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The Healf Source
Is Keto Making A Comeback?
Written by: Natalie Louise Burrows
Written on: April 6, 2025
In recent years, the ketogenic diet has surged in popularity, but do you really know what it entails? Often shrouded in misconception and hype, this dietary approach has a fascinating history and science behind it.
What exactly is a ketogenic diet, and what principles guide this unique nutritional strategy? How did it evolve from a medical treatment to a mainstream weight loss trend? More importantly, what potential benefits and risks should you be aware of before considering this approach?
In this article, Caroline Roberts, a nutritional therapist and health coach at Integral Wellness, an online nutrition and health clinic, will demystify the ketogenic diet, giving you a balanced view of this controversial dietary approach that is gaining popularity once again.
Where did the keto diet originate?
Fasting was the precursor to the ketogenic diet, which was used to reduce seizure severity in 20 children and adults in 1911. By 1921, it was documented that cognition and the control of epileptic seizures had improved with fasting because of a shift from carbohydrate to fat metabolism.
Why? Ketone bodies acetone and beta-hydroxbutyric acid were present during fasting and when there was a very low proportion of carbohydrates with a high proportion of fat. It was theorised that ketonemia, the presence of ketone bodies in the blood as a result of the body burning fat for fuel, could be achieved with a low carbohydrate diet rather than starvation.
And so, the ketogenic diet (KD) was born.
How does the keto diet work?
The ketogenic diet, or "keto" for short, is a way of eating that changes how your body gets energy. Here's a simple breakdown of how it works in the body:
- The body favours carbohydrates as its primary fuel source; it is easy to digest and convert to glucose quickly.
- Insulin is needed to move glucose into cells to make energy.
- Where there is reduced availability of carbohydrates, there is a lowering of insulin, which you might think will leave you energy-depleted, but stored glucose in your muscles and liver can be released to make up the shortfall.
- After 3-4 days of very little carbohydrate intake, 10-15g/day, you will run out of stored glucose, and your body will need to turn to fat stores.
- Fat is broken down into free fatty acids, the raw materials for the liver to produce ketones .
- These ketones fuel your body and brain, just like sugar usually would. This process is called ketosis.
Even if you're not on a keto diet, your body can use some ketones for energy when carbs are low. This shows how flexible our bodies can be when using different energy sources.
Keto diet 101
In real life, there are multiple variations of what is considered a ketogenic diet.
The ketogenic diet isn't one-size-fits-all, and current general guidelines are:
- Carbohydrate restriction - typically 20-50g daily (less than 10% of total energy). For perspective, an apple contains roughly 20g of carbs.
- Protein intake - usually 1.2-1.5g per kg of body weight.
- Fat consumption - the remaining energy needs, often 60-90% of total intake.
The original balance of macronutrients for drug-resistant epilepsy in children, the classic ketogenic diet (cKD), is 4g of fat for every 1g protein and carbohydrate. 80-90% of calories from fat, 6-8% from protein, and 2-4% from carbohydrates.
It’s important to appreciate that although these guidelines are based on research, individual needs and ketone production vary among individuals. Practical applications of the diet - because it’s not necessarily easy - may differ based on personal goals and metabolic responses. The majority of research about the keto diet is based on drug-resistant epilepsy and not the general population.
Should you try the keto diet?
The typical Western diet relies heavily on carbohydrates, particularly easily digestible sources like cereals, bread, pasta, and potatoes. Adopting a ketogenic diet represents a significant change in eating habits. It requires a fundamental shift in food choices, a new approach to meal planning, and time for your body to adapt metabolically.
This transition can be challenging, both mentally and physically. It's important to approach the change gradually and allow your body sufficient time to adjust to its new fuel source.
Like most diets, the Keto Diet has fallen in and out of ‘fashion’ and for fair reasons. Initial side effects make it likely that most people would stop within the first few days. Adherence to a strict KD is difficult to sustain, and the results of longer-term strict adherence are not greater than other dietary approaches, with similar results within 12–24 months.
But what about the health benefits?
Why might the ketogenic diet be good for your health?
The ketogenic diet (KD) has gained significant attention in recent years as a potential therapeutic approach for various health conditions, particularly type 2 diabetes and obesity. However, as research continues to unfold, a complex picture emerges, revealing both promising benefits and potential risks.
- Most “Keto Flu” symptoms are temporary for the first 1-4 days, as the body adjusts to ketosis. Replacing loss of sodium through urine is essential to avoid this.
- In the short-term, the first 6 months, a KD outperforms low-fat diets for weight loss.
- Some studies show that a KD can lower HbA1c levels.
- Lipid profiles trend towards improved cardiovascular health but the type of fat consumed will influence lipid profile - good fats such as avocado, nuts, seeds, olives will more likely result in a favourable lipid profile compared to fats such as processed meats.
- Keto is associated with decreased inflammation markers.
- Potential for blood pressure reduction.
- Beta-hydroxybutyrate (BHB) ketone bodies may support gut health.
- A well-planned KD with a diverse range of foods can be nutritionally complete.
- Initial "Keto Flu" symptoms are common during the adaptation phase.
- Early weight loss often reflects water loss.
- There may be a risk of constipation if the KD is too low in fibre.
- Potential deficiencies in vitamins K, C, and B.
- Not recommended for certain metabolic conditions - liver failure, conditions affecting fat metabolism enzymes, porphyria, or chronic pancreatitis.
- If you are a type 2 diabetic taking insulin, it is essential to monitor insulin closely when reducing carbohydrates.
- Potential risks for Type 1 diabetics of hypoglycemia and ketoacidosis.
- Professional guidance is advised for specific health conditions.
The resurgence of the modified ketogenic diet
Even though the ketogenic diet has significantly evolved since its creation, with popular culture introducing variations that deviate from the traditional high-fat, low-carb approach. The "modified keto diet" (MKD) is the high-protein, low-carb version which has gained renewed attention in recent years.
The MKD is less restrictive than the cKD, following a ratio of 3:1 (3g of fat for every 1g of protein and carbohydrate), down to a 1:1 ratio. The MKD allows for less reliance on fat burning by allowing for more protein and carbohydrates and is therefore easier to adapt to and maintain over a longer period of time. It also incorporates more fibre-rich foods addressing concerns, such as constipation and nutrient deficiencies, from the classic keto diet.
Several factors may be driving the growing interest in this more flexible approach to keto:
- Weight loss appeal: quick and noticeable weight loss remains a primary motivator for many people adopting keto diets. The modified version offers similar benefits while being easier to follow.
- Flexibility: unlike the strict traditional keto diet, the modified version allows for slightly higher protein and carbohydrate intake, making it more sustainable for long-term use.
- Celebrity endorsements: public figures and influencers continue to popularise keto as a lifestyle, further boosting its appeal.
- Personalisation: advances in digital health tools and personalised nutrition strategies have made it easier for individuals to tailor ketogenic diets to their needs.
For those seeking a sustainable dietary approach with fewer restrictions, it may prove to be a good alternative - but consulting a healthcare professional who understands your goals is recommended before making dietary changes. Transition to a KD should be planned, gradual, and controlled.
This article is for informational purposes only, even if and regardless of whether it features the advice of physicians and medical practitioners. This article is not, nor is it intended to be, a substitute for professional medical advice, diagnosis, or treatment and should never be relied upon for specific medical advice. The views expressed in this article are the views of the expert and do not necessarily represent the views of Healf
