The holiday season can be a time of joy, celebration, and indulgence in delicious foods and meals. However, for many, it can also be an emotional and stressful period.

This stress can manifest in our eating habits, leading to what is known as emotional or stress eating.

There are certain foods we tend to eat more of when we’re stressed, and these can affect our health. What’s more, our food choices can influence our stress levels and make us feel worse. Here’s how.

Why we might eat more when stressed

The human stress response is a complex signalling network across the body and brain. Our nervous system then responds to physical and psychological events to maintain our health. Our stress response – which can be subtle or trigger a fight-or-flight response – is essential and part of daily life.

The stress response increases production of the hormones cortisol and insulin and the release of glucose (blood sugars) and brain chemicals to meet demand. Eating when we experience stress is a normal behaviour to meet a spike in energy needs.

But sometimes our relationship with food becomes strained in response to different types of stress. We might attach shame or guilt to overeating. And anxiety or insecurity can mean some people under-eat in stressful times.

Over time, people can start to associate eating with negative emotions – such as anger, sadness, fear or worry. This link can create behavioural cycles of emotional eating. “Emotional eaters” may go on to develop altered brain responses to the sight or smell of food.

What stress eating can do to the body

Stress eating can include binge eating, grazing, eating late at night, eating quickly or eating past the feeling of fullness. It can also involve craving or eating foods we don’t normally choose. For example, stressed people often reach for ultra-processed foods. While eating these foods is not necessarily a sign of stress, having them can activate the reward system in our brain to alleviate stress and create a pattern.

Short-term stress eating, such as across the holiday period, can lead to symptoms such as acid reflux and poor sleep – particularly when combined with drinking alcohol.

In the longer term, stress eating can lead to weight gain and obesity, increasing the risks of cancer, heart diseases and diabetes.

While stress eating may help reduce stress in the moment, long-term stress eating is linked with an increase in depressive symptoms and poor mental health.

What we eat can make us more or less stressed

The foods we choose can also influence our stress levels.

Diets high in refined carbohydrates and sugar (such as sugary drinks, sweets, crackers, cakes and most chocolates) can make blood sugar levels spike and then crash.

Diets high in unhealthy saturated and trans fats (processed foods, animal fats and commercially fried foods) can increase inflammatory responses.

Rapid changes in blood sugar and inflammation can increase anxiety and can change our mood.

Meanwhile, certain foods can improve the balance of neurotransmitters in the brain that regulate stress and mood.

Omega-3 fatty acids, found in fish and flaxseeds, are known to reduce inflammation and support brain health. Magnesium, found in leafy greens and nuts, helps regulate cortisol levels and the body’s stress response.

Vitamin Bs, found in whole grains, nuts, seeds, beans and animal products (mostly B12), help maintain a healthy nervous system and energy metabolism, improving mood and cognitive performance.

5 tips for the holiday table and beyond

Food is a big part of the festive season, and treating yourself to delicious treats can be part of the fun. Here are some tips for enjoying festive foods, while avoiding stress eating:

1. slow down: be mindful about the speed of your eating. Slow down, chew food well and put down your utensils after each bite

2. watch the clock: even if you’re eating more food than you normally would, sticking to the same timing of eating can help maintain your body’s response to the food. If you normally have an eight-hour eating window (the time between your first meal and last meal of the day) then stick to this even if you’re eating more

3. continue other health behaviours: even if we are eating more food or different food during the festive season, try to keep up other healthy behaviours, such as sleep and exercise

4. stay hydrated: make sure to drink plenty of fluids, especially water. This helps our body function and can help with feelings of hunger. When our brain gets the message something has entered the stomach (what we drink) this can provide a temporary reduction in feelings of hunger

5. don’t restrict: if we have a big day of eating, it can be tempting to restrict eating in the days before or after. But it is never a good idea to overly constrain food intake. It can lead to more overeating and worsen stress.

Plus 3 bonus tips to manage holiday stress

1. shift your thinking: try reframing festive stress. Instead of viewing it as “something bad”, see it as “providing the energy” to reach your goals, such as a family gathering or present shopping

2. be kind to yourself and others: practise an act of compassion for someone else or try talking to yourself as you would a friend. These actions can stimulate our brains and improve wellbeing

3. do something enjoyable: being absorbed in enjoyable activities – such as crafting, movement or even breathing exercises – can help our brains and bodies to return to a more relaxed state, feel steady and connected.

For support and more information about eating disorders, contact the Butterfly Foundation on 1800 33 4673 or Kids Helpline on 1800 551 800. If this article has raised issues for you, or if you’re concerned about someone you know, call Lifeline on 13 11 14. In an emergency, call 000.

Saman Khalesi, Senior Lecturer and Discipline Lead in Nutrition, School of Health, Medical and Applied Sciences, CQUniversity Australia; Charlotte Gupta, Senior Postdoctoral Research Fellow, Appleton Institute, HealthWise research group, CQUniversity Australia, and Talitha Best, Professor of Psychology, NeuroHealth Lab, Appleton Institute, CQUniversity Australia

This article is republished from The Conversation under a Creative Commons license. Read the original article.

