The ketogenic or ‘keto’ diet has been floating around the internet for a few years now, and it’s pretty well known for being the diet that restricts carbohydrates. The diet favours protein and fat and has been used by many as an experiment to lose weight, increase energy, improve health and even cure disease. But is the diet really all that safe and should you be giving it a go?
What is the ketogenic diet?
The keto diet is a very high fat, low carbohydrate diet. When I say low, I mean between 5-10% of energy from carbohydrates, or less than 50g. In comparison, the government recommend that over half of our energy comes from carbohydrates. Following the diet pattern excludes most fruits, starchy vegetables, grains and pulses. Instead, it is made up of meat, poultry, fish, eggs, cheese, cream, nuts and some low-carbohydrate vegetables.
Why is it used?
Originally developed to treat children with epilepsy, the aim of the diet is to reach a state of ketosis. The idea is that rather than using glucose from carbohydrates as energy, the body is forced to breakdown fat into molecules called ketone bodies or ketones (this is why it is called ketosis or ketogenesis) and use these for energy. As a result, mimicking the fasted state and aiding weight loss. This can be an effective short-term measure to control seizures for children with treatment-resistant epilepsy. The diet was designed to be used for up to 2 years and to be stopped early if seizure control was not achieved, all the while under the supervision of a registered dietitian. However, the diet has increased in popularity in recent years with the aim of promoting weight loss and improving health.
Are the health claims accurate?
There is evidence that short term use of a low carbohydrate may lead to weight loss, but there is no evidence to suggest a superior weight loss in the long term. The diet has also been associated with better short-term control of blood sugar in type 2 diabetes, but again, the long-term benefits are missing. There is also ongoing debate into the effects of the keto diet and cancer. Many of the early studies in this area use animal models and cells and show mixed results. Clinical studies have begun in some patients with cancer, but these are yet to conclude evidence and are ongoing. It is certainly not recommended at present for patients with cancer to start a ketogenic diet and they should always consult their oncologist when making any dietary changes.
The truth about the ketogenic diet
Yes, the diet will reduce daily calorie intake and cause weight loss. But this also shocks the body and much of the weight loss is water from the lack of carbohydrates. It works just like any other ‘diet’ would, reduce your energy intake. However there a number of reasons the diet should not be used for weight loss and is not recommended for the general population.
Did you know for every 1g of carbohydrate you consume and store for energy, your body holds 3-4g of water alongside this to help store the energy.
1.Weight loss is unsustainable in the long term
While in the short term you might see the number on the scales go down and perhaps feel some difference in yourself, this is unlikely to be maintained in the long rub. The diet is very restrictive making it very hard to stick to. Imagine those dinners with friends and family but without the pizza, pasta, potatoes, or bread!
2. The body needs carbohydrates
Carbohydrates are the bodies main source of energy, especially the brain. They provide the energy we need to walk, run, jog and everything in between! They are also super important for many processes in the body which we depend on to function.
3. Risk of nutrient deficiencies
Cutting out a whole food groups always comes with the risk of deficiencies as there is a reason the three macronutrients are advised as part of a balanced diet – we need each of them to function. One example of this is B-vitamins found in carbohydrates. Deficiency in this vitamin can lead to a lack of energy, low mood, dermatitis, cracked lips/mouth and increased susceptibility to infections.
4. High in saturated fat
High fat foods are encouraged as part of the keto diet and the distinction between saturated and unsaturated fat is not specified. Saturated fats increase our risk of high cholesterol, stroke and heart disease and should not be consumed in excess or as our primary fat source.
5. Low in fibre
Fibre is important for our gut health, digestion, and blood sugar control. Lacking this nutrient could lead to constipation, poor gut health and increase the risk of many vitamins and mineral deficiencies which are found in fibre. Fruits, vegetables, and grains, which the diet excludes, are all great sources of fibre. Our gut has been linked to our brain and many health factors including immunity and mental health.
6. Possible side effects
There are a range of side effects which may come with removing carbohydrates from the diet, these include:
- Low energy levels
- Brain fog
- Increased hunger
- Sleep problems
- Digestive discomfort
- Bad breath
- Poor exercise performance
7. May create unhealthy relationship with food
Restrictive diets add the risk of an unhealthy relationship with food because there is so much more to think about when it comes to your diet other than what you truly want. You forget about listening to your hunger and fullness cues, tuning in to what satisfies you and what you truly crave. Instead, you become caught up in what you ‘can’ have or ‘should’ have and before you not it your relationship with food is all confused.
Given the often-temporary improvements, unfavourable side effects and inadequate data demonstrating long-term safety, for most individuals, the risks of ketogenic diets may outweigh the benefits. Please seek professional support from your GP, a registered dietitian or nutritionist if you are following a ketogenic diet or would like more information.