Understanding the science behind food

Understanding the science behind food


With constantly changing information about what and how we should be eating, It’s time to understand how our bodies are built and fuelled by food. 


Protein: the building blocks

Protein is made up of amino acids, which are often referred to as the body’s building blocks. Our bodies aren’t able to produce all of these naturally, which means we need to source these ‘essential amino acids’ from food, in roughly the
correct proportions, to remain healthy. Protein is vital to our wellbeing, as it can be found in neurotransmitters (like serotonin and dopamine), hormones (like insulin), cells, enzymes, muscles and even our bones.

How does it work? 

Our bodies break down proteins into amino acids and then use them to build new proteins for important functions, such as transporting biological molecules throughout the body and promoting communication between different cells.
We often associate protein with athletes and body-builders due to its crucial role in muscle-building and healing. It’s a
a common misconception that exercising and lifting weights strengthen and build muscles – in fact, the opposite is true.
Working out causes breaks and tears in the muscles; it’s protein that heals them and creates more muscle mass post-exercise.

How much do you need? 

In their book The Hybrid Diet (Piatkus), nutrition experts Patrick Holford and Jerome Burne recommend eating around either 15g of protein three times a day, or 25g twice a day, noting that it should form about 10-15% of your total caloric intake – visually, this should take up about one-quarter of your plate. They add, however, that the amount of protein you require depends on the amount and type of exercise you do and what you hope to achieve with your body. While
endurance athletes should be eating 1.2-1.4g of protein per kilogram of body mass daily, strength athletes require 1.2-1.7g of protein per kilogram.

What happens if you don’t get enough? 

Protein deficiency over a prolonged period can lead to:

  • Infections, due to inadequate protein to help the immune system function optimally.
  • Weaker, wasted, cramping muscles, which are unable to grow and repair themselves. Very low dietary protein can also result in the body using muscle tissue as fuel to support vital functions, resulting in eventual atrophy.
  • Inability to heal and accelerated ageing, as our skin requires collagen to remain healthy.

What happens if it gets too much? 

Too much protein can have serious health consequences, including raised insulin, problems with kidney function and a heightened risk of cancer.

Which foods are good protein sources? 

There are various foods that provide protein, including meat, fish and vegetables. However, some are better than others, especially if you’re watching your weight or are trying to optimise your hard-earned gym results. The best sources of dietary protein include:


While meat in general is protein-rich, red meat also tends to be high in saturated fat, densely caloric and is linked to heart disease. Processed pork products are often also problematic, as they’re generally high in salt and nitrates. This is where chicken stands above the rest: it’s a great source of protein and has just the right amount of calories to form the basis of a meal, without being so high that it can’t be paired with a few delicious sides. There’s a reason chicken breasts are the go-to meal for athletes and gym bunnies!


This powerhouse protein source is ideal for replenishing muscles and providing the building blocks your body needs to stay fit and healthy. Eggs contain around 6g of high-quality protein and are the golden standard by which other foods are measured. They also contain all the essential amino acids our bodies are unable to provide for themselves, as well as vitamins K, A and E, and a range of B vitamins.


While eggs and meat are considered high-quality protein, as they contain the correct amino acid balance, there’s protein to be found in leafy greens like spinach and kale, flowering varieties like broccoli and cauliflower, mushrooms, various beans and peas.


Carbohydrates: the fuel

Much-maligned by many diets, carbs are the starches, sugars and fibres found in fruit, vegetables, grains and milk products. Although they’ve been given a bad rap, carbs are the body’s main source of energy – they allow your body to create glucose, the fuel used to power your brain and muscles. Carbs can generally be split into two varieties: simple or complex, based on their chemical make-up:

  • Simple carbs are made up of basic sugars, which are easily digestible. These can be naturally occurring, processed or refined – the last two are often added to baked goods like cakes, fizzy cooldrinks and sweets.
  • Complex carbs can be found in wholegrains, starchy vegetables and legumes. These carbs are comprised of longer chains of sugar molecules, which take longer for the body to break down and use, providing a more consistent and sustained energy release.

How do they work? 

Carbs are broken down by the body and converted to glucose, which is absorbed into the bloodstream. In response to higher sugar levels, the pancreas releases the hormone insulin, which is necessary to transport sugar to the cells
where it can be used to create energy.

How much do you need? 

Most dietary guidelines recommend that just over one-third of your diet should be comprised of starchy (complex) carbohydrate-rich foods like rice, bread and potatoes, with another one-third being made up of naturally occurring (simple) carbs from fruit and vegetables. More than half your daily caloric intake, then, should be made up of carbs.

What happens if you don’t get enough? 

Cutting carbs may be common while following certain diets, but it could have negative consequences:

  • Energy slumps. Carbs are converted into glucose, which in turn is converted into energy, so a body deprived of carbs will also be deprived of energy. Glucose also acts as fuel for the brain and without it, you may find it more difficult to concentrate and feel mentally sluggish.
  • Digestive troubles. Fibre, one of the types of carbohydrates, helps keep constipation at bay and also lowers the risk of conditions like diverticulosis by preventing blockages in the digestive system.

What happens if you get too many? 

Eating too many carbs, especially as processed and refined sugars, can have a variety of unpleasant effects, including unwanted weight gain, sugar cravings, feeling low on energy, and mood swings.

Which foods are good carbohydrate sources? 

Stick to healthy carb sources for longerlasting energy, avoiding overly sugary options. Foods which can provide a slower, more consistent energy release and avoid potentially harmful spikes in insulin levels include:


Oats are packed with fibre, protein and nutrients, and have been shown to lower cholesterol and blood sugar levels. Avoid sugar-packed, flavoured instant varieties and opt for plain or rolled oats instead.

Sweet potatoes 

These delicious veggies are a great source of vitamins and antioxidants and act as a natural anti-inflammatory.


Bananas contain pectin and resistant starch, which research has found may moderate blood sugar levels and help you feel fuller for longer. They’re also high in nutrients essential for good health, including magnesium and potassium, and act as powerful antioxidants.


The information on these pages is not intended to be a substitute for professional advice, diagnosis and treatment. Always consult your GP or a doctor for specific information regarding your health.


About Caitlin Geng

Your Family’s Content Editor, and a real word nerd who loves reading and writing. She was recently married, in 2018, and is a ‘mom’ to two loveable pugs. Caitlin received 3rd place in the ‘Galliova Up and Coming Food/Health Writer of the Year’ category in 2019!


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