Are You Breath Fat?

Are you “breath fat”?

We all know that if we eat more calories than we expend, it affects our weight and, in the long run, our health.

But did you know that the same is true of the breath. If you breathe more than your metabolism requires then it has some pretty serious impacts on your health and may be at the root of several conditions you would never have associated with your breath.

We all breathe, it’s what keeps us alive. We rarely even think about it – after all we’ve been doing it about 17,000 times a day since we were born. So we must be pretty good at it, right? Well not necessarily. We can quite easily slip into a breathing pattern disorder that can become a really hard habit to break (yep, reversing 17,000 times a day x 20+years!). Mouth breathing is a classic breathing pattern disorder and you can learn more about that here. In this article I’m going to look at what happens if you breathe too much (hyperventilate). What happens when you get “breath fat”?

Breath Basics

First some of the basics of breath. The amount we breathe is calculated by multiplying the number of breaths we take in a minute by the volume of air we inhale with each breath. The rule of thumb is that at rest we shouldn’t breathe more than 6 litres of air a minute. That can be 0.5 litres per breath x 12 breaths, or 1 litre per breath x 6. Anything above that is over-indulging.

Breath is all about chemicals – oxygen and carbon dioxide. We tend to think that oxygen is the good guy and the more of it we can get the better. Carbon dioxide is viewed as a waste product, something to get rid of on the exhale. However, carbon dioxide is a bit more important than we give it credit it for.

Firstly we breathe in as a result of carbon dioxide, not oxygen – receptors in the body sense when the carbon dioxide level rises and this sends the message to the diaphragm to breathe in.

Secondly due to the body’s need to balance the pH level at all times, oxygen doesn’t get released to the cells unless carbon dioxide is present (for those of you who would like to know more about this, Google the Bohr effect). You can take in as much oxygen as you like but if your carbon dioxide level is low, the haemoglobin will hold onto the oxygen and most of it will just be exhaled.

So we know that if we eat too much for our metabolism we get fat. What happens if we breathe too much?

Well, you’re quite possibly inhaling more oxygen, but more importantly you’re exhaling more carbon dioxide than your body is producing (CO2 is produced when your cells combine oxygen with glucose or fat to make energy. If you’re exercising your body produces more). As a temporary event, such as a shock or short-lived stressful event your body can cope with a bit of over-breathing and balance is soon restored. Sustained over-breathing is a different matter.

Over- breathing or hyperventilation can be caused by illness, prolonged stress, pharmaceuticals, hormone changes (progesterone encourages over-breathing), sugary foods & caffeine, and other causes. And we’re not talking the traditional view of hyperventilation, really rapid breathing. Hyperventilation is breathing in excess of the metabolic needs of your body. The breath can be erratic, or punctuated by lots of breath holding. It may be audible even at rest. Or it may appear completely normal apart from the odd yawn or sign which can be enough to sustain lower levels of CO2.

If over-breathing is sustained (anything from 6-72 hours is enough) then your carbon dioxide store depletes. Your body gets used to a lower level of carbon dioxide and resets the trigger point for an inhale – whereas before it was say 40mmHg of CO2, now it’s 35mmHg. You become less tolerant to CO2. When you exercise and more CO2 is produced you need to breathe more as the inhale response is triggered quicker. You also need to blow off carbon dioxide to stay at the lowered rate. And not only that, at rest you’re having to breathe more to keep the carbon dioxide level low.

What effect does hyperventilation and a lower carbon dioxide level have in the body?

1/ Carbon dioxide is a vasodilator.

It dilates smooth muscle which is found in blood vessels, the digestive system, the bladder and eyes. Lower carbon dioxide means that the smooth muscle is more contracted which is basically the fight or flight reaction of the body. A contracted digestive system means that peristalsis doesn’t happen as efficiently. The system is tense and digestion is impaired. Blood pressure is increased as the arteries and veins don’t dilate.

2/ Low carbon dioxide levels activate the sympathetic nervous system, the stress response of the body.

After all breathing is pretty crucial to our survival! If our airways constrict even a little, our brain senses a threat. Cue the stress response. Think raised blood pressure and heart rate. Poor digestive function. Anxious or hypervigilant feelings. Raised levels of adrenaline and cortisol. And impaired immune function.

3/ Over-breathing and the resulting lowered carbon dioxide levels affects the body’s pH balance.

Initially the body become more alkaline as CO2 levels drop and an increase in lactic acid balances the change. However this is short term – longer term the body starts to excrete bicarbonate via the kidneys. Bicarbonate is the body’s pH buffer. It is used to neutralise acid in the body such as acidic food. As the pH buffer is dumped, the body becomes less able to deal with acidic foods such as sugar and refined foods. Vital minerals, such as magnesium, are also dumped with the bicarbonate, leading to mineral deficiencies. A balanced pH level is also crucial to the functioning of our digestive system – when it’s off, it produces an unfavourable environment for our digestive enzymes. Our ability to absorb nutrients is diminished leading to nutritional deficiency.

4/ Lowered carbon dioxide means that haemoglobin does not readily give up oxygen.

Less oxygen gets to the muscles and cells. More energy thus has to be produced anaerobically, ie without oxygen. This involves fermenting glucose. It’s much less efficient and the by-product is lactic acid – muscles become fatigued and sore. The body struggles to maintain its pH level too. With less oxygen getting to the brain, brain-fog, poor memory and mental fatigue can ensue. And inefficient oxygenation continues during the night – the body is unable to repair itself properly and waking tired is not uncommon. Recovery from illness takes much longer.

5/ It’s a vicious circle.

Over-breathing leads to more over-breathing. It feels like you need to breathe more to service the lack of oxygenation – and of course, it’s the opposite, the more you breathe, the more CO2 you blow off and the less oxygen delivered. It’s a vicious circle. With an elevated respiration rate, your heart rate increases. Heart rate variability is reduced meaning the nervous system goes out of balance and you are less resilient to stress. With the mistaken belief that you need more air, it can also be tempting to switch to mouth breathing with all the damage to health that can bring. And all that breathing uses energy. And quite often requires accessory muscles around the shoulders and neck to get involved leading to tension and pain.

6/ Carbon dioxide is a natural anti-oxidant

Cellular respiration transforms glucose and oxygen into energy (ATP). It also produces free radicals, altered oxygen molecules, that, unchecked, can attack and damage cells. They are often cited as reasons for premature ageing and linked to cancer & other conditions via oxidative stress (a bit like our body rusting). Our bodies are designed to handle free radicals and, to all intents and purposes, neutralise them. When our carbon dioxide levels are normal, CO2 provides a protective role against free radicals and the damage they can cause. Rather than disrupting our body’s natural capacity to heal by taking expensive antioxidant supplements, maintaining a healthy level of carbon dioxide is a more efficient solution.

Are you an over-breather?

Taking into consideration all of the above, if you suffer from any of the following, it may be worth assessing your breathing pattern for signs of carbon dioxide deficiency and hyperventilation:

Panic Attacks and Anxiety


Chronic Fatigue


Irritable Bowel Syndrome

Acid Reflux





Restless Leg Syndrome

Sleep Apnea

Muscle Cramps or Pain


Myofascial Pain

Mood Swings

Poor Memory

Swollen Lymph Glands



Brain Fatigue

Food Cravings




Poor Circulation



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