Healthful nutrition

Link between nutrition and health

A growing body of scientific research has now clearly established a direct link between what we eat and our health, both physical and mental. This body of research can be summed up well with the findings published by the World Health Organisation in their 2009 report into global health risk.

In their report WHO concludes that large percentage of populations experience coronary heart disease and Type II diabetes which could be avoided through lifestyle changes (refer infographic below). About one third of cancers could be prevented by consuming a healthy diet, maintaining a normal body weight, abstaining from smoking and being physically active.

Similarly, a healthy diet contributes to our mental health, cognition and memory and reduces significantly, for example, the risk of depression and the ageing of the brain.

Good nutrition from a well-balanced and healthy diet is therefore another cornerstone of a healthy lifestyle.

Navigating the "nutrition maze"

Human nutrition is a relatively new, dynamic and every expanding domain with new research and controversy seemingly popping up every day. Even nutritionists and scientist are often baffled by the wide ranging opinions from experts and contradictions in scientific research and advice. The business potential of nutritional claims often clouds robust evidence and delving into all the actual evidence-based research is virtually a full-time task. Various documentaries, diet books, podcasts etc contain no doubt some evidence-based and useful information but often also selectively analyse nutrition research to demonize particular foods and praise a particular diet.

So what is the right thing to do? Here are my key recommendations based on years of engaging with nutritional science and personal experience.

Firstly, key to adopting a healthy nutrition discipline is to start off with accepting that nutrition is a complex domain with many variables, not the least the reality that there can be huge individual differences between one person and the next. There is no silver bullet, no simple answers nor a specific diet or approach that holds true for everyone.

Secondly, food is there to be enjoyed and it is important that healthy nutrition is part of a wholesome, balanced and well-lived life. Make sure to adopt a balanced mindset around nutrition, avoid fixating on it and prevent it from causing stress and anxiety in daily life. Any benefits you may gain from a focus on nutrition are then likely offset by the negative consequences of increased stress!

Thirdly, focus on the guiding principles covered below that are universally accepted by scientists and nutritionists and take guidance from the prevailing themes that are starting to feature across dietary guidelines issued by governments, Universities and other research institutions (see the dietary guidelines section below).

In what follows, both the terms nutrition and diet are used. Nutrition is defined as the provision of all necessary compounds to the body to maintain life, body and brain function and health. Diet on the other hand is defined as the sum of all foods and beverages consumed and includes dietary habits.

The information provided in this section is not intended as an exhaustive body of information nor does it constitute specific individual advice which should be sought from a qualified nutritionist or dietitian.

Guidelines for healthy nutrition

Below we present seven core principles of a good diet that experts seem universally aligned on. Familiarising yourself with these principles, reviewing to what extent you currently live by them and integrating them more into your dietary habits forms a great start to adopting a healthy lifestyle.

Principle 1: Variety

Our body and brain requires a very wide range of macro and micro nutrients to - just to name a few - provide us with energy, support cell growth and building blocks for neurotransmitters that power our brain and nervous system. Different foods provide different combinations of these nutrients and in order for our body to have access to all of them, variety or diversity in our diet is fundamental.

Foods are generally categorised together on the basis of nutrient similarities into these food groups:

Breads, cereals, rice, pasta and noodles
Vegetables and legumes / beans
Fruit
Milk, yoghurt, cheese and alternatives
Meat, fish, poultry, eggs, tofu, nuts, seeds and legumes / beans

The table below shows the main distinguishing nutrients of each food group. Consuming foods from across each food group provides the first layer of diversity. However to achieve a good level of diversity it also important to consume a variety of foods within each group. For example within the fruit food group, strawberries are particularly high in vitamin C whereas bananas are rich in a number of B-group vitamins.

Principle 2: Wholesomeness and avoid processed foods

The less processed the food you eat the better it will be for you. Wholesome means that the food has been made from whole ingredients as opposed to its "reduced down" derivatives. When food / ingredients are processed the original nutritional make up is reduced and the nutritional power is lost.

