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How to eat a low carb diet

Rachel Lett, RNutr.

Chief Care Officer

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Have you heard the great news? Nutritional ketosis is standing in the spotlight for its therapeutic effect to reverse insulin resistance and improve overall health 🙌

The evidence is there, it’s strong and it’s mounting. To catch up on this topic, check last week’s article where I discuss the details of this metabolic state.

Today I want to explain how to change your diet, so you can retrain your metabolism and reap the benefits of nutritional ketosis.

In no time, your health will skyrocket and eventually, you’ll feel like a superhuman 🚀

More specifically, I will be focusing on macronutrients—major components of the diet which provide energy to power our bodies.

These are fat, protein and carbohydrates, each of which are composed of smaller units that we need for development and maintenance. Some of these units can be synthesised in the body, whilst others are essential and need to be obtained from the diet.

By altering our energy source from fat, protein and carbohydrate, we can maximise nutrition and optimise health.

Turning the western diet on its head, nutritional ketosis is achieved through a well-formulated diet of high fat, low carbohydrate and moderate protein to meet your body’s needs.

A far cry from standard, nutrition guidelines, it’s no wonder the health of our nation is swiftly nose-diving into a pool of diabetes, cardiovascular disease, cancer and obesity since we have implemented them 🤔

To the expense of our health, policy and guidelines are slow to change, even when the body of science supporting a diet high in fat, and low in carbohydrate is so compelling for type 2 diabetes.

You are one of the lucky ones. You have taken the steps to expose yourself to powerful research and information that is committed to your health and wellbeing 🤓

Let’s break this down

A diet of 60–85% fat, 15–30% protein, and 4–10% carbohydrate will promote nutritional ketosis.

Coined by Dr. Stephen Phinney and Dr. Jeff Volek, nutritional ketosis is defined as having a blood βHB ketone level of > 0.5 mmol/l.
However, the sweet spot for therapeutic effect is seen at

By carefully adjusting our macronutrient intake, we can reduce blood sugar levels and increase ketones. Eating a diet that is more than 60% fat goes against what you have been conditioned to believe as “healthy”.

The task at hand will be to reject out-dated recommendations, and embrace a new way of eating that will improve your health, based on the latest medical science.

This won’t happen overnight. You might be challenged by the food industry, Public Health and even your friends, encouraging you to eat a varied diet including “healthy whole grains”, and declaring “fat is bad”.

Hold on tight. Take time to learn the science, test blood glucose and ketones: a great way to understand where your health is at and why — we’ll be here along your journey to provide you with the right tools to do so.

As your health begins to shine, these challenges will fade away.

Understanding your new macronutrient ratio will help you prepare for this shift in mindset 💪

Let’s begin with our favourite, fat!

Get to know your macronutrients

Fat is your new best friend — it accounts for 60–85% of your new diet. Our society has been conditioned to ‘fat phobia’; so being comfortable with eating this much fat will be one of the biggest hurdles to overcome.

Fat does not make you fat

The combination of carbohydrate and fat is what makes people gain weight: there is a web of hormonal mecanisms and pathways involved.

If we consume carbohydrate, our body will use it as a primary fuel source. At the same time, a spike in insulin levels signals the body to store fat as an energy reserve.

This was an important mechanism for our ancestors who would gorge on summer berries in preparation for a meagre, cold winter. Nowadays, this mechanism is exploited, as we “lay down” fat reserves all year long.

Undoubtedly, disparaging thoughts that “fat is unhealthy” will still creep in, but give it time. Trust me, improved health will soon follow, and you will be able to embrace and enjoy fats without that nagging guilt.

In the meantime, take comfort in knowing that unlike carbohydrates, fatty acids are essential (i.e. our body can’t synthesise them so we need to get them from diet), and without them, we’d be stuffed!

This nutrient dense food is integral for cell membrane structure, synthesising sex hormones, absorption of fat-soluble vitamins, communication of the central nervous system, optimising digestion, regulating cholesterol levels and helps stabilise blood sugar levels.

Also not to mention how delicious and satisfying they are 😋

But hold up, not all fats are equal

It is important to carefully choose the type of fat you eat. There are four different types — saturated fats, monounsaturated fats, (MUFA’S) polyunsaturated fats (PUFA’s) and trans fats.

Saturated fat is the most stable and less likely to oxidise or go rancid.

