The ketogenic diet, otherwise called the ‘Keto-diet’ was really gaining in popularity. It is basically a high fat, low carb way of eating. This is a long video because this is a complex area that has a lot of myths about it where we don’t know everything yet and there are potential risks. But at the same time it can work really well for some people.
First let’s review what happens in the body. The basic premise is by having little energy from carbs its force body to use fat as energy, both from food and your own body fat. This fat from food or our own stores goes to our liver and gets turned into ketones, which is where the “ketogenic” comes from, as that means “generating ketones”. Our cells can use these ketones as energy quite effectively, including our brain.
When you have lots of ketones in your blood this is called ketosis, and you can measure the levels with a blood test. Some also use urine and saliva, but blood is generally considered the most accurate way to go.
There are a few important points to raise here:
- The levels of sugar in our blood remain generally within normal limits but lower = this is because sugar is created by the liver from parts of the fat and protein. So this dispels the idea that sugar is bad, as the body keeps a normal level of sugar in the blood. It is just too much sugar is bad, just like too much oxygen is bad.
- The levels of ketones in the blood should be <8mmol/l which is what is called physiological ketosis and that is achieved with these diets. This is very different from the dangerous form of ketosis called ketoacidosis seen in type 1 diabetes where the ranges are >20mmol/l with acid in the blood and dehydration.
So that’s the science of it. Let’s look at some of the evidence. Originally the ketogenic diet was one of the treatment options for epilepsy, and a well-respected journal called the Cochrane review showed that it produced a 30–40% reduction in seizures and in children the effects were ‘comparable to modern antiepileptic drugs’.
There is reasonable evidence for short term weight loss – as I mentioned before it is either as effective or just a bit more effective than other diets. It can suppress hunger and makes you feel full, and also because it is quite restrictive people generally eat less anyway. It can help you use up your fat reserves and may have positive effects on hormones like insulin in the short term. There is also some evidence suggesting it may help to improve blood sugars in people with diabetes. Part of the claimed benefits of the ketogenic diet is more rapid weight loss but this appears to be due to the loss of water weight initially. When you have a low carb diet you use up your bodies glucose stores called glycogen. Glycogen also stores water, so when glycogen stores are depleted, you flush out excess water. Hence you lose weight, but it wasn’t fat, it was water… So it is important to have this reality check so we don’t become a “keto-zealot”. Because as I discussed in a past video, after a year on most diets, they are roughly equal. Though obviously – some diets work better for certain people in certain situations.
So what about how we actually do it? If you are going ketogenic, the evidence suggests that you aim to eat <30-50g of carbohydrates a day which makes up 5% of your daily energy intake, that is about 2 pieces of bread a day or two small bananas/day, protein to ~1g/kg/day which is about 10-15% of your energy intake, and the rest of your energy from healthy sources of fat. Though there are multiple variations on the exact makeup of this. Ketosis usually kicks in after 3 or 4 days of eating less than 50 grams of carbohydrates per day. Of course, fasting (next video) can also put you into ketosis.
For specific food recommendations, as always I encourage you to do your research and work with a qualified health professional in this area before embarking on more intensive diets like this. General foods to stick to are:
- Eat lots of non-starchy vegetables like leafy greens, broccoli, capsicums, mushrooms and so on, plant-based sources of mono and polyunsaturated fats, like olive oil, avocado, nuts, seeds etc
- Fruits you can have include berries like blueberries, strawberries, blackberries, lemons, avocado and coconut but you generally limiting others
- Flours you can have include coconut, flax and almond flours
- Keep in moderation eggs, dairy and animal sources and when you do have animal sources have wild game, fish, free range chicken or regenerative grass fed livestock
- Remove or limit your intake of foods that are high in refined carbohydrate or salt, including processed foods such as sugary drinks, chips, cakes, biscuits, cereals, grains, pastries and lollies
- Keep trans-fats completely out.
I have put that list below this video. There are MANY ways to get into ketosis like a vegan ketosis of plant-based whole foods, and a more animal fat based ketosis. So, for example, you can be in ketosis by eating lots of fresh non-starchy vegetables like spinach, broccoli, capsicum etc and wild caught proteins like fish and wild land animals. eggs and healthy fats like avocado, olive oil, flaxseed oil and so on…. OR you could get into ketosis by eating bacon and butter which I do not think is a good idea… OR you can get into ketosis by fasting.
I think the evidence is far more in support of a plant-based whole foods ketosis if you are going to go low carb. To be clear plant-based does not mean plants-only. You can go vegetarian and vegan keto if you want and many people do (see Dr Will Cole’s Ketotarian link in the resources for more info and facebook groups “Vegan Keto”), but of course you can combine with whole food plants, healthy fats like avocado, olive oil, flaxseed oil, some eggs, fish, wild game and regenerative agriculture meat.
And how long do we do it for? This diet is certainly not for everyone, and the long term safety data is not there. It is generally recommended that if you decide to do it that you use it for short to medium lengths, around 6 months is the suggested duration for safety and then go back to a well-balanced diet with healthy carbohydrates for a bit. Then you can switch between the two if it suits you. The interesting thing about this is that even the advocates of this diet do not recommend being in constant ketosis, but rather eating in a way that takes you in and out of it. My experience is most people who are low-carb are not in ketosis, so don’t confuse them and don’t stress too much about it either. They eat mostly non-starchy vegetables (e.g. leafy greens, broccoli, peppers/capsicum etc), protein and fat based calories and minimise carbohydrates, but they are not being strict enough to be in ketosis.
The Dietetics Association of Australia and Diabetes Australia state that “in the short to medium term, low carbohydrate diets with optimal saturated: unsaturated fat ratios appear to be a safe and effective option for weight loss, improvement in sugar levels (glycaemic control) and heart health (cardiovascular) risk for adults with type 2 diabetes”. It also states that the long-term effect of placing this demand on the body has also not been tested and there is evidence to suggest that performance in mental and physical tasks could be negatively affected. Therefore, a diet that is very low in carbohydrate may not be physically or mentally sustainable as a diet pattern as carbohydrate foods supply many nutrients. These include B vitamins and fibre from grains, and vitamins, minerals, dietary fibre and other plant components such as antioxidants from fruit and starchy vegetables. So without careful planning, it can be more difficult to meet nutrition needs on a low carbohydrate diet.
As with all therapies, there are potential, key word here is potential, side effects that can include
- Vitamin and mineral deficiencies if you are not careful in getting good sources of them
- Initial flu-like symptoms called the “keto-flu”, which can last from a few days to a few weeks and includes fatigue, headaches and nausea
- Kidney stones
- Atrial fibrillation which is a heart disease
- Low blood sugars initially
- Some people get an increase in cholesterol
- Low-grade acid level in the body because of the fat and ketones
- Some women get painful periods
- Low carb eating may not be safe and is not recommended for children, pregnant or breastfeeding women, people at risk of malnutrition, people with kidney or liver failure, or those with a history of disordered eating or some rare metabolic conditions.
- There is some evidence that high animal protein diets can worsen heart disease
Ok, that is the ketogenic diet in a nutshell. Told you it would be long! Check out it and have a chat to your health professional if you want to try it.
Diabetes Australia position statement on low carb diets = https://static.diabetesaustralia.com.au/s/fileassets/diabetes-australia/8b4a8a54-f6b0-4ce6-bfc2-159686db7983.pdf