How is diet linked to physical and mental wellbeing?

Reviewed by our clinical team

You don’t have to be a nutritionist or gym bunny to know that a good diet is important if you want to stay healthy. Eating a wide range of healthy and nutritious foods (and avoiding overeating) will help you lower your risk of serious diseases, maintain a healthy weight, and boost your mood and self-esteem. 

If you’re looking for advice on a healthier diet, read on. 

What does a healthy diet look like?

The first thing to establish is what healthy eating actually involves. In simple terms, it’s a case of making sure you get all the essential nutrients your body needs, without having too much sugar, salt or saturated fat. This usually means avoiding or cutting down on processed foods, fast food and ready meals.

Beyond that, a healthy diet is one that is varied and balanced. This means it incorporates all the major food groups, and doesn’t rely too heavily on one type of food. 

There’s plenty of information on this topic at the NHS Eatwell Guide, but some simple tips to get you started include the following:

• Eat more fruits and vegetables. Aim to have at least five varied portions a day, and try to incorporate types that are fresh, canned or frozen rather than dried, juiced or blended in a smoothie. 
• Opt for high-fibre and wholegrain carbohydrates. It’s a misconception that a healthy diet is low in carbs – in fact, starchy foods should make up a third of what we eat. However, it’s best to eat wholegrain rather than “white” carbs e.g. (brown breads and pastas) and high-fibre starchy veg like potatoes with the skins on. 
• Have more beans and pulses. Beans, lentils, peas and other pulses are a great source of protein, fibre and essential nutrients. This makes them an excellent low-fat alternative to protein sources like red meat and processed meat, and a great ingredient for bulking out soups and stews. 
• Make sure you have some dairy or dairy alternatives. Dairy is a great source of calcium, which is vital for bone health, so it’s a good idea to have a little bit of low-fat milk, yoghurt or cheese in your diet. If you don’t drink milk, you can have calcium-enriched soya milk or other milk alternatives. 
• Drink plenty of fluids. It’s good to aim for six to eight glasses of fluid each day if you want to stay hydrated and healthy. Healthy drinks include water and low-fat milks. Unhealthy drinks are those with lots of added sugar. 

The last thing to bear in mind is calorie intake. On average, adult men need about 2,500 calories each day, while adult women need about 2,000. 

Diet and physical health

When it comes to your physical health, there are countless benefits to adopting a healthier diet.

First of all, a good diet means you’ll be eating lots of varied foods and getting all the essential nutrients your body needs. This means you won’t be prone to any deficiencies, which in turn will keep your immune system functioning properly.

Secondly, a diet that’s packed with healthy choices will help you maintain a healthy weight. It will also help you avoid serious health conditions that are directly related to diet, including:

• Type 2 diabetes 
• Heart disease 
• High cholesterol
• (Non-alcoholic) fatty liver disease (also known as NAFLD)

Overall, people who eat a healthy diet that’s high in fruits and vegetables and low in sugar, salt and saturated fat will be less prone to obesity, tooth decay, weak bones, heart disease, and some cancers. 

Diet and mental health

The links between diet and mental health are less obvious and direct than with physical health. However – as you probably know from your own experience – your brain can definitely benefit when you take steps towards a healthier lifestyle. Not only can a good diet give you more energy and help you think more clearly, it can also boost your mood. 

Mind has a guide for people trying to boost their mind with their diet – their top tips include the following:

• Eat regularly to avoid feeling tired, irritable and low, and opt for foods that release energy slowly like pasta, rice, oats and wholegrain bread. 
• Cut back on foods that make your blood sugar rise and fall quickly, like sweets and sugary drinks. 
• Be careful about your caffeine intake, as it can disturb your sleep and heighten anxiety and low mood.  
• Nourish your brain with fatty acids. These are found in oily fish, poultry, nuts, seeds, avocadoes, dairy products and eggs.

Foods to avoid- ultra processed foods

In a nutshell, "bad" foods are usually "ultra-processed foods" (UFP); they have little or no nutritional value and can actually harm you. They might be the main driver for the worldwide increase in obesity, heart disease, diabetes, digestive problems, or non-alcoholic fatty liver disease (NAFLD). Many (big brand) food stuffs are ultra-processed; this means they contain additives, sweeteners, artificial colours, modified fats, white sugar, glucose syrup, or highly processed white flour to make food cheap, attractive, tasty and moreish. This means that it isn't just your classic "fast food" that's bad, but it's many things most of us eat every day: white bread, pastries, biscuits, crisps, soups from a packet, sweetened and colourful breakfast cereals, sweets and treats, some "fruit" yoghurts and deserts as well as sugary drinks.

The issue is that we have grown to love a certain taste or texture and that they are often cheap and easy to prepare.  It may seem difficult to replace these kinds of food at first, but you could start with looking at the list of ingredients: if you see anything you are not familiar with or you wouldn't use in home cooking it's likely to be an ultra-processed food. If a product has more than five ingredients the chances that it is ultra-processed are high.

Reducing the amount of ultra-processed foods, you eat or drink will over time improve your physical and mental health and wellbeing and could potentially stop you from getting diabetes or heart disease.

You can find out more about healthy alternatives here. 

Combining exercise and diet for your mental and physical health

Changing up your diet to make it healthier is a great first step for your body and mind. To make even more progress, try to introduce more exercise into your daily routine. In combination, exercise and diet can have a huge positive impact on your health.

Exercise is known to improve sleep, boost mood and self-esteem, help with weight loss, and reduce your risk of serious conditions like heart disease and depression. To learn more, and for some exercise inspiration, check out this guide from the NHS.

References

https://www.nhs.uk/live-well/eat-well/
https://www.nhs.uk/live-well/eat-well/the-eatwell-guide/
https://www.nhs.uk/live-well/healthy-weight/managing-your-weight/understanding-calories/
https://www.nhsinform.scot/healthy-living/food-and-nutrition/eating-well/health-benefits-of-eating-well
https://www.mind.org.uk/information-support/tips-for-everyday-living/food-and-mood/about-food-and-mood/
https://www.nhs.uk/live-well/exercise/exercise-health-benefits/
https://www.bbc.co.uk/food/articles/what_is_ultra-processed_food
https://nutritionj.biomedcentral.com/articles/10.1186/
https://www.bmj.com/content/365/bmj.l1949