Relish all the saturated fat found in fatty meat, fish, cream, cheese, coconut oil, cocoa butter, avocado, butter, ghee and lard. If possible, try to source high quality, organic, grass-fed products to reduce the toxic load of herbicides, chemicals and antibiotics, which is stored in animal fat.

Use ghee and coconut oil over plant-based oils for cooking, as these are heat stable and won’t readily oxidise.

Focus on including plenty of monounsaturated fats, too. These are found in extra virgin olive oil, avocado and macadamia oil, goose fat and lard. Again, choose organic, cold pressed and unrefined and use liberally for dressings and dips.

Polyunsaturated fats are very unstable so should only be eaten cold, and never heated or refined (sunflower oil and rapeseed oil are usually processed in this way) — oxidised fats can cause inflammation in the body. PUFA’s, including omega 3 and omega 6, play an integral role in health and wellbeing.

The trick is getting the balance right. Ideally, the ratio of omega 3 to omega 6 should be 1:1, however, this is more like 1:30 for the average western diet. Good sources of omega 3 include flaxseed, oily fish, hemp, walnuts, chia seeds, nut oils, sesame oil and avocado oil.

It’s also worth noting that grass fed, organic meat has a better ratio of omega 3 to omega 6 compared with grain fed animals.

Trans fats have got a bad name for themselves, and with good reason too. The chemically altered, hydrogenated vegetable oil is toxic to health and should be avoided at all costs.

However, the naturally occurring trans fat (vaccenic acid), found in grass-fed meat and dairy products shouldn’t induce a frenzy of panic and high blood pressure — it’s fine.

Steer clear of trans fat found in margarine, butter replacement, vegetable oils, shortenings, and processed food in general.


The requirement is calculated as 1 gram of protein per kilogram of lean body mass (LBM) — don’t worry, we will do the maths for you!

Protein requires a watchful eye — too little and growth and repair will be compromised, but too much and you will be kicked out of ketosis since excess protein is shuttled into gluconeogenesis.

With so many delicious, protein-rich foods on the ketogenic menu, it can be easy to overindulge, so try to be mindful of how much steak you should be eating.


Their limit will vary for each individual, and be prepared for it to change over time as you become more insulin sensitive and fat adapted. As a general rule of thumb, net carbs are between 10–50 grams per day, or 4–10% of your daily calorie intake.

In the beginning, familiarise yourself with low carb food that you can eat, and pay attention to ketone and glucose levels. Our team will help you find suitable foods that promote nutritional ketosis.

People often associate carbohydrates with sugary and starchy food like fruit, cake, grains, pasta, potatoes and quinoa. However, carbohydrates are present in many ‘non-typical’ foods such as milk, root vegetables, squashes, cashew nuts, soy sauce and balsamic vinegar.

Read nutrition labels carefully and be mindful of unassuming products — you’d be surprised by how much carbohydrate can sneak into food. Refer to the “foods to include” (a post we’ll publish next week), and try to choose low-net carb foods that are high in fiber 🥬

Drench your vegetables with delicious fats. This makes them irresistible and also reduces the glycaemic load.

Dealing with family and friends

Acknowledge that it will take time to adapt to this new way of eating. You have been exposed to a lifetime of nutritional guidelines, enforcing a high carbohydrate, low-fat diet; so you will certainly have to tackle food demons and mental blocks about fat.

I can assure you that embracing nutritional ketosis, you will be free from the grip of carbs and develop a positive relationship with food. It just takes time, trial and error, to learn and design a sustainable lifestyle that works for you.

When it comes to chronic health, you’re the scientist 👩‍🔬👨‍🔬

Looking forward to my next post? 🤩

I’ll be revealing all the wonderful food you can eat, and how to build a good relationship with food.

If you’re interested in joining Span, download our mobile app on www.span.healthor contact us at to learn more.

Ciao 🙌🏽

I’m sure you’re curious about the science behind all this 🔬 Here are some recent medical publications about this topic:

And some fantastic books:

  • The Art and Science of Low Carbohydrate Living: An Expert Guide to Making the Life-Saving Benefits of Carbohydrate Restriction Sustainable and Enjoyable, by Jeff S. Volek PhD RD & Stephen D. Phinney MD PhD
  • Nourishing Fats: Why We Need Animal Fats for Health and Happiness Paperback, by Sally Fallon Morell

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