Part II: Why is My Metabolism Slow?


You may feel tired, cold or that you’ve gained weight.  Maybe your digestion seems a bit more “sluggish”. You may be convinced that your metabolism is slow. Why does this happen?  Why do metabolic rates slow down? Let’s dive in!


What can slow my metabolism?

A couple weeks ago I shared a post about understanding your metabolism. If you didn’t get a chance to read it you can check it out HERE. Quite often when people seem “stuck” in their journey of weight loss they blame their metabolism.  They think they are doing everything else right but the scale won’t budge. What you need to understand is that there’s a lot more to your metabolism than meets the eye, and the good news is that there are definitely influential factors that you can do something about.

Metabolism includes all of the biochemical reactions in your body that use nutrients and oxygen to create energy.  And there are lots of factors that affect how quickly (or slowly) it works, i.e. your “metabolic rate” (which is measured in calories).

Men tend to burn more calories than women, even while resting. And for most people, metabolism continues to slow down after age 40.

But don’t worry, although you can’t control your age, gender or genetics – we know that metabolic rate is much more complicated than the old adage “calories in calories out”!  In fact it’s so complicated I’m only going to list a few of the common things that can slow it down, and a tip to speed it up.

Examples of common reasons why metabolic rates can slow down:

  • low thyroid hormone
  • your history of dieting
  • your size and body composition
  • your activity level
  • lack of sleep

We’ll briefly touch on each one below and I promise to give you better advice than just to “eat less and exercise more”.

_thyroidLow thyroid hormones

Your thyroid is the master controller of your metabolism.  When it produces fewer hormones your metabolism slows down.  The thyroid hormones (T3 & T4) tell the cells in your body when to use more energy and become more metabolically active.   Ideally it should work to keep your metabolism just right.  But there are several things that can affect it and throw it off course.  Things like autoimmune diseases and mineral deficiencies (e.g. iodine or selenium) for example.

One thing we do know is the importance of Selenium in thyroid health. Thyroid hormone synthesis, metabolism and action require adequate availability of the essential trace elements iodine and selenium, which affect homeostasis of thyroid hormone-dependent metabolic pathways. If you are deficient in either of these minerals your metabolism will be affected.

Try this (Selenium rich) Chocolate Chia Seed Pudding Recipe to give yours a boost.

Tip: Talk with your doctor about having your thyroid hormones tested.

Your history of dieting


When people lose weight their metabolic rate often slows down.  This is because the body senses that food may be scarce and adapts by trying to continue with all the necessary life functions and do it all with less food.

While dieting can lead to a reduction in amount of fat it unfortunately can also lead to a reduction in the amount of muscle you have.  As you know more muscle means faster resting metabolic rate.

Tip: Make sure you’re eating enough food to fuel your body without overdoing it.

beginners-weight-lifting-programs-mainYour size and body composition

In general, larger people have faster metabolic rates.  This is because it takes more energy to fuel a larger body than a smaller one.


However, you already know that gaining weight is rarely the best strategy for increasing your metabolism.

Muscles that actively move and do work need energy.  Even muscles at rest burn more calories than fat.  This means that the amount of energy your body uses depends partly on the amount of lean muscle mass you have.

Tip: Do some weight training to help increase your muscle mass.

Which leads us to…

beginners-weight-lifting-programs-mainYour activity level

Aerobic exercise temporarily increases your metabolic rate.  Your muscles are burning fuel to move and do “work” and you can tell because you’re also getting hotter.

Even little things can add up.  Walking a bit farther than you usually do, using a standing desk instead of sitting all day, or taking the stairs instead of the elevator can all contribute to more activity in your day.

Tip:  Incorporate movement into your day.  Also, exercise regularly.

sleepLack of sleep

There is plenty of research that shows the influence that sleep has on your metabolic rate.  The general consensus is to get 7-9 hours of sleep every night.

Tip: Try to create a routine that allows at least 7 hours of sleep every night. 


I hope this has given you a better understanding of your metabolism and what you can do if you feel yours is slow. Remember, one positive lifestyle change leads to another so begin with just one step at a time and you will start seeing results 🙂

For a selenium rich recipe that makes a nice treat (or have for breakfast)  click here for the recipe. This Chocolate Chia Seed  Pudding hits the spot!

And if you want some help with what to eat and how to workout for a leaner, stronger you, check out my 30 Day Slim & Sculpt Program. You’ll be amazed at the difference 30 days can make!

30 Day Slim & Sculpt











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