Nutrition basics for beginners explained by professionals

What will you learn from this article (a 15 minute read):

In order to be successful at anything, you need to have an understanding of the subject (and of course it helps if you have an interest in it too).  The subject of nutrition is no different, but with everyone from social media influencers to weight loss ‘gurus’ chiming in with their opinions, many of which have no basis in science, it can be confusing to know what is true and what is nonsense.
If you want to succeed at your body composition goals, whether that means losing fat, gaining muscle or even just making sure you are fueling your body properly for a healthy life, you will need to know the answer to questions such as, “What should I eat?”, “How much should I eat?” and “When/how many times a day should I eat?”
At ATP Personal Training , we help clients learn the answers to those questions and many more.  Read on to learn what nutrition means and how you can build your own plan in line with your own individual goals.
Nutrition is a vast subject, a rabbit hole that you can go down and become completely lost.  Our first piece of advice is: keep it simple.  The more straightforward your approach (and this actually goes for anything), the easier it will be for you to follow and the less likely you will be to give up.
What will teach you more about nutrition than anything else is your own experience; for you to follow a certain approach for an extended period of time and note how you feel, how you sleep, what your mood is like and how you perform at work and at the gym.  But how many different approaches are there?  Should you start with High carb or low carb?  What about insulin?  And what about your macros?
For the uninitiated, ‘macros’, or macronutrients, are the nutrients that we need in more substantial quantities; in other words protein, carbohydrates and fat. We’ll go through each in more detail but when it comes to fat loss, muscle gain or even maintaining your weight, macros and their ratios actually come second in importance. The infographic below shows a pyramid of nutritional priorities for success, regardless of your nutrition goal:

Calories and Energy Balance

You may have memories of your parents or even grandparents ‘going on a diet’ and counting their calories, which are the units of energy contained in food.  As old fashioned as it sounds, they were on to something!  Simply put:

  • If you want to lose weight you must burn more calories than you consume.
  • If you want to gain weight then you must consume more calories than you burn.
There are no “what ifs” or “buts” here.  If someone tells you they are eating fewer calories than they are burning but they aren’t losing weight then they are either eating more than they think or burning less than they think.  Unfortunately it takes more than one spin class to burn off the calories from 4 hours of champagne brunch, as much as we all wish that wasn’t the case.
There are various ways to estimate how many calories your body needs to maintain, lose or gain weight, but ultimately the most important take-home here is to understand that CICO (calories in, calories out) dictates your outcome.  If you want to eat cake and lose weight then you can do so, but you will need to increase your activity level to a point that might make you think twice about a second helping…
Another acronym beloved by the fitness industry is NEAT. NEAT stands for Non-Exercise Activity Thermogenesis and it refers to the calories you burn often without even realising. Fidgeting, walking to the bathroom, gardening and cleaning the house would all count as NEAT.
With this in mind you can see that a person who is very sedentary (taxi to work, desk job for 8 hours, taxi home, evenings in front of the TV with takeaway food) would burn far fewer calories through NEAT than a more active person (habitually walks or cycles to work, works for example as a waiter or waitress on their feet all day, stands up to cook for the family when home and maybe only sits down for an hour or two in the evenings).

Increasing your NEAT through healthy habits such as walking to work or always taking the stairs instead of the elevator is a great way to burn more calories during the day, every single day.  Many of our clients also claim it’s the secret weapon to sustaining their fat loss and cementing their healthy habits.


With the exception of water, everything that we consume is a combination of one or more of the 3 macronutrients.  In fact, very few foods contain only one.  We generally classify foods as a specific macronutrient type based on the one that contributes the most calories to the overall calorific value of that food.  Here are some examples:

Chicken breast
Classification – protein
Trace nutrient – fat

Sweet potato
Classification – carbohydrate
Trace nutrient – protein

Streaky Bacon
Classification – fat
Secondary classification – protein
Trace nutrient – carbs

Now let’s briefly look at each macro in more detail:


