Three Metabolism Myths, Busted

Three Metabolism Myths, Busted

Three Metabolism Myths, Busted

As I said in the first post of this series, the metabolism is one of the most easily-misunderstood physical processes out there. I get it – the concepts are nuanced, and there are many independent and dependent variables that can make it a complex topic. There are many metabolism myths out there.

However, the problem is that when we don’t understand something, it often creates vulnerability to fear-based marketing. When we don’t have a firm grasp of how something in our body works, we will respond more easily to scary morning news stories, unsettling articles we see on Facebook, and MD-authored health books shouting from the shelves of Barnes and Noble.

It’s easy to get overwhelmed, and tugged around by trends. But like I said a few weeks ago, the antidote to fear is knowledge. And when you have a strong base of knowledge, you’re impervious to fad diets, “new” research, and click-bait journalism.

So far, I’ve covered:

Today, I’m going to follow up on what we’ve covered in the first few posts by tackling three myths that I know to be prevalent. They are questions and concerns that I hear often from clients, and it’s completely understandable that these concepts are confusing.

I want to be clear as I begin that these myths aren’t outright lies – some of them are actually quite close to being true. The myth may be based on a kernel of truth, but has been distorted through the lens of bad journalism, urban legend, and old-wives’-tale-style reasoning.

If you have additional questions about the metabolism after you read this post, feel free to shoot me an e-mail to ask away! You can also find my online health and fitness community on Facebook, to continue the conversation!


Our metabolism slows dramatically as we age. 


Our metabolism slows somewhat as we age. 

This is one of those myths that is almost true – which makes it much harder to analyze.

Yes, the resting metabolic rate does slow with age. However, it’s not the off-the-cliff drop in function that many people sense.

There is a gentle decrease in resting metabolic rate for a variety of reasons – less growth hormone, less testosterone, less thyroid function, and more – but the primary reason that people experience a slower metabolism is a slower lifestyle, not a slower metabolic rate.

As we age, life tends to present less and less opportunities to move. Becoming more sedentary is a habit that accrues over the lifespan due to many factors, such as:

  • Younger children growing up (not running after toddlers anymore)
  • Work
  • Increased life responsibilities
  • A sense of “age appropriate” activities
  • Fear of injury

That last point is an important one. Many people, as they age, become increasingly fearful of what exercise could do to them, instead of for them. It becomes a self-perpetuating cycle – the more sedentary someone is, the more creaky and uncomfortable they feel, which – as a result – makes exercise less and less appealing.

The only way to bust this myth for yourself is to get more active. Get back in the driver’s seat, instead of letting your self-limiting beliefs about aging drive the car. Do anything! Join a gym. Start walking. Get a personal trainer. Just get up, and get moving!

If you develop an extremely consistent exercise habit, you’ll be surprised at how much of your metabolic rate is within your control – and how much more youthful you’ll feel!


Your metabolism can be permanently damaged. 


You can greatly affect your metabolic rate by dieting and extreme weight loss, but recovery is possible, and even quite likely.

Our perception that we can completely screw up the metabolism long-term is a little off-base.

Here’s the important first question: why is metabolic rate affected in the first place?

Essentially, when you restrict calories and lose weight, your body buckles down and reduces metabolic rate in order to prevent further weight loss.

Here’s the second question: how does the body do this?

Your metabolism slows down when you lose weight, first of all, because there is simply less body to maintain. A smaller body takes less work to run. However, there is another aspect to metabolic adaptation, which is your body’s natural defense against further weight loss – when you restrict calories too much, for too long, your body will drop hormonal functions to cause you to slow down and burn less calories. You’ll feel more tired, and less jazzed about any kind of exercise, even walking.

In other words, your metabolic rate slows down more than would be justified by the weight loss alone. This is metabolic adaptation. This can make it harder to lose weight over time. If your diet change (and your exercise change) is too extreme, your body will interpret it as stress, ramp up cortisol, suppress your thyroid (among other hormones), and decrease your energy.

But the important thing to remember is that this only happens if you diet and exercise too hard, and even if you do, it’s reversible. 

Final question: what’s the solution? 

