What are Macronutrients? This is the topic for today’s blog.
Macronutrients are made up of carbohydrate, fat and protein, and are the nutrients give us our energy. Carbohydrates give us approximately 3.75kcals per gram of energy, protein gives us 4kcals per gram and fat gives us a whopping 9kcals per gram of energy. It’s no surprise then that fat is seen as the bad boy in terms of the macronutrients. However, as in life, things are not always quite what they seem and there is variability within each macronutrient.
All three are comprised of the elements, carbon, oxygen and hydrogen and in protein you will also find nitrogen. The structural arrangement of these elements within each of the macronutrients gives them different properties.  For example, how they will be recognised and used within our body’s.

Carbohydrates

Let’s start with carbohydrates, or carbs as we more commonly refer to them. And who some say are the most controversial. Current dietary recommendations are that we should derive approximately 50% of our daily calories from carbs. They are mainly comprised of starches, sugars and fibre. They are an important source of energy, but also determine the composition and consistency of the waste matter that we eliminate from our bodies…in other words our poo…no more on that‼.

Starch

Carbs are usually thought of as either simple carbs or complex carbs. Complex carbs such as starch are found in things like potatoes, lentils, rice and pasta.  It is also found in lots of fruits and vegetables in differing amounts, like dried fruit, sweet potatoes, carrots, swede, turnips.  In fact most vegetables that grow under the ground as well as a few that grow above ground, like green peas and corn.
Starchy foods can help us to feel fuller for longer by slowing down the speed at which glucose/sugar enters the blood and giving a slower release of energy. The key to starchy foods is to make sure they contain a lot of fibre.  So eat lots of beans, pulses, legumes and wholemeal versions of bread, pasta and brown rice.  As well as fruit and vegetables.

Sugar

Sugars are so much more that what we add to our tea or sprinkle on our cornflakes. There are a few different types of sugar that we eat in our diet that you might recognise from the ingredients lists on food packaging, glucose, fructose, lactose, maltose. These are classed as simple sugars and we are much easily able to digest them. They are very useful when we are in need of a quick energy boost.
A lot of us though, are more likely to turn to overly sweet and overprocessed snack foods.  They taste good and give us that quick boost. We would be better to grab a piece of fruit which contains fructose, so is easily digested and contains good sources of healthy fibre.  That is why it is always better to eat a whole fruit rather than drink the juice, which really is just sugar.
Generally speaking, the trouble with simple sugars is that if we eat more than we need (and a lot of us do), they are easily converted into fat.  Yes, disappointingly, sugar can be turned into fat‼

Just to complicate things even further we have to make the distinction between naturally occurring sugars and added sugars. Naturally occurring sugars, are found within the structure of the plant fruit, leaf, root etc. And added sugars (mainly fructose or sucrose) are sugars that are added to foods during the manufacturing or cooking process.
Recommendations are that we limit added sugars to less than 5% of daily energy intake. For women this is only about 100kcals a day…so that can of coke is out (139kcals).  Sadly it’s also a no to the snack size Mars bar to help you work, rest and play (151kcals).

Dietary fibre

So, the last type of carb I am going to tell you about is dietary fibre. This is a form of complex carbohydrate and is comprised of the plant cell walls, non-digestible oligosaccharides and resistant starches. Non-digestible oligosaccharides are naturally occurring in many plant foods.  For example bananas, garlic, asparagus, onions and artichokes (right up there on everyone’s shopping list, I’m sure). Because of their structure, they are resistant to the digestive enzymes in the intestines and are instead fermented in the colon by gut microbes (have you read the one on gut bacteria?).
Resistant starches are just what they ‘say on the tin’ and are resistant to digestion due to a lack of or insufficient amounts of enzymes and they are also fermented in the colon. This is beneficial for gut health. They can be found in unripe bananas, peas but also in pasta and potatoes, particularly if you pre-cook, allow to cool and then reheat with a creamy sauce. Another example is toasted wholemeal bread that has been toasted from frozen. This is food science and a bit like some of our carbs…complex!
Dietary fibre has the added benefit of promoting friendly gut bacteria. This is very important for reducing the risks of dietary related diseases such as cardiovascular disease, type 2 diabetes and colorectal cancer. So hopefully, you see, not all carbs are equal…so what about protein?

Protein

This is a little more straight forward in terms of our digestion but don’t say that to a biochemist, they just love proteins! The basic unit of protein is an amino acid. These are known as the building blocks of life, as they form the basis of all our cells and tissues and a whole lot of other things too like hormones, enzymes and antibodies (very important for fighting infections).
There are about 20 amino acids that we need to function normally. Half of them we can make ourselves within the body, and half we need to get from our diet.  These are known as essential amino acids. If we eat meat then we get all of these essential amino acids from animal products, if we are vegetarian or vegan then we need to think about complimentary contributions.
Protein is found in all plant foods but particularly in wholegrains, legumes and beans. That is why the rule of thumb is to combine a grain and a legume or bean…and voila!  Beans on toast (wholemeal obvs) will provide the full complement of essential amino acids.

Fat

And lastly, to fat…the bad boy of the macronutrients…or is it? As mentioned earlier, fat contributes 9kcals per gram, however, the recommendation is that we derive up to a third of our calories from fat.
Fat is essential.  True it is the main energy store in the human body and many of us store a bit too much of it. But it is a major component of every single cell membrane in the body.  It helps to make the steroid hormones of oestrogen, progesterone, testosterone (recognise the names of any of these?)  It also contains the fat-soluble vitamins A, D, E & K that we consume at the same time as we consume fat. Not only that but it gives texture and stability to many of the foods we eat making them much more palatable.  Sometimes too palatable, particularly when combined with some of those lovely simple sugars into things like chocolate and ice-cream‼

Not all fats are equal

The thing to remember about fat is that not all fats are equal, in the same way that not all carbs are.
Fats are categorised into unhealthy saturated fatty acids (SFA), and healthy fats; polyunsaturated fatty acids (PUFA) and monounsaturated fatty acids (MUFA). SFA tend to come from animal sources and PUFA’s and MUFA’s from plant sources.
We tend to think of SFA as fats which are solid at room temperature, think butter, lard and beef dripping.  Whereas PUFA’s and MUFA’s tend to be liquid, at room temperature, i.e. olive oil, vegetable or seed oils. There are always exceptions to the rule and the very popular coconut oil is solid at room temperature, mainly due to the high content of SFA’s.
Healthy fats also include omega 3 fatty acids such as DHA and EPA. You might recognise these from the labels if you have taken any fish oil capsules. For vegetarians and vegans the other type of Omega 3 fatty ALA can be found in seeds (particularly flax/linseed oil) and nuts. Omega 3 fatty acids are very important for cell membranes but also for neurological and cognitive development.

The take home message here is that all calories are not equal.  The types of calories you choose to eat will impact on your health and that of your baby, so…

• Eat plenty of leafy greens, citrus fruits, berries, in fact all fruit and veg (eat a rainbow of colour) wholegrains, beans, wholewheat bread/pasta for fibre and complex carbs, vitamin C, B vitamins, folate, zinc,
• Good quality cuts of meat, poultry and fish for protein, iron, vitamin B12, selenium, iodine (fish),
• Or, combine wholegrains and beans or legumes for a full complement of amino acids, zinc, potassium
• Limit sugary treats (easier said than done for lots of us but as long as you’re getting enough essential nutrients from a wide variety of natural foods).

A healthy balanced diet means for a healthy balanced body and a healthy balanced mind…clichéd this may be but it is still true‼