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What is the healthiest diet?

A balanced, healthy diet is the foundation for overall wellbeing and, along with physical activity  and sleep, are the foundation healthspan and preventing and preventing disease. Today we are faced with countless nutritional guidelines and practices, some of which may be conflicting, often written by self-proclaimed experts. This can make eating healthily tedious and confusing. Nutrition is the process by which we obtain, consume and utilise nutrients from food and beverages which comprise our diet.



When we talk about nutrition we must consider quantity and quality - how many calories we consume as well as the source of our fuel. In a world where food is easily available, and the ancestral parts of our brain are constantly telling us to eat, whenever we can, we must be aware of the quantity of calories we are consuming. Over consumption of calories is an ever growing problem and is one of the greatest risk factors of chronic disease. Obesity is a complex disease in which excess fat is stored in your body as a result of consuming more calories than you burn.

Yes, daily activities, exercise, genetics and hormones will affect your body weight but if you are consuming more calories than you burn the body was studies excess calories as fat. Conversely, if you are in a calorie deficit you will decrease body weight. Being in energy  balance is the most, but not only, important aspect of our nutrition.

Different people may achieve the correct energy balance in different ways - some may restrict the time in which they eat (fasting) others may cut down on carbohydrates or eat a mostly plant-based diet. The best way to not over consume calories will be dependent on the individual - whichever method they can consistently follow.


Some key points however include:

  • Controlling your portion size - not eating to the point of being uncomfortably full (the Japanese call this Hara hachi bun me, eat until you are 80% full)

  • Taking time to consume meals - allowing yourself time to feel full

  • Having a basic idea of calorific value of the foods you are eating - certain foods are a lot more calorie dense than others



'Hara hachi bun me', eat until you are 80% full

The quality of our diet is also vital to our overall wellbeing - having a well-balanced, nutritious dietary pattern. Nutrients contained in food are divided into two broad categories - macronutrients including carbohydrates, fat and protein (which are required in relatively large amounts) and micronutrients which include vitamins and minerals (which are needed in much smaller amounts).


Carbohydrates, fats and protein are all essential to our survival. Carbohydrates are our body’s main source of energy and are vital for our survival and are found in a huge variety of foods of which some of which are healthier than others. The three main types of carbohydrates are: sugars, or simple carbohydrates, such as glucose and fructose; starches, or complex carbohydrates; and, fibre which plays an essential role in promoting the health of our gut. High quality sources of carbohydrates include whole grains, vegetables, fruits, beans, pulses, nuts and seeds. Refined carbohydrates should be swapped out for whole foods when possible or kept to a minimum.


Fats are also essential to our health giving our body energy, protecting our organs, supporting cell function, allowing absorption of certain vitamins as well as many other essential functions. There are three main types of dietary fats: unsaturated fats (monounsaturated and polyunsaturated) and includes omega-3; saturated fat which is typically found in animal products; and, trans fat which occur naturally in small amounts in animal fat but are artificially produced and added to many packaged foods. Unsaturated fats such as those found in olive oil, nuts, seeds and oily fish are beneficial to our health, whereas saturated fats such as those found in meats, dairy products and coconut oil should be kept to a minimum, because they increase the risk of cardiovascular disease. Any products with trans fats (such as margarine) should be avoided altogether. 



The third macronutrient is protein which is integral to the structure and function of our body. There are millions of different types but may be broadly classified as: complete proteins which are mainly animal sources of protein; and incomplete proteins which are mostly plant sources. Good sources of protein include fish, lean cuts of meat (to avoid excess saturated fat consumption), eggs, tofu and beans.


Micronutrients include vitamins and minerals which are required in very small amounts, yet are critical to our health as they are involved in practically every process in our body. Having a diverse and balanced diet is the best way to avoid deficiencies in the majority of the population. Certain supplements may be advised, particularly in specific populations such as pregnant women or vegans.


So what proportion of our calories should come from each macronutrient? Though everyone has unique nutritional needs, generally speaking, individuals require between 1.5 - 2 grams of protein for every kilogram of body weight with the remaining calories coming from a mix of carbohydrates and fats. Although certain dietary fats form an essential past of our diet it is important to keep in mind that fats provide many more calories than carbohydrates or protein per gram. We should also aim to consume a diet high in fibre which implies that a substantial portion of diet should be plant-based. Additionally, eating as wide a variety as possible of fruits and vegetables to ensure a diverse range of micronutrients are consumed.


Nutrition studies are notoriously difficult to conduct and interpret. The best dietary plan is the one you can follow consistently most of the time. One which you can adhere to closely for the majority of the time, not the perfect one which you can only stick to for short periods of time. Aim for protein at every meal; a large proportion of your diet should be plant-based - fruit, vegetables , wholegrains; stick to mostly whole foods and minimise ultraprocessed foods; eat healthy fats and drink lots of water. Make small changes to improve your diet - your palate will change as you persist with eating healthier foods. There are no superfoods and equally consuming an ‘unhealthy’ snack once in a while is no reason to feel guilty or derail your efforts. Be mindful of the amount of calories you consume particularly those in beverages. The so-called Mediterranean diet encompasses much of this and has long been linked to better health.


If you would like to test your personal risk factors for developing chronic diseases of ageing, and find out if you have high markers of inflammation find out more about the Longevity Annual health check and download the longevity doctor guide to healthy living.



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