What is the ketogenic diet? The ultimate guide to keto.

When you go on a healthy eating plan, you couldn’t expect to see butter, cream and cheese on the allowed list, would you? Normally these high fat foods are feared and snatched out of people’s hands, but not on the ketogenic diet. No, it’s quite the opposite. 

The ketogenic diet has skyrocketed in popularity in the last year or two and Kim Kardashian, Megan Fox and Vanessa Hudgens all swear by it.

But what exactly is it? Can you actually have unlimited butter? Let’s take a look.

What is a ketogenic diet?

The ketogenic diet, also known as ‘the keto diet’ is an eating plan very low in carbohydrates, and very high in fat. It’s nothing new and has been used clinically for many years, traditionally to treat epilepsy and manage seizures.

However, the diet has recently come into the spotlight, particularly because of what occurs when you put your body into ketosis.

Image: Unsplash.

What is ketosis?

Eating very few carbohydrates will put your body into a state called ketosis. The main source of energy for the body to function is usually carbohydrate and when these carb stores are not available, your body switches to burning fat, resulting in the production of ketone bodies by the liver.

The result of ketosis is enhanced burning of fat stores and relatively quick weight loss, particularly when compared to traditional low calorie diets. 

Is ketosis safe?

In most cases, yes. There is no clinical evidence to indicate the ketogenic diet is dangerous. Studies have found that when abiding by the guidelines, the eating plan was more effective than a traditional low kilojoule style of diet.  

These studies were conducted over a six month time period, and results were of most significance in obese patients. There is a need for further research to be conducted over a longer time period. 

However, this approach is not free from side effects. Symptoms you may experience in the initial first days include fatigue, nausea, headaches and bad breath.


These often pass after a week or so, but everyone’s experience is slightly different. The diet is also likely to lack key nutrients like fibre, vitamin B and calcium, so supplementation may need to be considered. 

You may also find the diet could affect gut health or metabolism, so it's important you only undertake the diet with guidance of a health professional.

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What do and don't you eat on the ketogenic diet?

Ketogenic diets contain roughly 15 percent carbohydrate and up to 75 percent fat, leaving the remaining 15 percent for protein. This low carb level equates to be approximately 20 to 30grams a day, which is roughly the equivalent of one slice of bread and maybe a sprinkle of muesli, but just a sprinkle. When you compare this to a general healthy diet, the distribution of macronutrients is much more evenly spread, at roughly 30 to 40 percent carbohydrate and 20 to 30 percent fat. 

In order to reach this high daily target for fat, foods such as nuts, cheese, butter and meats are subbed in to replace carbs in the diet. For example, your meal plan might include;

  • Breakfast: Scrambled eggs with bacon, grilled mushroom and tomato
  • Lunch: Pesto chicken with steamed zucchini and cauliflower
  • Dinner: Rib-eye steak with greens and avocado
  • Snacks: Boiled eggs, nuts, olives, deli meats and canned tuna

It’s important to remember that ketosis is a very fragile state, so the total carbs you eat must to be kept extremely low, and if you have too much, you'll quickly jeopardise any benefit of the diet.


For example, even if you follow the requirements all day, a sneaky few squares of chocolate or handful of rice crackers will push you out of ketosis if your total intake of carbs goes above the limit of roughly 30 grams for the day.

Image: Unsplash.

So, should you do the ketogenic diet?

If you do have a significant amount of weight to lose it might be worth considering. However, the hardest thing about the ketogenic diet, just like any diet, is sticking to it.

The keto diet will work if you follow it. But unfortunately, most find it harder to maintain than other restricted eating plans. Most don’t do it properly to get the best results, or they can't maintain the severe carbohydrate restriction for enough time to achieve the results they desire. 

When you go keto, you say goodbye to whole grains, bread, fruit, starchy vegetables and sugar for a long period of time. As a result, it can be particularly difficult to adapt the diet to social settings, eating out and travelling.

Ultimately, it’s always a good idea to cut down on processed foods, particularly those high in refined sugar, fat and salt, but there is a lot more to consider when undertaking the ketogenic diet. 

Given the strict carbohydrate limit and need for ongoing monitoring, it is important to consult an Accredited Practising Dietitian or doctor before commencing the diet. Strict ketogenic diets should only be followed under medical supervision.

Rachel Scoular is a Dietitian & Nutritionist. You can learn more about her by visiting her website

Have you tried the ketogenic diet before? Did you find it worked for you?