02/05/2017 08:04 BST | Updated 02/05/2017 08:04 BST

Why We Tend To Make Poorer Food Choices When We're Stressed

I have never believed that weight-loss or weight management is as simple as calories in versus calories out. Our bodies are not inert and what contributes to how we nourish ourselves includes what can be complex cultural, psychological and environmental factors.

It is never just the foods you choose and the quantity you eat nor the regularity with which you move your body that impact on your weight. Emotional and physical stress can also tip the balance of the nervous system and subsequently the scales. But it's not always about weight gain, stress can also be a catalyst for people to lose weight - or change their eating habits.

Driving the Stress Response

When you go through a period of prolonged stress, your body is constantly producing the stress hormone adrenalin. This results in inconsistent energy. You fire up and then you crash, and the choices you make when you crash can set you up to fire up again and quite often they are nutritionally of a poor quality.

If you're producing surges of adrenalin that leave you feeling drained when they drop, you're typically going to be drawn to foods that will give you a quick energy boost such as caffeine, sugars or starches. Let's face it. You don't polish off a packet of chocolate biscuits thinking you are going to feel amazing afterwards. It's not a lack of knowledge that leads you to do that--you do it for biochemical or emotional reasons, or sometimes both.

Consuming too much caffeine is a sure-fire way to feel stressed/rushed as it results in the release of adrenalin. You can see how this might be a problem if your body is already producing adrenalin due to the perceived pressures in your life!

Many people feel tired, yet often describe themselves as being wired - yet they continue to consume coffee. Trying to get out of this cycle is of particular importance if you feel jittery when you consume it. Swap coffee for green tea or if that's just unbearable to you, ask for a single shot coffee, notice if you feel calmer and more energised after a week of doing this.

When Stress Leads to Weight Gain

Continual overproduction of cortisol (our long-term stress hormone) can lead to visceral fat gain, the type located inside our abdomen that is strongly linked to inflammation and an increased risk of many diseases. Cortisol is a fat-storage hormone. Historically, long-term stress corresponded with periods of prolonged food shortages such as famines, droughts, wars or other natural disasters. During those times, our body would switch to storing as much energy (fat) as it could since food could be scarce for some time.

These days there is an abundance of food and stress is more often psychological than as a result of physical danger, yet this ancient mechanism for survival is still wired into our body and it doesn't register the stress any differently. Cortisol can lead us to polish off an entire packet of corn chips, even if we've sworn to have only a small handful. This often results in us feeling guilty over a "lack of self-control" afterwards and, while self-control definitely plays a part, sometimes our biochemistry can be driving us to eat more than we know is right for us.

Stress also has a tendency to make food feel more rewarding or comforting, and subsequently we can rely on food to ease our stress. Be mindful of when you're eating to alleviate stress or when you're eating because you're hungry. Typically, the types of food you want will be the clue here! Not many people who are stressed crave a big bowl of kale.

When Stress Leads to Weight Loss

Many people say that during periods of chronic stress or anxiety they lose their appetite or feel nauseous at the mere thought of eating. There is a biochemical reason behind this.

When our bodies produce stress hormones part of this 'fight or flight' response suppresses what it considers non-essential processes such as our digestion, therefore, digestive processes are compromised. Liquids are often beneficial for these people as they're much easier to digest. Try soups, smoothies and slow-cooked foods, such as casseroles which are easy on digestion.

It's Not All About the Food

The most effective strategy for modulating or even eliminating stress is to identify where the stress in your life is coming from, or whether you are driving this physical response through your thoughts and perceptions of pressure and urgency.

This is not always as obvious as it may seem. While there are recognisable triggers, such as work deadlines, financial pressure, relationship pressures and so on - there will also be situations in your life you may never have considered. For example your daily commute, or people in your life that may cause you to feel stressed due to their very nature or your response to them.

It may help to do an experiment where you monitor your state of mind regularly; when you start to feel stressed write down the cause, your thoughts and subsequently your mood. Once you can identify your source/s of stress you can develop your own plan for addressing these factors. Some things in your life will be unavoidable however there will be other things that you can adjust - try to focus on those.