There’s a lot of different theories surrounding metabolism. From what it is, ways to boost it, and what lifestyle choices actually make a difference to how it works. So we’ve found out all the essentials you need to know to help make sense of your metabolism!
What Is Metabolism?
Your metabolism is not a ‘thing’ as such, like your heart, lungs or other organs. It’s the collection of natural processes that occur in your body to keep you alive. Just like breathing isn’t a physical thing but more of a process. Your metabolism is the sum of the physical and chemical processes that produce energy to allow your body to do all it needs to do.
How Does Metabolism Work?
As your metabolism is a whole range of processes producing energy in your body, it needs to be told how fast or slow to do them. This is where your thyroid plays an important role. It is the ‘moderator’ of your metabolism, overseen by the pituitary gland ‘the Manager’, and the ‘boss’ - your hypothalamus! Your hypothalamus sends signals to your pituitary, which sends out signals to your thyroid to release hormones to either slow or speed up your metabolism.
The pituitary affects the thyroid gland by producing a hormone called thyroid-stimulating hormone (TSH), which prompts the thyroid to release more T4 and T3. If there is too much T4 circulating in the blood, the pituitary reduces the amount of TSH produced, which then causes thyroid activity to slow. If there is too little T4, the pituitary increases the amount of TSH. In this way, T4 and T3 levels in the blood are kept relatively constant.
What Affects Your Metabolism?
Your metabolism can be affected by a range of things including:
- body composition i.e. muscle-to-fat ratio
- physical activity
- overall lifestyle
However, how much your metabolism is affected by each varies greatly, and typically, the things you can’t change tend to affect your metabolism the most e.g. age and gender.
To keep your metabolism, and therefore all the processes in your body, running smoothly you need to make sure that you’re giving your body the fuel it needs - energy. Each metabolic process in the body requires energy to occur. In fact 60-70% of your total daily energy expenditure (TDEE), calculated according to your age, gender, weight, height, and physical activity levels, is used up by vital metabolic functions. That’s your Basal Metabolic Rate (BMR). To find out your BMR and TDEE, click here.
Can You Speed Up Your Metabolism?
Your metabolic rate is the rate at which your body burns energy to function. There are a few ways you can increase your metabolic rate. But first, let’s break down how the energy, or calories, from what you eat typically gets used:
- 60-70% vital functions such as breathing, heart rate, and body temperature (this is your BMR - the amount of energy you need just to survive if you did nothing but sleep very still)
- 15-30% usually goes towards daily activities such as physical activity, housework, gardening, gym workouts, etc
- 10-15% to your digestion - the functions associated with the breakdown of the food and drink you eat into compounds the body can use to repair, rejuvenate and function optimally
As you can see, the majority of the energy we consume is burned up just by existing! You can increase your metabolism by exercising and moving more, and eating regularly, but they won’t make as big of an impact as you may have originally thought!
Which foods support a healthy metabolism?
There are some foods that do help to fire up your metabolism, but the effect is minimal and only for a short period of time. These include spicy foods such as chili because of its heat, caffeinated beverages due to their stimulatory effects, and high protein foods as they take longer to digest. However, it’s much more important to focus on a healthy diet and lifestyle in general. This includes:
- Eating a wholefood based, minimally processed diet.
- Drinking plenty of water each day.
- Eating plenty of vegetables to boost nutrient intake and dietary fiber.
- Reducing intake of refined foods such as sugars, flours, processed, packaged foods, and fast food.
- Opt for lean protein sources that fit your dietary needs e.g. lean meats, beans, and legumes.
- Consuming fats from wholefood sources including nuts, seeds, olive and coconut oil. Fish, hemp seeds and chia seeds are also fantastic sources of anti-inflammatory omega-3s.
- Eating to feel satisfied, not full. Monitor your portion sizes and try to eat slower to give your body a chance to tell you you’re full before overdoing it. A healthy weight is important for a healthy metabolism.
- Iodine-rich foods. Foods such as seaweed and seafood are rich in iodine, which is an essential nutrient required by the thyroid gland to manufacture thyroid hormones. However, both iodine deficiency and excess iodine can be a problem, so iodine supplementation is generally not helpful and can often exacerbate any issues that may be present.
- Consuming a source of selenium regularly is important as it’s a necessary nutrient for proper thyroid function. Brazil nuts, tuna, crab, and lobster are high in selenium, but you can also get some from sunflower seeds, lean meats and mushrooms.
- Avoiding processed, non-organic soy products and limiting organic soy products to minimize their potential goitrogenic effect on thyroid function.
- Consuming cruciferous vegetables such as cabbage, broccoli, and Brussels sprouts cooked. Heating them denatures much of their potential goitrogenic effects.
- Spending 10-15 minutes in the sun getting Vitamin D to prevent deficiencies commonly associated with thyroid issues.
- Keeping active. Exercise helps to boost your metabolism, manage your weight, and reduce your risk of a whole range of health conditions that can be even harder to manage with a thyroid condition. Make sure to include weight-bearing exercises to boost your muscle-to-fat ratio. The more muscle you have, the more energy you need to burn to function and maintain that muscle mass daily so your metabolism gets a boost!
Want to learn the truth about your thyroid and what may happen when your thyroid is not functioning properly? Read this article which reveals all, including what you can do to do to detect and manage a variety of thyroid conditions.