Why you may choose the Ketogenic Diet
By Katharine Bennett, Dietitian / Exercise Physiologist ADP, AN, AEP
Low carbohydrate diets are not a new thing, particularly in the dieting world. The Atkins diet, South Beach diet and Durkan diet have all been around a long time!
The recent most popular low carb diet though is Keto, or the Ketogenic diet.
What is the ketogenic diet?
Traditionally the ketogenic diet was a high-fat, normal protein, very low carbohydrate diet, designed originally for clinical settings to help treat complicated forms of epilepsy. In a weight loss settings the diet has been relaxed slightly – instead of allowing only 20g of carbohydrates per day (approximately one slice of bread), it recommends up to 50g per day which is about the amount of carbohydrates in a slice of bread, a large apple and a glass of milk.
The diet works to burn additional fat as a fuel source by forcing the body into a state called Ketosis. Normally our brain, body cells use glucose as its primary energy source. In low carbohydrate diets such as Keto, where the body is depleted of glucose and glycogen stores, fatty acids are released from the cells and through metabolic processes in the liver, ketones bodies are formed. If this state of minimal carbohydrate intake continues ketone bodies can replace glucose as the main energy source.
Now like any diet there are advantages and disadvantages to going Keto.
Advantages and disadvantages of a ketogenic diet
Firstly, the body needs to get in to ketosis. When starting a ketogenic diet be wary you may feel fatigued and ‘foggy’ for the first couple weeks – it can take some time to adjust to the new energy source.
Secondly, experts are worried the higher fat intake may lead to heart and kidney health implication in the long term. Insufficient studies have been conducted assessing parameters such as blood pressure and cholesterol, but the good news is, short-term studies are yet to show statistical significance in these measures between those on a ketogenic diet or a regular fat, calorie-restricted diet after 6 months (1, 2).
The main reported side effect of Keto is constipation due to limited fibre intake (fruit, wholegrains and legumes are not allowed on the diet), but if one consumes adequate allowed vegetables and takes a fibre supplement this can be avoided.
What are the benefits of a ketogenic diet?
Many short-term studies have shown that the Ketogenic diet yields weight loss success. One factor being when we store glucose, we need to store water with it. When we deplete our body of its glucose stores, this water is no longer required or stored, hence assisting initial faster weight loss. To the diet’s credit, it has shown significantly higher weight loss than other calorie-restricted diets after 6 months. (1)
Other benefits include appetite reduction making it easier to not overeat, increased lipolysis or fat breakdown, there is also evidence of increased metabolism as it costs more energy to breakdown fat and protein compared to carbohydrates (2).
Research is showing benefits of the ketogenic diet for people with type 2 diabetes and helping improve insulin sensitivity, and for decades, there have been proven benefits with the ketogenic diet and epilepsy (2).
So there are many benefits to the diet, but also some drawbacks, so before starting please consider if this diet is for you. We recommend seeking advise from a professional to ensure nutritional adequacy is still met.
This diet is also not recommended and could lead to help complications for people with diabetes requiring insulin, people on blood pressure medication, and pregnant or breastfeeding females.
Brem et al, 2003. “A randomized trial comparing a very low carbohydrate diet and a calorie-restricted low fat diet on body weight and cardiovascular risk factors in healthy women”. The Journal of Clinical Endocrinology and Metabolism: 88 (4) 1617-1623
Paoli et al, 2013. “Beyond weight loss: a review of the therapeutic uses of very-low-carbohydrate (ketogenic) diets”. European Journal of Clinical Nutrition: 67; 789-796.