The general rule of thumb is that the less processed a food is, the greater its nutrient content. As such consuming mostly wholesome foods complements principle 1 in that it further boosts your intake of a wide range of nutrients.

So opt, as much as possible for wholesome foods and avoid or at least limit the consumption of processed foods such as tinned, frozen, pre-prepared food, fast food, reheated food and in particular those with a high content of preservatives, colours, flavours and other additives you don't recognise.

Principle 3: Plant rich

A diet rich in foods from plant sources is one of the cornerstones of a healthy life, which is supported by substantial evidence from scientific research. The Mediterranean diet in particular has been extensively researched and has been shown to reduce risk of heart disease, metabolic syndrome, diabetes, certain cancers (specifically colon, breast, and prostate cancer), depression, and in older adults, a decreased risk of frailty, along with better mental and physical function.

The Mediterranean diet emphasises eating plenty of plant-based foods, such as vegetables and fruits, whole grains, legumes (like lentils, split peas, chickpeas and cooked dried beans, eg, kidney beans and baked beans) and nuts; replacing butter with monounsaturated fats, mainly from olive oil; but also eating a moderate amount of fish, poultry and dairy products, with little or no red meat.

Hence the word plant rich. You don’t need to become a vegetarian or vegan and not eat meat or dairy. Key is to increase your intake of foods from plant sources and progressively make them your largest proportion.

The recommendation is for food for plant sources to make up about 40% of what you consume across the day. For an average adult the UK guideline is to have at least 5 portions of vegetables and fruits each day and the Australian guidelines advises 5 portions of vegetables and 2 portions of fruit each day. A portion is 80 grams of fresh, frozen or tinned, 30 grams of dried fruit (limited to 1 portion a day) or 150 ml of unsweetened vegetable or fruit juice.

Principle 4: Individuality

Every individual's nutritional needs and what specific diet they thrive on are different and depend on a range of interacting factors, such as age, metabolism, sensitivities, digestion, genetics and so on. It is also important to view nutrition as one aspect in the wider context of a healthy lifestyle as opposed to the sole or primary driver for a long life well lived.

Whilst a complete vegan diet work may work for one person, in order to consume sufficient macro and micro nutrients, it may require more time than is available (and therefore produce excessive stress) for the next person. Putting all your time and attention on your diet and ignore physical activity may actually be worse than taking a more balanced approach across all aspects of a healthy lifestyle. And so on...

So key to success and in particularly also stickability is to figure out what works for you. The reality is that even small changes in your diet, for example reducing your intake of red meats and boosting your intake of fresh fruit and vegetables, can result in significant health improvements and reduce the risk of developing illnesses.

Principle 5: Water for thirst

You will find more on hydration below. In a nutshell, staying hydrated is an essential part of a healtful nutrition approach. Water is by far the preferred option and should be the go-to option, in favour of other beverages and in particular in favour of sugary drinks.

Principle 6: Avoid diet fads

When backed by good research and recommended by a doctor or other health professional, adopting a specific diet has its place. Specific diet regimes have gained in popularity, including detox diets, the paleo diet, the keto diet, intermittent fasting diets, very low-carbohydrate diets. These diets are often used as a strategy to target a specific outcome such as reducing inflammation, addressing digestive issues or on the recommendation of a doctor to treat difficult to control illnesses.

One of those diets is the Dietary Approach to Stop Hypertension (DASH), which was developed to help treat and prevent high blood pressure (hypertension). The DASH diet emphasises plenty of vegetables, fruits and low-fat dairy products, and moderate amounts of whole grains, fish, poultry and nuts.

Be wary though of diet fads we often see in the weight loss domain. These rarely work permanently and are difficult to turn into a sustained habit. They mostly show little or not long term success and in fact can be quite harmful in relation to emotional resilience and self-esteem. A lot of these diets are also not supported with robust and independent research.

A more effective and sustainable approach to enjoying a healthy weight is to build the skills of selecting appropriate foods for your body and eating them in appropriate amounts. Adopting the other 6 principles will support you in doing this.