  • Maintaining energy balance and consuming adequate protein are the 2 main goals of any good nutrition plan
  • Each gram of protein contains 4 kcal*
  • Proteins are collections of amino acids. Each amino acid plays a different role in the body.
  • If you talk about 100g of protein, that does not mean 100g of chicken breast. 100g of chicken breast contains about 25g protein, in addition to water, fat, trace minerals etc.
  • There are lean proteins (including skinless chicken breast, white fish, egg whites) and fatty proteins (such as oily fish, lamb, pork belly etc)
  • Plant-based protein sources such as tofu and soy products are often not as easily absorbed by the body as animal proteins


  • Each gram of fat contains 9kcal* (more than double protein and carbs which is why even ‘good’ fats such as avocado or olive oil can quickly inflate our total calories for the day)
  • Dietary fat is the most energy-rich food source available. The body breaks down fat into fatty acids.
  • Like protein, some fats are essential for optimal health
  • Sources include: nuts, avocado, olives, dark chocolate, butter, coconut oil, cheese, fatty meat


  • Each gram of carbohydrate contains 4kcal*
  • ‘Carbohydrate’ covers an extremely broad category, but there are 2 main types; complex carbohydrates (starches), found in foods like bread, rice, pasta and potatoes, and simple carbohydrates (sugars), which includes the naturally occurring sugars in fruit and dairy products as well as the kind of sugar we spoon into our coffee or that is added to foods and soft drinks)
  • Although in the modern diet they make up the bulk of many people’s energy consumption, carbs are not actually essential for the physiological function of the body (amino acids and fatty acids are)
  • Carbohydrates provide micronutrients, phytonutrients (a beneficial nutrient found in plants) and fibre

*Note: we talk about calories, but technically we should be referring to kilocalories or kCal. Everyone uses these interchangeably, but when you see 100kCal on food packaging or in a macros listing it means 100 calories in laymans’ terms.

A word about alcohol…

Although many of us enjoy an alcoholic drink from time to time, most of us are aware that it isn’t exactly good for us.  At ATP Personal Training we have many clients who successfully abstain from alcohol while making their initial lifestyle and healthy habit changes, but in most cases they are unlikely to stop drinking forever.
Indeed, alcohol plays a key role in many of our special occasions and business functions and, unless your peers are aware that you don’t drink for religious reasons, you might be on the receiving end of a raised eyebrow or two if you politely decline a glass of champagne or announce that you have decided to become teetotal. Read how alcohol affects your fitness here.
  • Alcohol is sometimes referred to as the 4th macronutrient (even though it has no nutritional value and can even promote poor nutrition due to its toxic effect on the digestive tract)
  • Alcohol has 7 kcal per gram
  • Although it is possible to make progress towards your body composition goals if you include alcohol in your diet, it is not recommended due to the negative effects
  • Negative effects include but are not limited to: poor sleep, increased hunger, slower fat loss, reduction in performance and feelings of guilt the next day due to depleted serotonin levels

In summary: Protein and Carbs = 4 KCal per gram, Fat = 9KCal per gram and Alcohol = 7KCal per gram


Micronutrients can be categorised into either vitamins or minerals. Vitamins and minerals play some critical roles within the body including normalising bodily functions, energy metabolism, immune function, antioxidant supply, bone growth, muscle contraction and much more.
Micronutrient deficiencies, ie the levels in your body and diet are low, mean that your body doesn’t have enough raw materials to carry out normal bodily functions and therefore deficiencies will lead to poor performance, slower recovery, sickness and even diseases. All of these situations would be detrimental to fat loss as well as general health. Consequently, you can say that a person with any form of nutrient deficiency would have a more difficult time losing fat.

