your body needs to function while you lie in bed without any physical activity; this is your RMR.
Now imagine you get up, go to work, hit an exercise class and later return to bed. Just like a car, your body needed more fuel for those activities. This is where the other energy expenditure measurement comes in. The “total daily energy expenditure” (TDEE) includes both the resting metabolic rate (RMR) or what you need to just exist AND includes the calories you need to actually function, work or exercise over the course of a 24-hour period.
What affects your metabolic rate?
More than you can imagine!
Age, gender, and body size all play a role. But it isn’t just about size, what is also crucial is body composition.
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.
Sometimes 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.
Speaking of exercise, physical activity is also important.
Aerobic exercise also temporarily increases your metabolic rate. Your muscles are burning fuel to move so they’re doing “work.”
When people have a hard time losing weight, sometimes they will wonder if their thyroid is operating properly. The thyroid gland is located at the front of your throat and 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. If the thyroid is not producing enough hormones, your metabolism will be impacted. This is a great example of how a hormonal imbalance can impact metabolism.
Other factors which can impact your metabolism might include genetics; environmental changes such as heat or cold variances; certain medications and even dietary intake.
Yes, 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).
You can use it to your advantage when you understand how your body metabolizes foods differently.
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. However, be mindful. This is not an excuse to eat only proteins. Too much protein can actually be tough on your kidneys.
Last, but not least, don’t forget the mind-body connection. There is plenty of research that shows stress and sleep have an influence as well.
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.
Recipe (Lean Protein): Lemon Herb Roasted Chicken Breast
2 lemons, sliced
1 tablespoon rosemary
1 tablespoon thyme
2 cloves garlic, thinly sliced
4 chicken breasts (boneless, skinless)
dash salt & pepper
1 tablespoon extra virgin olive old
Preheat oven to 425F. Layer ½ of the lemon slices on the bottom of a baking dish. Sprinkle with ½ of the herbs and ½ of the sliced garlic.
Place the chicken breasts on top and sprinkle salt & pepper. Place remaining lemon, herbs, and garlic on top of the chicken. Drizzle with olive oil. Cover with a lid or foil.
Bake for 45 minutes until chicken is cooked through. If you want the chicken to be a bit more roasted, then remove the lid/foil and broil for another few minutes (watching carefully not to burn it).
Serve & enjoy!
Tip: You can add a leftover sliced chicken breast to your salad for lunch the next day!