Principle 7: 80% rule

People in the Blue zones have adopted a mantra that reminds them to stop eating when they feel 80% full, which can make the difference between sustaining a healthy weight or gaining it. They also eat their smallest meal at night and then let things settle down by not eating anything else until the following morning.

Dietary guidelines

Various government organisation, Universities and other institutions canvas the latest scientific research and publish up to date dietary guidelines which can be effectives guides as you refine you diet. Some of the key ones are listed in the Further Reading section below.

The Healthy Eating Plate developed by the Harvard School of Public Health is arguably an infographic that best sums up these various guidelines.

Hydration

Getting enough water is fundamental for good health and optimal functioning, yet studies indicate that as much as 75% of us are chronically dehydrated.

At a high level it is quite easy to see why water intake is important. Our body is made up of about 60% of water and this percentage goes up to around 70% for our brain. In order to keep water at the required levels we need to take in large quantities of water throughout our awake hours.

It is not easy to find a consistent set of guidelines on the amount of water to drink and intake depends on body weight, level of exercise, ambient temperature etc. A general rule of thumb is to divide your weight (in kg) by 30. The answer is the amount of litres you should be drinking each day. So, if you weight 60kg, you should drink 2 litres of water but of course this should go up when you are losing more water through sweating as a result of exercise and / or high ambient temperatures and when you are sick / running a fever.

A rule of thumb is to drink and additional 250ml for every 20 minutes of exercising. For longer exercise activities, adding electrolytes will help maintain the important "charged minerals" which help your body move and perform daily physical activities. Electrolytes include minerals like potassium, sodium, chloride, and calcium. When you lose these minerals, you need to replenish them. Water alone doesn’t quite cut it in this case, which is why drinking a sports drink with electrolytes during a hard workouts that go beyond approximately 90 minutes or, alternatively, adding some coconut water to your hydration bottle is key to replenish these minerals.

A key challenge is that humans are not particularly good at detecting dehydration and feeling thirsty is a late stage symptom of dehydration when low water levels have already started to take its toll. First-stage dehydration symptoms are subtle but once you are tuned into these it becomes easier to stay hydrated:

Fatigue
Dull headache
Less frequent urination
Dark(er)-coloured urine (this is probably the easiest to keep an eye on)
Irritability
Trouble focusing

At a more detailed level, sufficient levels of water are important for the optimal functioning of a wide range of our body and brain systems, including blood pressure regulation, temperature regulation, joint lubrication, waste removal, neurotransmitter (e.g. serotonin) levels and functioning (mood, memory, concentration etc), skin tone and so on. It is also a key aspect of weight management via two mechanisms, reduced food intake (more water gives you a sense of being full) and increased lipolysis (breakdown of fat).

Not all water is treated equally - drinking filtered water so that all excess chemicals are removed is important and it is generally accepted that drinking water from plastic bottles may pose a risk of ingesting plastic particles. At-home and at-work tap filtration systems and using non-plastic drink bottles are a good way to ensure you’re not digesting harmful chemicals like chlorine, which is commonly found in tap water.

Other beverages, such as tea, sports drinks and coffee, count towards your daily intake of hydration. Health experts have long debated this topic and coffee has been thought to contribute to dehydration but this has since been debunked by others. Coffee and tea are thought to have certain health benefits although scientist do not agree on the benefits and disadvantages of particularly coffee. Sports drinks and other similar beverages tend to have a high sugar content so their consumption should be moderated. On the whole it is probably reasonable to conclude that other beverages do contribute to your hydration intake but not to the same extent as water itself - water therefore should form the majority, by quite a margin, of your hydration intake.

There is actually also such a thing as drinking too much water, called hyponatremia, which can result from an underlying medical condition but is usually caused by drinking too much water. This dilutes sodium levels in your blood so that its level is too low which causes the body's cells to swell. This can result in a range of medical conditions, some of which are serious / life-threatening. It is quite rare though and dehydration as a result of not drinking enough water, as opposed to drinking too much, is far more common.

Link between nutrition and health

Navigating the "nutrition maze"

Guidelines for healthy nutrition

Dietary guidelines

Hydration

Further reading