Vitamins and minerals can be categorised into 4 main groups; water-soluble vitamins, fat-soluble vitamins, macrominerals and trace minerals.  We will not go into detail about each type of micronutrient here, but the tables below will give you an idea of which kinds of food you can eat in order to ensure you are getting them in your diet:

Water soluble vitamins

  • B1: ham, soy milk, watermelon
  • B2: milk, yoghurt, cheese, fortified cereals, whole grains
  • B3: meat, poultry, fish, mushrooms, potatoes, whole grains
  • B5: wholegrains, chicken, broccoli, mushrooms, avocados
  • B6: meat, fish, poultry, legumes, soy products, bananas
  • B7: eggs, fish, soybeans, whole grains
  • B9: asparagus, spinach, fortified grains and cereals, chickpeas, orange juice
  • B12: Meat, poultry, fish, milk, cheese, fortified cereals, soy milk
  • Vitamin C: citrus fruit, broccoli, potatoes, brussels sprouts, tomatoes, strawberries, spinach

Fat soluble vitamins

  • Vitamin A: beef, liver, eggs, prawns, fish, sweet potatoes, carrots, pumpkins, mangoes, spinach
  • Vitamin D: oily fish, fortified cereals
  • Vitamin E: vegetable oils, whole grains, leafy green vegetables, nuts, whole grains
  • Vitamin K: Cabbage, eggs, milk, spinach, broccoli, kale


  • Calcium: yogurt, cheese, milk, salmon, leafy greens
  • Chloride: salt
  • Magnesium: spinach, broccoli, seeds, legumes, wholewheat bread
  • Potassium: meat, milk, fruit, vegetables, grains, legumes
  • Sodium: salt, soy sauce, vegetables

Trace minerals

  • Chromium: meat, poultry, fish, nuts, cheese
  • Copper: shellfish, nuts, beans, prunes, whole grain products
  • Fluoride: fish, tea
  • Iodine: seafood, iodised salt
  • Iron: red meat, poultry, eggs, fruits, green vegetables, fortified bread
  • Manganese: nuts, legumes, whole grains, tea
  • Selenium: organ meat, seafood, brazil nuts, walnuts
  • Zinc: meat, shellfish, legumes, whole grains

Hydration (water)

Our bodies (which are more than 50% water) cannot perform properly if we do not drink enough water.  Our systems need the lubrication water provides for all kinds of functions and processes, including these:
All nutrient transport around our bodies occurs in water, be it electrolytes to muscles or waste products out of muscles. We need to be properly hydrated for our digestive system to function properly; to pass urine and faeces out of our bodies.
Without sufficient water, the cartilage at the end of joints is exposed to more wear and tear, resulting in painful conditions such as arthritis.
When we are too hot, we sweat to cool down.  If we are not sufficiently hydrated, this process will be hindered.
We need water in order to absorb the water-soluble nutrients mentioned in the previous section.  Water itself should also be a source of minerals, but much of the water accessible to us is either distilled (stripped of minerals) or full of chemicals.

How much water is the right amount?

Traditionally, water recommendations were based on body weight (40ml of water per kg of body weight).  However, bear in mind that this figure does not take into account how much lean body mass someone has (the more lean mass you have, the more water you will need), not does it account for activity levels, the climate you live in or how much any one individual sweats in a day (we are all different).

General rules for water consumption can be summed up below:

  • Try to drink at least 40ml per kg of bodyweight per day (more if you exercise or have a lot of muscle)
  • Don’t drink much with meals as too much liquid can dilute your stomach acids and actually hinder digestion
  • Keep a water bottle with you at all times so you can sip throughout the day rather than trying to drink your daily quota when you remember at night (which will interfere with your sleep as you will wake in the night with a full bladder)

Nutrient timing

Looking back at our pyramid of nutritional priorities, nutrient timing falls very close to being the icing on the cake, that is, you should make sure that you are doing the basics well and without stress before you worry about whether 4 meals a day is better than 3 or at what time you should have your breakfast for optimal benefit.
The truth is, in terms of body composition, and if calories and macros are equal, there is almost no physiological difference, no matter how many meals you want to eat.  Eating more times per day does not ‘fire up your metabolism’, even if your favourite influencer tells you the opposite.

Questions you should ask yourself might be:

  • How many times can I realistically cook each day?
  • What size meal do I need in order to feel satisfied and not crave snacks?

Your answers to these questions might help dictate the optimal number of meals for you.

