2021 on the horizon you’ll be seeing a lot of information on diet, exercise,
metabolism and weight loss. Here’s an article from my iPhone’s news
feed that raised my eyebrows.
Is a metabolism a magical thing that causes your body to burn extra calories at rest?
If you read the title “25 Nutritionist Approved Ways to Speed Up Your Metabolism” and first sentence “Want to boost your body’s calorie burn even at rest?” there’s definitely some magical thinking implied.
(BTW, we are all much more susceptible to BS that is implied vs. directly stated. This is because when we decode their message it is necessarily in our voice and we are not very critical of what appears to be our own thoughts as we would if someone else was directly stating straight BS.)
Great Place to Start: What Is Your Metabolism?
It’s the sum of all the energy your body expends to live your life. Knowing the major parts of your metabolism will help you make sense of what’s legit and what’s BS. There’s really just 3 parts: Digestion, Staying Alive, and Movement.
Digestion: breaking down your food and converting it into the form your body can use takes work/calories. The less processed the food the more energy/calories it takes. The higher in fat the meal the less energy it takes. The scientific name for this part is TEF (thermic effect of food).
Movement: this is the amount of energy you expend during exercise-based movement and non-exercise movement. The non-exercise portion is called NEAT (non-exercise activity thermogenesis) and you can just think of this as your step count.
Unless you are a professional athlete who trains intensely for 20-30 hours per week, NEAT will always be bigger. This doesn’t mean exercise is unimportant. It’s very important, however the most important thing you can get from formal exercise is strength and muscle mass, or, at least, avoiding losing muscle mass with age and/or weight loss. When you lose muscle your metabolic rate slows down, and all activity consumes less energy.
The last point is crucial: formal exercise is a very small part of our lives. If your super consistent (3 hours per week without ever skipping) it’s only 1.5% of your week. Let’s have realistic expectations of how many calories you can burn in 1.5% of your week. Even if you work so hard you vomit and injure yourself each week (like Crossfit) it’s just not that much, and working that hard severely limits your future workouts because while injuries can be worked around they also suck, but you’re also exhausted and your NEAT goes down. However, safely improving your strength also increases NEAT isn’t that neat?
Staying Alive: the BeeGees were actually the first to document this… this is everything else that isn’t included in digestion or movement. This includes activities such as repair and upkeep of your body, keeping you warm, etc.
The scientific name for this part of your metabolism is BMR (basal metabolic rate).
BMR doesn’t change much in the short term. Losing lean body mass (muscle mass, bone mass, etc.) will lower your BMR. This is what happens when you lose weight without a concern for regular strength training, or getting older without strength training. The lower your BMR the easier it is to gain/re-gain weight and body fat.
Gaining lean body mass will raise your BMR. Gaining muscle mass is very worthwhile, but it is also a slow and difficult process.
Unfortunately, it is quick and easy to lose BMR, and it is hard and slow to raise BMR.