It is widely recognised that poor eating habits and unbalanced nutrition can have a significant impact on both our physical and mental wellbeing. Unhealthy dietary patterns can contribute to mood changes, low energy, and emotional instability. Fluctuations in blood sugar levels and ongoing nutritional deficiencies are often key contributors. Without a steady and balanced supply of nutrients and energy from the foods we eat, our bodies and minds cannot perform at their best. Below are some common eating habits that can negatively affect mood, concentration, and emotional health:
- Skipping meals. Missing meals, particularly breakfast, can lead to low blood sugar levels, which in turn can make you feel fatigued, dizzy, or irritable throughout the day.
- Cutting out entire food groups. Eliminating major food groups from your diet can make it difficult to obtain essential nutrients. Deficiencies in nutrients such as zinc, iron, magnesium, B vitamins, vitamin D, and omega-3 fatty acids are linked to mood fluctuations, fatigue, and low motivation.
- Eating too many refined carbohydrates. Diets high in processed foods and refined carbohydrates such as white bread, pastries, and sugary snacks can cause rapid spikes and crashes in blood sugar levels, leading to mood swings, cravings, and low energy.
Beyond daily mood and energy levels, the connection between diet, nutrition, and mental health is increasingly being recognised as complex and important. Although researchers are still uncovering the full extent of this relationship, growing evidence indicates that the quality of one’s diet can play a key role in the prevention and management of mental health concerns such as depression, anxiety, and stress-related disorders. Maintaining a nutritious and balanced diet is therefore a foundational part of supporting both physical and emotional wellbeing.
Recent studies have started to explore the biological mechanisms that link diet to mental health. Research has examined how nutrition affects the gut microbiome (the community of microorganisms in the digestive tract), neuroplasticity (the brain’s ability to adapt and form new connections), oxidative stress (cellular damage caused by free radicals), and chronic inflammation (the body’s long-term inflammatory response). These factors are all thought to play important roles in influencing mood, cognition, and resilience to stress.
Poor diet and poor mental health are now among the leading causes of illness, disability, and mortality worldwide.
In 2017, the Global Burden of Disease (GBD) project published a major analysis of 15 key dietary risk factors in adults aged 25 years and older across 195 countries, covering data from 1990 to 2017. The findings were striking and continue to guide public health policy today.
In summary, the research revealed that, on a global scale, most populations are consuming insufficient amounts of whole grains, fruits, vegetables, legumes, nuts, and seeds. Conversely, there is excessive consumption of processed meat, sugar-sweetened drinks, and sodium (salt). These imbalances have significant long-term consequences for both physical and mental health.
The study estimated that in 2017 alone, approximately 11 million deaths worldwide were linked to diet-related causes. The leading dietary risk factors included high sodium consumption (3 million deaths), and low intakes of whole grains and fruit (3 million and 2 million deaths, respectively). These results highlight how fundamental healthy eating is to disease prevention and overall wellbeing.
Global mental health
A 2010 study on the global burden of disease related to mental and substance use disorders found that these conditions represent a major cause of disability worldwide. Collectively, they accounted for more than 175 million years lived with disability and represented 22.9% of all non-fatal health loss across the globe.
Within this group, depression and anxiety were the most significant contributors to disability, accounting for 42.5% and 15.3% of the total burden respectively. These disorders tend to emerge in adolescence or early adulthood, which means they affect individuals during critical stages of education, work, and social development. The long-term impacts on productivity, relationships, and overall quality of life are substantial.
These findings clearly show that the combined effects of poor diet and mental health challenges represent a growing global concern. Together, they continue to have a serious impact on life expectancy, quality of life, and overall health outcomes for populations worldwide.
The whole diet approach
The “whole diet” approach is a more holistic way of looking at nutrition. Earlier research often focused on the impact of single nutrients — such as folate, omega-3 fatty acids, or vitamin D — on mental health. However, people do not consume nutrients in isolation, and our diets are made up of complex combinations of foods that interact in various ways to influence health and mood.
For this reason, the whole diet approach emphasises the quality and balance of the entire eating pattern, rather than focusing solely on individual nutrients. This perspective recognises that a diverse, nutrient-rich diet supports optimal mental and physical function, whereas highly processed and nutrient-poor diets can increase risk for poor health outcomes.
According to this approach, and supported by scientific evidence, a high-quality diet is generally characterised by the following features:
- A high intake and wide variety of plant-based foods, including vegetables, fruits, whole grains, legumes, nuts, and seeds
- Moderate consumption of quality proteins such as seafood, lean meats, dairy products, and plant-based protein sources
- A low intake of highly processed and refined foods, added sugars, and trans fats
Importantly, evidence from multiple large-scale studies has demonstrated a direct relationship between the quality of one’s diet and the likelihood of developing common mental health disorders. People who consistently follow a nutrient-rich, balanced diet are less likely to experience depression and anxiety compared to those who consume highly processed or nutrient-poor foods.
Although there is still more to learn about the specific effects of different dietary patterns on mental health, current research strongly suggests that a nutritious diet can have a protective effect. Good nutrition supports brain function, stabilises mood, and enhances overall wellbeing. In fact, a healthy diet is now considered just as important for mental health as it is for physical health. Below are some simple, practical steps you can take to support your mental and emotional wellbeing through healthy eating:
- Eat regularly throughout the day to maintain steady energy levels
- Reduce refined sugars and prioritise wholegrain foods for longer-lasting energy
- Include a source of protein with every meal to promote satiety and balance
- Incorporate a wide variety of nutrient-dense foods into your daily meals
- Include omega-3 rich foods, such as oily fish, walnuts, or chia seeds
- Maintain a healthy weight through balanced nutrition and regular activity
- Stay well hydrated by drinking plenty of water and limiting sugary drinks
- Engage in regular physical activity to support both mental and physical health
Following a consistent and balanced eating plan can help you feel more energised, improve focus, and support your mood. However, while nutrition plays a vital role in emotional wellbeing, it should not replace professional care when needed. If you have ongoing concerns about your mood or mental health, it is important to seek guidance from a qualified healthcare professional who can provide individualised support and treatment options.
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