Nutritional Therapist Magdalena Marvell investigates the complex world of the Ketogenic diet and suggests more research is needed before we commit.
Exploring the Ketogenic diet
The ketogenic diet is a very low-carbohydrate, high-fat, and moderate-protein diet that aims to induce a metabolic state called ketosis.
Typically, the body uses glucose, derived primarily from carbohydrates, as its main source of energy.
By drastically reducing carbohydrate intake to between 20g and 50g per day – about the same as one or two slices of bread – the body doesn’t have enough glucose to use as fuel and starts to seek alternative energy sources.
In response, the liver converts fats into ketones, which can then be used by the body as an alternative fuel. When the body uses ketones instead of glucose, it is in a state called ketosis.
This is similar to what happens during prolonged fasting when the body converts stored fat into ketones to survive.
However, the ketogenic diet achieves this state by limiting carbohydrates while allowing the intake of other macronutrients, promoting ketone production without the need for fasting.
Nowadays, some believe that the body might prefer ketones over glucose and that being in ketosis could provide various health benefits.
The key benefit of a Ketogenic diet
The ketogenic diet may seem like a recent trend, but it actually has a long history, dating back over a century as a treatment for epilepsy.
Historically, fasting was recognised as an effective way to manage epilepsy, although it is not a sustainable long-term solution.
In the 1920s, researchers developed a therapeutic diet that mimicked the effects of fasting without the need for prolonged food deprivation, specifically to help children with epilepsy.
This diet was the ketogenic diet, and it proved effective. It continues to be used today, particularly for children with epilepsy who do not respond to other treatments.
Since the 1990s, there has been growing interest in the potential benefits of the ketogenic diet for various health conditions.
The ketogenic diet has been extensively studied for weight loss, with evidence indicating it can be highly effective.
It also appears to benefit those with metabolic conditions like insulin resistance or type 2 diabetes. In these conditions, the body struggles to process glucose efficiently with insulin, but reducing carbohydrate intake leads to less glucose and, consequently, a decreased need for insulin.
Research suggests that individuals with metabolic issues may develop better insulin sensitivity on a ketogenic diet, improving their ability to handle glucose while primarily using ketones for energy.
The ketogenic diet has also shown promise for individuals with polycystic ovary syndrome (PCOS), a hormonal disorder affecting the female reproductive system, often associated with excess weight and insulin resistance.
By enhancing weight loss and insulin sensitivity, ketosis can help alleviate other PCOS symptoms1.
Beyond weight and metabolism, emerging evidence suggests that a ketogenic diet may benefit brain health. Some scientists hypothesise that ketones might inherently support brain function2.
While research is still in its early stages, there are indications that a ketogenic diet could improve mental health conditions like depression and anxiety, as well as brain disorders such as Alzheimer’s disease.
Additionally, adopting a ketogenic diet typically involves eliminating ultra-processed foods, leading to various health benefits, including reduced inflammation and improved gut health.
Are There Misconceptions Surrounding the Ketogenic Diet?
There appears to be a wide range of potential benefits to a ketogenic diet, but many misconceptions still persist.
A key point is that there isn’t just one ketogenic diet. As long as fat is used for energy instead of carbohydrates, it qualifies as ketogenic. However, there are four different recognised medical ketogenic diets.
For example, the classical ketogenic diet derives 60-80% of its calories from fat, with less than 10% from carbohydrates. In contrast, the modified ketogenic diet gets only 50-55% of its calories from fat, and up to 20% from carbohydrates, with a slightly higher protein content.
The amount and type of fat depend on the specific ketogenic diet being followed. A common misunderstanding among the public and some health professionals is that all ketogenic diets need to be high in fat. For many using the ketogenic diet for weight loss or type 2 diabetes, a high-fat intake is not desirable.
Nevertheless, most ketogenic diets are much higher in fat compared to standard Western diets because a keto diet lacking fat would result in a significant calorie deficit, and sufficient energy intake is necessary for survival.
Another source of confusion is the distinction between a low-carb diet and a keto diet. While all keto diets are very low in carbohydrates, most low-carb diets are not ketogenic.
Ketosis – energy for brain health
There is a growing belief that ketones are beneficial for brain health, supported by emerging research.
Some studies suggest that ketosis may provide steady energy levels, which could help alleviate issues like brain fog and low energy. The reliance on fat for energy, rather than carbohydrates, avoids the highs and lows associated with sugar and carbohydrate consumption, providing a more consistent energy supply throughout the day.
However, there are differing opinions on the effects of ketogenic diets on the brain. Some experts note that during the initial transition from glucose to ketones – often referred to as ‘keto flu’ – individuals may experience symptoms such as brain fog, fatigue, irritability, and preoccupation with food. These symptoms typically occur as the body adjusts to its new energy source.
Staying in ketosis for several weeks is recommended to fully realise the benefits and activate fat-burning pathways. Proper planning and adjustment of fat and carbohydrate intake are crucial for success, though this process can be time-consuming.
Ketogenic diet for women
The effectiveness and suitability of a ketogenic diet can vary based on sex and life stage. Carbohydrates play a crucial role for menstruating women, as insufficient intake can lead to hormonal imbalances. The body’s need for carbohydrates fluctuates throughout the menstrual cycle.
During the luteal phase, which is the second half of the menstrual cycle, the body relies more on carbohydrates to produce the hormone progesterone. While some evidence supports this, more research is needed to fully understand the relationship.
This concern primarily applies to menstruating women. Once women reach menopause, their need for carbohydrates decreases as their bodies become less tolerant to glucose. In these cases, a long-term low-carb approach, ranging from 50g to 100g of carbohydrates per day, may be more appropriate.
The need for further research on the Ketogenic diet
While a low-carb diet appears to be more manageable than a strict ketogenic diet, some research has been compromised by participants’ difficulty in maintaining ketosis.
Many studies suggest the need for more comparisons between ketogenic diets and other dietary approaches, such as the Mediterranean diet.
Despite its popularity, the ketogenic diet lacks sufficient long-term research to definitively determine its safety. Some studies indicate potential long-term negative effects, such as premature organ aging3 and increased LDL cholesterol4 which could raise the risk of heart disease and strokes.
Should we follow a Ketogenic diet?
Nutritional needs are highly individual. Evidence suggests that a ketogenic diet may be beneficial for specific conditions, including drug-resistant epilepsy, weight loss, metabolic disorders, and potentially some mental and brain disorders.
However, caution is advised due to the incomplete understanding of the long-term effects of sustained ketosis. Additionally, the type of ketogenic diet can vary significantly, such as a vegan modified ketogenic diet versus a carnivorous ketogenic diet.
Before making any significant dietary changes, consulting a doctor or registered nutritional therapist is recommended.
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