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Macronutrients: what are they and why do we need them?

You’ve often heard the word macronutrients or macros thrown around; perhaps like me, you’ve wondered what each of these individual food groups actually brought to the body and why we need them. What I intend to do is provide you with recipes that are nutrient dense, giving you a balanced intake of a wide variety of both macro- and micronutrients to optimise your health. I’ve touched on each of the macronutrients and explained their role within the body, as well as the value of all-important micronutrients. There are more qualified people and other books that go into much more detail. While I don’t want to bog you down with nutritional dogma, I feel that understanding basic nutrition is essential to gaining control over your own eating. This will help you make your own choices about your diet, while also ensuring that you don’t become deficient in any vital nutrients.

With the plate examples in this book, I aim to show you practical examples of exactly how I incorporate a balance of these important foods into my diet, so that it doesn’t feel as though you’re reading a science book! I’m a very visual person, so for me it is important to see how you actually put together a meal with both taste and nutrient density high on the agenda.

Proteins, fats and carbohydrates: what are they and why do we need them?

Protein

Protein is one of the three macronutrients that the body needs in order to function optimally. Protein is so important in our diet due to the abundance of roles that it performs within our bodies. Proteins make up the enzymes that power chemical reactions, they also make up the haemoglobin that transports oxygen in the blood and are the structural components of things like skin, hair, nails, tendons and ligaments. So it’s quite important that we consume enough to support these basic bodily functions!

Protein is made up of building blocks called amino acids, and there are 21 types of amino acids. Of these, nine cannot be produced by the body and therefore must be derived from the food that we eat. These are therefore described as essential amino acids.

The protein that we eat can be divided into two main sources within the diet: animal proteins and plant proteins. Animal proteins, such as meat and fish, are examples of complete proteins because they contain all nine essential amino acids. Some plant proteins are complete proteins, too, such as quinoa, but most often plant-based proteins such as grains and legumes are missing one or more essential amino acids. However, by combining complementary plant-based proteins they become complete, such as combining rice with beans or hummus with wholegrain pitta bread.

Understanding that protein is essential to optimal bodily function, and isn’t just for body builders, is one of the best lessons I learnt while transforming my diet. Personally, I wasn’t eating enough protein, and so understanding that on average we need to consume roughly 0.8-1.5g of protein per kilogram of body weight was a useful figure to demonstrate how much I needed to be eating. If this is a little complicated for you, try just aiming for a fist full of protein with every main meal, whether that be a chicken breast, some salmon or lentils; ensuring you have a source of good-quality protein at each meal will help you to meet your daily required intake.

Variety is my best advice with all foods, and this can certainly be said for protein consumption. Eating a wide variety of sources of protein will ensure that you’re also taking on a multitude of vitamins and minerals that can also be found in proteins, such as iron in red meat and omega-3s in oily fish.

Lastly, protein is believed to be the most satiating of the macronutrients, which means that it will keep you fuller for longer – yet another reason to ensure that you are eating enough of it!

Carbohydrates

Carbohydrates make up another third of the macronutrients, and are of equal importance to both proteins and fats. Carbohydrates are responsible for providing the body with energy via glycolysis. We often hear of carbohydrates categorised into two groups – complex carbohydrates and simple carbohydrates – but many people feel that this oversimplifies them, giving simple carbohydrates a bad name. For example, apples are a simple carbohydrate, however their nutritional profile is far greater than that of something like simple white sugar, and so calling them a simple carbohydrate is, to a certain extent, demonising a worthwhile ingredient in your diet. For this reason, many practitioners now use something called the glycemic load (GL), which is a development of the glycemic index – a scale that determines how quickly carbohydrate-based foods are absorbed and have an effect on blood glucose levels, considering the portion of food consumed. Without overcomplicating things, foods with a low glycemic load provide a slow release of energy, while foods with a high glycemic load provide a quicker release of energy into the blood stream. There are also other factors worth considering, such as fibre, sugar, protein and fat content found in the carbohydrate.

While I’m not trying to overwhelm you with information, it’s good to understand the food you are putting into your body, and what happens when you eat it. The most important thing to take home here is that both high- and low-GL foods are useful in the diet, and neither should be restricted or feared; but harnessing the ability to select slower-releasing carbohydrates for prolonged energy and satiation may be preferable in many circumstances, and it is certainly something that I tend to stick to the majority of the time.

To sum up, try to go for healthier carbohydrates which come from unprocessed or minimally processed whole grains, vegetables, fruits and pulses and limit the unhealthier forms of carbohydrates, such as sugary fizzy drinks, white bread and sweets, as the sugar in these is very accessible to the body.

Fats

The last of the three macronutrients is fats. Fats have often had a bad reputation over the years, but for optimal health they should never be neglected from the diet.

Fats are generally broken down into three categories. The first is saturated fats, which are usually found in animal sources such as meat, butter and cheese, but can also be found in plant-based sources such as coconut oil. Saturated fats are solid at room temperature.

Unsaturated fats are the second grouping of fats, and are mostly found in plant sources. They are liquid at room temperature, and can be further categorised into two types – mono- and polyunsaturated fats. Mono- and polyunsaturated fats are the fats generally considered to be ‘healthy fats’. Monounsaturated fats include things like olive oil, nuts and some fish oils. Examples of polyunsaturated fats include things like walnuts, chia seeds and sunflower seeds.

The final type of fat found in our diet is trans fats. Trans fats do occur naturally in very small quantities but artificial trans fats are something that should be avoided on the whole. Artificial trans fats are man-made fats produced by hydrogenation, a chemical process that alters the structure of a polyunsaturated fat, and overconsumption of these types of fats has been linked with numerous negative health outcomes. A lot of work has been done by food manufacturers to reduce/remove trans fats from their food, but they do still exist. The best way to spot them is to look for partially hydrogenated fats or vegetable oils on an ingredients list.

So now we know which fats are beneficial to our diets and which we need to ditch, it’s also important to understand the role that fats play within the body. Fatty acids we consume through food help contribute towards an array of bodily functions, from hormone regulation and assisting vitamin absorption to aiding growth and development. Omega-3 fatty acids are fats that appear regularly in my diet, and fall into the essential fatty acids category, meaning that the body does not produce them and so they have to be derived from our food. They can be found in foods such as oily fish, nuts and seeds.

My go-to fats are salmon, coconut oil, avocado, full-fat yoghurt, olive oil and nuts and seeds such as almonds and pumpkin seeds. I personally prefer to cook with coconut oil, which is very high in saturated fat and therefore should be consumed in moderation, so feel free to swap coconut oil for healthy polyunsaturated and monosaturated oils such as rapeseed and olive oil to ensure a balanced and healthy fat intake. However, it’s best to stick to coconut oil for the baking recipes in this book as it’s harder to successfully substitute in these recipes.

While it is important to understand the benefits of fats, it is also worth mentioning that they are almost twice as energy dense as carbohydrates and proteins, with 9kcals per gram of fat. This shouldn’t alarm you, but sometimes it’s necessary to exercise more portion control when eating foods rich in fats.