Metabolism is a word thrown around quite often when it comes to diet and exercise. You no doubt have heard metabolism myths, and may even have a vague idea of what it is. There are a few metabolism myths related to health and caloric expenditure we’d like to address.
In simple terms, metabolism is the process by which our bodies convert what we eat into the energy we need to survive and function. It is the energy output of your body that is going head-to-head with the energy input (calories in). Metabolism is in effect when you’re resting or sleeping, and takes energy to convert the food and nutrients you consume into the energy. The law of conservation states “Energy cannot be created or destroyed, energy can only be transferred or changed from one form to another.”
Metabolism encompasses five different categories of energy expenditure:
- Resting Metabolic Rate (RMR) – More than 60% of our energy is required for all of the basic functions that keep us alive. We burn calories while breathing, thinking, pumping blood, etc., simply as a natural process of life.
- Thermic Effect of Food (TEF) – About 10% of our energy is required to eat, digest and process the food we eat.
- Physical Activity (PA) – We all know exercise burns calories, so this one should be no surprise!
- Excess Post-Exercise Oxygen Consumption (EPOC) – This refers to the process our body undergoes after exercise. We continue to burn calories in order to return itself to pre-exercise levels.
- Non-Exercise Activity Thermogenesis (NEAT) – This is somewhere between RMR and PA. It is essentially any movement performed that is not considered exercise, i.e. standing, fidgeting, reaching, etc.
To sum it all up, ENERGY OUT = RMR + TEF + PA + EPOC + NEAT
Whew, glad that’s out of the way. Now that we’ve broken down how metabolism works (no pun intended), let’s focus on debunking some famous misleading myths.
MYTH #1: Skinnier individuals have a higher metabolism.
THE TRUTH: Metabolism actually has quite a bit to do with body size, but not in the way many may think. According to Dr. Yoni Freedhoff, Asst. Professor at the University of Ottawa, “skinny individuals almost invariably have slower resting metabolisms; there is literally less of them to burn while at rest.” He is referring to what is called a resting metabolic rate. We aren’t necessarily referring to body size being important but more body composition. We can boost metabolism by increasing lean muscle mass. Muscle burns more calories per hour than fat, which means that someone with a lean, muscular body needs more calories at rest to function than a person of the same size with a higher percentage of body fat.
Strength training is important for losing fat and keeping your body strong and healthy. In fact, maintaining your muscle mass as well as gaining more lean tissue is often what keeps people from gaining weight as they get older. That’s just one of strength training’s many powerful benefits.
Here’s are benefits of strength training and adding lean dense muscle mass:
- Burns extra calories for hours after your workout—what’s known as afterburn. This is especially true with high-intensity strength training.
- Changes your body composition and helps you to have a lean, toned and solid look.
- Prevents the loss of lean body mass that happens from long distance running, dieting and/or aging. Weight gain often happens as your metabolism slows over time due to a loss in lean type II muscle fiber types
- Strengthens bones3 and connective tissue along with muscles.
MYTH #2: Eating little meals throughout the day speeds up your metabolism.
THE TRUTH: Turns out the old notion of eating a meal every few hours to ramp up one’s metabolism wasn’t exactly perfect advice. Small meals throughout the day are helpful in portion control and curbing hunger cravings, but how frequently someone eats has little to do with speed of metabolism. Instead, the quality and quantity of foods have greater bearing on metabolism than how often you eat.
MYTH #3: Eating spicy foods boosts your metabolism.
Finally, a myth that we can (kind of) keep believing! Although it is on a very small scale, hot foods have been shown to play a small roll in increasing metabolic rates. Hot peppers contain capsaicinoid phytochemicals that produce the spiciness of the pepper. The common theory states, they increase the heat your body produces (which takes energy to produce) and enhance fat utilization. They may also help you eat less and potentially feel full longer. It’s not a huge boost, but adding some heat regularly to what you eat may help slightly.
MYTH #4: Skipping meals can lead to weight loss
THE TRUTH: Weight loss is all about creating an energy deficit — ingesting fewer calories than your body expends each day — but creating too large of a calorie deficit can backfire. Our bodies are smart and programmed for survival. Severely limiting calories can make your body think it’s entering a famine and that it needs to do more with fewer calories. Your body adapts to the restricted caloric intake and uses fewer calories to perform the same tasks. So what’s the trick to healthy calorie cutting? Do it slowly and don’t go below your resting metabolic needs—slow and steady weight loss wins the race.
MYTH #5: MOST of the energy you burn is done from workouts and daily activities.
Only 10-30 percent of the calories burned (unless you’re a high level athlete) are actually burned through exercise. Resting Metabolic Rate (RMR) plays an incredibly important role in body composition. However, RMR or Basal Metabolic Rate (BMR) – can account for up to 60-80 percent of a person’s total caloric usage. This is why we often see men being able to consume more calories than women.
Okay. We’ve done it. We’ve spelled out metabolism and discovered the truth behind some common misconceptions. Most days, everyone’s metabolism works pretty well and the most surefire way of giving it a boost is increasing your muscle mass. Aside from that, the best day-to-day metabolic supporting strategies involve getting plenty of sleep, eating a high-protein breakfast, staying hydrated, avoiding skipping meals, and being mindful of food quality. All of these habits, along with adequate movement and exercise can only help you in the long run! – SOL PT & Assoc