While the keto diet has been studied in different contexts, this article primarily focuses on keto and weight loss.
Low-carb diets are nothing new, but keto differs as it is more extreme. The diet requires you to drastically limit your carbohydrate intake (e.g. bread, rice, starchy vegetables, fruit) and replace it with fat. Overall it is a high-fat, moderate protein, very low carbohydrate diet. If followed religiously, it puts your body into ketosis which is when your body switches from burning carbohydrates to burning fat for energy.
It is an established strategy used by doctors to manage infants and children with epilepsy. However, in the past few years, it has exploded in popularity among people who are trying to shed some weight.
To lose weight on a keto diet (or any diet), you still need to be in a calorie deficit (you need to eat less calories than you are burning). Ketosis can suppress your appetite, making it easier to stick to a calorie deficit and achieve weight loss. But note that eating even slightly too much carbohydrate or protein will kick you out of ketosis.
For most people, the drastic restriction of carbohydrates is not sustainable over time. In the long haul, there is little difference in weight loss between a ketogenic diet versus a regular carbohydrate diet.
A low carbohydrate (potentially keto) diet might be beneficial for the management of blood sugar in type 2 diabetes. However, the evidence in this area is limited and might be medically risky for those on certain medications such as sulfonylureas or insulin. It should only be done under professional guidance.
The keto diet pros and cons:
Carbohydrates have been eliminated in many diets and keto is no exception. While we know some carbohydrates should be limited, e.g. sugars, refined flours, with keto you will have to eliminate even the healthy sources of carbohydrates including whole grains, legumes, most fruit, and starchy vegetables. Unless your keto diet is well-planned you can be short on essential vitamins and minerals.
Furthermore, these healthy carbohydrates provides us wide variety of types of fibre, which promotes a diverse and thriving gut microbiome and is associated with good overall health. If you are following the keto diet, focus on getting enough fibre (at least 25-30g/day) by eating plenty of vegetables, as well as some nuts and seeds.
Note that you can continue to eat carbohydrates and still lose weight by choosing portion sizes and carb sources wisely. Focus on choosing high-fibre carbohydrates such as legumes and whole grains as they keep you fuller for longer and are shown to benefit your gut microbiome.
If your keto diet emphasizes animal-based foods such as meat and butter, you run the risk of eating far too much saturated fat. This can raise your ‘bad’ LDL-cholesterol levels and increase your risk of heart disease. Whether you follow the keto diet or not, you should focus on choosing heart-healthy unsaturated fats like avocado, olive oil, nuts, and seeds and limit saturated fats like fat from meat, butter, palm oil and coconut oil.
Currently, there is limited long-term data on the keto diet. The keto diet has helped many lose weight in the short term and may help with controlling your appetite and blood sugar management, however, it is very restrictive which can make it harder to stick to in the long term. The keto diet is not suitable for everyone. If you are considering keto, consult a dietitian or doctor trained in this area.
Last modified: August 1, 2022