You might be feeling tired, cold or feel frustrated that you’ve gained weight. Or maybe your digestion seems a little more “sluggish”.
You may be convinced that your metabolism is slow.
Why does this happen? Why do our metabolic rates slow down?
What is metabolism and what can slow my metabolism?
Metabolism ultimately includes all of the biochemical reactions in your body that use nutrients from the food you eat and beverages your drink along with oxygen to create energy. There are a lot of factors that affect how quickly (or slowly) your metabolism works ( i.e. your “metabolic rate”), which is measured in calories.
However, we now know that your metabolic rate is much more complicated than the phrase “calories in calories out”! In fact it’s so complicated that I am only going to list a few of the common things that can slow it down.
Examples of 5 common reasons why “Metabolic Rates” can slow down:
Low thyroid hormones
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 practical tips for each point listed!
1. Low thyroid hormones
First of all what is your thyroid gland and where is it located?
Your thyroid is the master controller of your metabolism and is a butterfly-shaped gland with 2 wings or lobes attached to one another by a middle part called the isthmus in the front of the neck in front of the trachea (or windpipe).
The thyroid gland uses iodine and minerals from the foods you eat and beverages you drink to make two of the main and most important hormones called Triiodothyronine (T3) Thyroxine (T4).
The thyroid hormones help to regulate your heart rate, blood pressure, body temperature and the rate at which your food is converted into energy (which is metabolism).
When your thyroid gland produces fewer hormones your metabolism then slows down.
The thyroid hormones (T3 & T4) tell the cells in your body when to use more energy and become more metabolically active. Ideally the thyroid hormones should work to keep your metabolism just right.
However, there are several things that can affect your thyroid and throw it off course. For example, autoimmune diseases, mineral deficiencies (e.g. iodine, selenium, manganes, magnesium) and toxins can all affect your thyroid.
Tip #1: Talk with your doctor about having your thyroid hormones tested with a complete thyroid panel (not just the TSH).
A complete thyroid panel which includes TSH, total T3, total T4, free T3, free T4, reverse T3 and thyroid antibodies (includes thyroid peroxidase antibodies and thyroglobulin antibodies). Thyroid peroxidase antibodies targets looking for autoimmune diseases of the thyroid (Hashimotos or Graves) and thyroglobulin is a protein produced by the cells of the thyroid and used by the thyroid gland to make the hormones triiodothyronine (T3) and thyroxine (T4).
2. 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 it 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 the 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 #2 : Make sure you’re eating enough food to fuel your body without overeating. Avoid crash dieting which can drastically slow down your metabolism and ultimately cause weight gain!
3. Your 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.
Remember that 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 #3: Do some weight training or isometric exercises to help increase your muscle mass. Examples of isometric exercises are yoga postures or some pilates exercises and works on the principle that you can strengthen your muscles, shed fat, and get a toned body if you activate the muscle fibers in the problem area.
Which leads us to…
4. Your activity level
Aerobic exercise temporarily increases your metabolic rate. Your muscles are burning fuel to move and do “work”.
Even little things can add up. Walking a bit farther than you usually do, standing up every 30 minutes at your desk and walk in place for 1 minute instead of sitting all day take the stairs instead of the elevator, park further from the store so you are forced to walk more. These can all contribute to more activity in your day!
Tip #4: Incorporate more movement into your day. Also, exercise regularly.
5. Lack 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.
A lack of sleep increases ghrelin and decreases leptin. Ghrelin is known as the “hunger” hormone that increases your appetite, increases food intake and promotes you to store fat. Ghrelin is mostly made and released by your stomach and smaller amounts are made by your small intestine, pancreas and brain. Leptin is a hormone, made mainly by your fat cells but is also produced in your stomach, heart and skeletal muscles that decreases your appetite.
So sleeping less affects your metabolism by increasing your appetite as your brain fails to signal that you are full, even when you should be satisfied and this leads to extra calories and potential weight gain in addition to storing more fat.
Tip #5: Please create a routine that allows at least 7 hours of sleep every night.