This is the next article in our ‘Light and health’ series, where we look at how light affects our physical and mental health in sometimes surprising ways. Read other articles in the series.

Exposure to light is crucial for our physical and mental health, as this and future articles in the series will show.

But the timing of that light exposure is also crucial. This tells our body to wake up in the morning, when to poo and the time of day to best focus or be alert. When we’re exposed to light also controls our body temperature, blood pressure and even chemical reactions in our body.

But how does our body know when it’s time to do all this? And what’s light got to do with it?

What is the body clock, actually?

One of the key roles of light is to re-set our body clock, also known as the circadian clock. This works like an internal oscillator, similar to an actual clock, ticking away as you read this article.

But rather than ticking you can hear, the body clock is a network of genes and proteins that regulate each other. This network sends signals to organs via hormones and the nervous system. These complex loops of interactions and communications have a rhythm of about 24 hours.

In fact, we don’t have one clock, we have trillions of body clocks throughout the body. The central clock is in the hypothalamus region of the brain, and each cell in every organ has its own. These clocks work in concert to help us adapt to the daily cycle of light and dark, aligning our body’s functions with the time of day.

However, our body clock is not precise and works to a rhythm of about 24 hours (24 hours 30 minutes on average). So every morning, the central clock needs to be reset, signalling the start of a new day. This is why light is so important.

The central clock is directly connected to light-sensing cells in our retinas (the back of the eye). This daily re-setting of the body clock with morning light is essential for ensuring our body works well, in sync with our environment.

In parallel, when we eat food also plays a role in re-setting the body clock, but this time the clock in organs other than the brain, such as the liver, kidneys or the gut.

So it’s easy to see how our daily routines are closely linked with our body clocks. And in turn, our body clocks shape how our body works at set times of the day.

What time of day?

Let’s take a closer look at sleep

The naturally occurring brain hormone melatonin is linked to our central clock and makes us feel sleepy at certain times of day. When it’s light, our body stops making melatonin (its production is inhibited) and we are alert. Closer to bedtime, the hormone is made, then secreted, making us feel drowsy.

Our sleep is also partly controlled by our genes, which are part of our central clock. These genes influence our chronotype – whether we are a “lark” (early riser), “night owl” (late sleeper) or a “dove” (somewhere in between).

But exposure to light at night when we are supposed to be sleeping can have harmful effects. Even dim light from light pollution can impair our heart rate and how we metabolise sugar (glucose), may lead to psychiatric disorders such as depression, anxiety and bipolar disorder, and increases the overall risk of premature death.

The main reason for these harmful effects is that light “at the wrong time” disturbs the body clock, and these effects are more pronounced for “night owls”.

This “misaligned” exposure to light is also connected to the detrimental health effects we often see in people who work night shifts, such as an increased risk of cancer, diabetes and heart disease.

How about the gut?

Digestion also follows a circadian rhythm. Muscles in the colon that help move waste are more active during the day and slow down at night.

The most significant increase in colon movement starts at 6.30am. This is one of the reasons why most people feel the urge to poo in the early morning rather than at night.

The gut’s day-night rhythm is a direct result of the action of the gut’s own clock and the central clock (which synchronises the gut with the rest of the body). It’s also influenced by when we eat.

How about focusing?

Our body clock also helps control our attention and alertness levels by changing how our brain functions at certain times of day. Attention and alertness levels improve in the afternoon and evening but dip during the night and early morning.

Those fluctuations impact performance and can lead to decreased productivity and an increased risk of errors and accidents during the less-alert hours.

So it’s important to perform certain tasks that require our attention at certain times of day. That includes driving. In fact, disruption of the circadian clock at the start of daylight savings – when our body hasn’t had a chance to adapt to the clocks changing – increases the risk of a car accident, particularly in the morning.

What else does our body clock control?

Our body clock influences many other aspects of our biology, including:

• physical performance by controlling the activity of our muscles
• blood pressure by controlling the system of hormones involved in regulating our blood volume and blood vessels
• body temperature by controlling our metabolism and our level of physical activity
• how our body handles drugs and toxins by controlling enzymes involved in how the liver and kidneys eliminate these substances from the body.

Morning light is important

But what does this all mean for us? Exposure to light, especially in the morning, is crucial for synchronising our circadian clock and bodily functions.

As well as setting us up for a good night’s sleep, increased morning light exposure benefits our mental health and reduces the risk of obesity. So boosting our exposure to morning light – for example, by going for a walk, or having breakfast outside – can directly benefit our mental and metabolic health.

However, there are other aspects about which we have less control, including the genes that control our body clock.

Frederic Gachon, Associate Professor, Physiology of Circadian Rhythms, Institute for Molecular Bioscience, The University of Queensland and Benjamin Weger, NHMRC Emerging Leadership Fellow Institute for Molecular Bioscience, The University of Queensland

This article is republished from The Conversation under a Creative Commons license. Read the original article.