Making Sense of the Metabolism: Breaking Down the Basics of How Your Body Uses Food
I'm sure we've all heard it before: "my metabolism is just so fast, I can't gain weight!" And as much as you might not want to.... You can't help but roll your eyes. After all, why are some people so blessed with a fast metabolism? And what is metabolism, anyway?
Today, we're breaking down the basics of what metabolism is, what it does, and what it means for you!
What is metabolism?
Generally speaking, Metabolism is a phrase we use to refer to the set of chemical reactions in organisms that sustains life; it's much, much more complicated than you'd expect! Metabolism accounts for three integral processes in the body: the conversion of food to energy to run cellular processes, the elimination of metabolic wastes, and the conversion of food/fuel to building blocks for proteins, lipids, nucleic acids, and some carbohydrates. These metabolic reactions can be split into two groups: catabolic, the breaking down of compounds, and anabolic, the building-up of compounds. For today, though, you don't need to worry about that! Instead, just know that when someone (usually... unless you're in biology class!) refers to their metabolic rate, they're referring to how quickly their body processes food.
What does it mean when someone has a "fast metabolism"?
When someone has a "fast metabolism," that means that their body performs those chemical processes I mentioned in the last slide very quickly. When someone has a fast metabolism, it means their body performs these processes so fast that they need to consume more calories to use as fuel! That's why people with a fast metabolism can eat a greater amount of food and not gain fat; their bodies are using that extra food to fuel these biological processes. Meanwhile, those who have slower metabolic rates don't use up those extra calories, so they tend to store those excess calories as fat.
Categories of Metabolic Rate
Your metabolic rate is the number of calories you burn in a given amount of time or your calorie expenditure. There are several categories of metabolic rate that determine how many calories you burn, including...
Basal metabolic rate (BMR): Your BMR is the very minimum number of calories your body needs to consume to function at its most basic level.
Resting metabolic rate (RMR): The number of calories your body burns while at rest. Your RMR generally accounts for 50-70% of your total calorie expenditure, or how many calories you burn in a day.
Thermic effect of food (TEF): The number of calories burned while your body is digesting and processing food. TEF usually represents about 10% of your total energy expenditure.
Thermic effect of exercise (TEE): The calories you burn during exercise.
Non-exercise activity thermogenesis (NEAT): The number of calories required for activities other than exercise. This includes fidgeting, changing posture, standing, and walking around.
What determines your metabolic rate?
There are quite a few factors that contribute to your metabolic rate, which is why some people have such fast metabolisms! Some of these contributing factors include...
Muscle Mass
That's right! People who have more muscle tend to burn more calories daily than those with higher amounts of fat.
Body Size
This is kind of a no-brainer; the larger the body, the more calories the body needs to function!
Age
Yep, as you age, your metabolism tends to slow down. That's one of the reasons people tend to gain weight as they age.
Physical Activity Level
Again, no duh. The more you move and the more active you are, the more calories your body needs.
Hormone Disorders
Unfortunately, there are several hormone disorders that can drastically affect your metabolic rate; hypothyroidism and Cushing's Syndrome are two disorders that can slow your metabolic rate and make you prone to weight gain.
How can we speed up our metabolism?
Number One: Get Moving!
Sure, your activity energy expenditure might only make up 30-40% of your total energy expenditure, but that can still have a huge effect on your total caloric burn! Also, moving more doesn't just mean working out more; it means moving more in GENERAL. That means...
Fidgeting more!
Walking around regularly!
Standing while working!
Parking further away so you have to walk more!
These little changes will increase your NEAT, which makes up anywhere from 10-20% of your total expenditure.
Number Two: Learn to LOVE HIIT workouts!
Ah, good old HIIT; there's a reason we love high-intensity interval training around here! HIIT is basically when exercise involves very high-intensity bouts of activity followed by periods of rest; and when I say rest, I mean REST! The benefits of HIIT are only gained when you actually rest. HIIT significantly speeds up your metabolism, especially in the hours following the workout; this effect is known as the HIIT afterburn! An example of a HIIT workout could be running sprints on the treadmill; you can sprint for one minute, rest for 30 seconds, and continue on for roughly ten minutes or so.
Number Three: Start Strength-Training!
This might be the biggest key to improving your metabolism: start lifting and lifting HEAVY. Not only does strength training increase your active energy expenditure, it also can help you increase muscle mass, which increases your RMR! Increased muscle mass SIGNIFICANTLY increases the number of calories you burn at rest. Also, remember how I said increasing age can lead to decreased metabolic rate? Studies have shown that strength training can help counteract this effect! One study showed that doing strength exercises for 11 minutes a day, three times per week, resulted in an average increase of 7.4% in resting metabolic rate after half a year — and an additional 125 calories burned per day. Only ELEVEN MINUTES PER DAY DID THAT. So yeah, strength training is key when it comes to increasing your metabolic rate!
Number Four: Start Sleeping MORE.
If it isn't clear by now, sleep is a HUGE part of your overall health, including your metabolism. One study showed that metabolic rate decreased by 2.6% when healthy adults slept for only four hours per night for five days in a row... Imagine what not sleeping enough for YEARS will do to your metabolism! Another five-week study determined that sustained sleep disruption reduced resting metabolic rate by 8%! If there is one thing I beg of you, it's to make sleep a priority. You should be sleeping at LEAST seven hours per night, no matter what; this is the most basic thing you can do to improve your health and keep your metabolism running as it should.
Number Five: Eat More Protein!
We're big on eating protein around here; have you noticed? Yep, protein is a huge part of your metabolic rate. All foods lead to a temporary increase in metabolic rate, known as the thermic effect of food (TEF), but this effect is much stronger after eating protein compared to carbs or fat! Protein can actually increase your metabolic rate (for a short period after eating) by 20-30%, compared to only a 3-10% increase with fat and carbs. Eating high amounts of protein can also help counteract the loss of muscle mass and metabolic rate associated with weight loss!
All in all...
Sure, it can be frustrating when your friends (or your husband/partner) all seem to have much faster metabolisms than you, but never fear: Simple changes you make daily can improve your metabolism, too! Remember, though, if you want to lose weight, you need to be focusing on lowering your caloric intake as a whole. You can't just focus on increasing your RMR and hope for the best! Remember, Athena Fit fam, our bodies are pretty dang smart, and they know how to adjust to our choices. Love your body, and your body will love you right back!