  • If you are at the beginning of your weight loss journey, here’s my advice: only reduce calories to the point that you lose weight while feeling good. Don’t look for huge losses – just enough to keep losing weight while maintaining good levels of energy. You literally want to be eating as much as you can while losing weight each month (not each day, or even each week). This will help to protect against the change in hormonal function.
  • Find the right balance with exercise. Don’t over-do it to the point that you are lying in a puddle of sweat on the floor at the gym every day, but also make sure to boost your NEAT and keep it moving as much as possible. Strike the right balance between effort and recovery, all within the context of a high level of low-intensity activity (walking, gardening, household chores, etc.).
  • If you have been dieting a lot, and suspect that your metabolism is now out of whack, I suggest going back into maintenance mode. Don’t keep troubleshooting to try to lose weight, and most of all, don’t double down. Take a month or two off of diet-related weight loss attempts, and simply figure out what lifestyle (including exercise) produces maintenance. Once you feel secure in your maintenance oriented habits (and your weight has stabilized for awhile), then you can probably safely drop a few hundred calories back out of your diet while maintaining your exercise habits.
  • Think of stress as a big picture. Too little calories and too much exercise are just two aspects of stress. There’s also lack of sleep, work stress, emotional stress, and more. I advise clients to also get life stress under control by (1) sleeping consistently, (2) becoming more reflective/meditative, and (3) making actual changes to time management habits and personal boundaries.
  • If you are a “lean dieter” – someone who is already in the healthy BMI range and trying to get leaner – be extra mindful of these concepts. There’s nothing wrong with wanting to see your abs, but make sure to be organized, consistent, and moderate in your approach, avoiding all-or-nothing thinking. Most of all:
  • Listen to your level of energy. If you are on a weight loss journey and you are consistently experiencing drowsiness, lack of motivation to exercise, trouble sleeping, or crankiness, listen to these red flags, and take a maintenance break like I suggested above. It’s possible, and likely, that something you are doing is stressing out your body and causing this hormonal slow-down. During the maintenance break, take the opportunity to address your other stress issues!

But remember: you’re going to be okay! The metabolism is amazingly plastic. Otherwise, people could not recover from near-starvation or anorexia. If you have had a brush with your metabolic rate, remember that once you are consistently eating enough to signal to your body that everything’s okay (and this includes carrying a healthy amount of body fat), your metabolic rate will return to your normal levels.


There are metabolism-boosting foods. 


Some foods require more energy for your body to process, but in general, your metabolism is very loosely related to the actual foods you eat. 

I would look at this from an entirely different angle. Instead of asking, “What can I eat to make my metabolism speed up?” I would ask, “What can I eat to help me feel more satisfied while consuming more nutrients and less processed foods overall, so that I improve my health in the long run?”

Trying to “speed up” your metabolism is, frankly, shortsighted. The only way, technically, to increase your energy needs is to increase your levels of exercise and activity. However, most people experience weight loss setbacks because of diet strategies, not because of their metabolic rate.

The foods that will lead to long-term weight loss are the ones that you can consistently consume in moderation that are satisfying, nutritious, and easily portion-controlled.

As we discussed before, try to avoid being aggressive in your dieting strategies. Instead, re-shape your eating by thinking about:

  • Your personality and how you treat/handle food
  • Which habits may need the most attention
  • How you can take care of yourself to avoid relying too heavily on food
  • How you can eat more protein and more vegetables

If you take care of those aspects of your eating, you will not only take care of your metabolism, but you will also build habits that will promote long-term maintenance of your weight loss goal.

Can you think of any other common myths you’ve heard about the metabolism? Let me know!

Follow-Up Questions from Last Week

If you want to jump into this free healthy living project (with weekly strategies to try out), sign up on this page to get these questions delivered directly to your inbox each week!

Last week in “Calories In” (Part I and Part II) we explored how our body takes in and uses energy through food.

Answer the following questions about your experiences with last week’s posts:

  • Question 1: Have you ever experienced the effects of dieting too hard, too fast? What was that like for you?
  • Question 2: What would it mean for you to create a “maintenance lifestyle,” now?
  • Question 3: Did you learn anything new from the approach to calorie counting in the”Part II” post?

E-mail these answers to me! 

Leave a Comment

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Wordpress Social Share Plugin powered by Ultimatelysocial