At this point, most people have heard of the Ketogenic Diet. It's the diet you hear many influencers and celebrities claim as the driving force body transformations and health benefits. You or your friends may have even tried it for yourself.

But what exactly is the Keto Diet? And is it actually a healthy and effective option? A cousin of the the Atkins Diet, the Keto Diet will require you to limit you carbohydrate intake. By reducing your carbs to a certain point, you can push your body into ketosis, a state where your body burns fat for fuel instead of glucose and glycogen.

Some Keto Diets suggest your net carbs (total carbohydrates minus the amount of fibre from carbohydrates) be kept under 50g per day. Others suggest you need to keep to 20g or less. But how does this happen and does it actually work?

We spoke to Melrose Health expert Dr. Cliff Harvey - a PhD-qualified clinical nutritionist. He explains how ketosis works and the common myths you often hear about this diet.

Can you explain ketosis?

Ketosis is the metabolic state in which the body drastically increases its ‘ketone’ production to provide additional fuel, especially to the brain and nervous system, which typically rely on glucose (sugar) for fuel.

Do ketosis diets actually work?

While there is no ‘perfect’ diet for everyone, low-carb and ketogenic diets are useful for weight and fat-loss, metabolic syndrome and diabetes, and (especially over shorter timeframes) typically lead to better improvements in some key health risk markers like HDL cholesterol, triglycerides (fat in the blood), insulin, blood sugar, and inflammatory markers than comparable low-fat diets. They are also promising interventions for brain health and neurodegenerative disorders.

Are there any pitfalls or common misunderstandings?

There are many myths and misunderstandings in ketogenic diets. Many people still consider ‘nutritional ketosis’ to be the same as the pathological (disease) state of ‘ketoacidosis’ but they are very different. Ketoacidosis typically occurs in those with alcoholism or uncontrolled type 1 diabetes. Ketosis caused by a shift to a very-low-carb diet doesn’t cause the same elevation in ketones as ketoacidosis.

Another common misunderstanding is that everyone gets ‘keto-flu’ when they go on a ketogenic diet. While some minor flu-like symptoms can occur in the early stages of ketogenic diets, these are usually mild, resolve for most people within 3-5 days, and are not limited to ketogenic diets! In our published study, we observed that keto-flu was most associated with restriction of energy (i.e. under-eating) not with how much carbohydrate was restricted.

Finally, many people overeat fat and under-eat protein on a ketogenic diet, thinking that protein will ‘push them out of ketosis’ and that eating lots of fat will cause them to burn more fat. Both are untrue...if you overeat anything you’ll make it harder to lose fat and if you eat a little more protein, it won’t meaningfully affect the body’s ability to be in functional ketosis.

Do you have any tips or advice for anyone looking to make ketosis work for them?

Simplify, simplify, simplify. Stop worrying about small differences in grams of carbs per day and instead just focus on eating meat and veggies, and adding a little healthy fat (olive oil, hemp seed oil, flaxseed oil, MCT oil, coconut oil, ghee and butter etc.) Avoid obligate carbs (grains, sugar, fruit, legumes) and you should be all good! MCT or ‘medium chain triglyceride’ oils can also help you to get into and stay in ketosis more easily too. This gives you a little more ‘wiggle room’ for your carb and protein intake.

Are ketosis diets healthy or sustainable long term?

There’s no reason for us to believe that ketogenic diets are unhealthy over the long term, especially if they are based on unrefined foods and include plenty of veggies. However, they may not be necessary for long periods of time and most people start with keto and then, over time, add back in some of the unrefined carb choices as they achieve their goals. Very strict keto diets (with less than 5% calories from carbs) are also pretty difficult to stick to and so, more moderate approaches are probably best in the long term.