Ketosis, bulletproof coffees, keto flu, fat bombs… all buzzwords that you might hear related to the ketogenic (keto) diet. But what exactly is the keto diet, and why has it become so popular?
The keto diet is a very high fat, and very low carbohydrate diet (sometimes with as little as 20g carbohydrates per day). The idea is that almost all carbohydrates in the diet are replaced with fats, so that the body is starved of using glucose as its primary fuel source. After a few days, this forces the body to break down fat into ketones, which can be used as an alternative fuel source when glucose levels are low.
Very low carbohydrate means no fruit, starchy veggies (like potato, sweet potato or corn), bread, pasta, rice, oats, muesli, yogurt, legumes or fun foods, like chocolate or ice cream.
So what sorts of foods can you eat?
- Nuts and seeds
- Healthy oils, such as olive and avocado oil
- Butter and cream
- Full fat dairy products (cheese and small amounts of milk)
- Fatty fish, such as tuna, salmon and sardines
- Meats, and often fattier cuts of meat will be encouraged
- Low carb vegetables, such as leafy greens, zucchini, capsicum
Benefits of the keto diet
The keto diet was initially designed as a way of controlling seizures in patients with epilepsy. It then became a popular choice among dieters because of the perceived rapid changes in weight that can occur within 1-2 weeks of following the diet once the keto flu has passed (more on this later).
Because of the very strict rules surrounding the diet, it can initially be difficult adjusting your current lifestyle and eating habits to those that fit under the keto umbrella. However, with a myriad of recipe resources readily available on the internet, patients will often say that it is easy to adapt to and stick to over time.
Other reported benefits include mental clarity, reduced appetite, reduced cravings, improved blood sugar control and improved energy levels.
Sounds great! But let’s take a look at some of the downsides of the keto diet before we jump to conclusions…
Negatives associated with the keto diet
As I mentioned earlier, something that most people will experience is the keto flu. As one of my patients described, she literally felt like she had woken up one day and been hit by a bus. While your body is adjusting to using a new fuel source, you will feel tired, sore, lethargic, experience muscle cramping, bad breath, constipation and/or diarrhoea, and even flu-like symptoms. Unfortunately, this is a necessary part of getting your body into ketosis.
This also means that once you’re in ketosis, it is best for you and your body to stay in ketosis, otherwise you may experience the keto flu all over again (depending on how long you continue to eat extra carbohydrates). Your compliance to the diet should be pretty close to perfect, meaning that you must stick to the diet even when you are at a party, or going out to eat with friends.
The most significant drawback of the keto diet is the tendency for individuals to drastically increase their saturated fat intake. We know that this has a strong, positive correlation to increased blood cholesterol levels. In my experience, I have seen many patients try the keto diet, and report increased LDL, total cholesterol and triglyceride levels. In a keto diet, the increase in saturated fat can be attributed to higher intakes of fattier meats, butter, cream and cheese – you will notice that most keto recipes will use one or more of these ingredients to provide the majority of the fat calories.
Another disadvantage is that the limitation on the quantity of vegetables, and the exclusion of fruit, wholegrains and legumes on the keto diet drastically reduces your potential to include anti-inflammatory compounds into your diet. These foods are typically our primary sources of antioxidants and fermentable fibres that help to reduce inflammation and promote good gut health.
Based on the evidence above, I generally encourage my patients to achieve their weight loss goals using less drastic methods that will be more sustainable in the long term. My primary concern is the fact that the keto diet has the potential to increase your cholesterol levels, and I have seen this trend multiple times in my experience.
However, if you are still really keen on experimenting with a ketogenic diet, I would highly recommend doing your research, and even seeing a dietitian to help you optimise it for good health. When working with keto dieters, I focus heavily on improving the ratio of unsaturated fats (from olive oil, nuts, seeds, avocado and fatty fish) by replacing at least some of the saturated fat content (from fatty meats, butter, cream and coconut).
If you still have any questions about the ketogenic diet and whether it is right for you, please feel free to post a question or email me at firstname.lastname@example.org.