For most of our clients, we would recommend starting with 3 meals per day, in part because this is what most people are used to so it keeps things simple and encourages adherence.  The best plan (workout or nutrition) is always going to be the one that you can stick to.


In an ideal world supplements should not be a shortcut to optimal health.  As the name suggests, they should only be used when you are unable to get a certain nutrient from your diet.  In many cases, you can boost your levels of certain micronutrients by making changes to what you eat, for example adding fermented foods, grass fed and pastured meat or regeneratively farmed vegetables that have higher mineral and vitamin levels.

However, more chemical use in agriculture, degradation of soil quality and therefore of food quality and poor lifestyles (lack of sleep, high stress levels, insulin resistance etc) mean that sometimes it can be difficult to achieve optimal nutrition just from our food and drink.
The supplement industry is enormous and most supplements do not even work.  Labels are confusing (and in some cases manufacturers don’t even have to list all ingredients). This allows cheap fillers to bulk up products that are already of questionable quality, and it can be very hard to find a brand you can trust.
We only recommend supplements that we trust to clients, and those that are backed by science. Here are our top 5, in no particular order with links to Proteus Nutrition where relevant (the manufacturer we use and trust):
  1. Protein powder – to maximise essential amino acids and fill any gaps in protein consumption. Many people opt for a shake after training in order to consume protein when they don’t feel like a full meal.  It’s also a convenient way to boost protein without overdoing fat and carbs.
  2. Electrolytes – sodium, magnesium and potassium – to maximise hydration. People are aware that too much sodium is harmful, but in fact too little sodium is even more so.
  3. Essential Fatty Acids (EPA/ DHA) – to improve general health. These are commonly known as Omega-3 oils and they occur predominantly in seafood, so unless you eat oily, deep sea fish daily you probably don’t get enough.
  4. Vitamin D3 (with K2) – to improve general health (* note supplementing vitamin D is no substitute for sun exposure, but might be necessary if you don’t get much sun or if you’re overweight).
  5. Magnesium – for overall health and energy. Most people are slightly deficient in magnesium, yet it is responsible for over 300 different processes within the body.

Building a simple nutrition plan

If you’ve got this far, you now have a more comprehensive understanding than most of general nutrition and what your body needs.  But how do you translate that into a meal plan that you can use in order to hit your weight loss or muscle building goals?  We’ve put together a short step by step guide to help:
  1. Set your daily calorie amount. There are various online calculators that can help you work this out. Even if your goal is to lose weight, we would recommend starting off at your estimated maintenance calories so you can get used to tracking and eating what might be more protein than you are used to.
  2. Work out how much protein you need. A good starting point is to set your protein to at least 1.8g per kg of bodyweight, so a 70kg person should be looking at eating at least 126g per day. If you are working out consistently we usually recommend slightly more than this at 2-2.4g per kg of body weight daily. Vegetarians and vegans should aim much higher due to the lower bioavailability of plant-based protein sources
  3. Work out how much fat you need – aim for 30-40% of your total daily calories. As you know, fat has 9 kcal per gram, so if your daily calories are set at 1800, then your fat goal would be (40% of 1800) divided by 9 = 80g of fat per day.
  4. Take the protein calories and fat calories away from your daily total and divide what is left by 4. That’s your daily carbohydrate number. In our example with the 70kg person and the 1800kcal allowance, they are getting 126g protein x 4 = 504kcal from protein and 80g fat x 9 = 720kcal from fat, which is a total of 1224 calories. That leaves 576 calories for carbs, which when we divide by 4 gives us 144g.
  5. Decide how many meals per day you will eat. We would recommend 2-4, depending on your current patterns.
  6. Try to distribute your daily protein amount evenly between each meal for better digestion and utilisation by your body.
  7. Try to keep both fat and carbohydrate consumption fairly low directly after a workout

When it comes to choosing foods that you enjoy, bear in mind that sometimes you might need to make small sacrifices or substitutes in order to reach your goals. At ATP Personal training we help clients like you navigate meal options, as well as teaching you all the tips you need in order to cement healthy habits into your life.

Note: this article is based on education elements from the ATP Personal Training Coach Curriculum