IF YOU have any interest in the world of diet and nutrition chances are you would have seen reference to a ‘keto’, or low carb, high fat (LCHF) approach to diets and weight loss.

Used clinically for many years, specifically in the area of epilepsy where it is used to help reduce seizures, ketogenic diets are also known for their relatively quick weight loss outcomes. Not a new area of nutrition but one that has become increasingly popular in recent years, the question is, ‘is a ketogenic diet the right diet for you?’

Ketogenic diets refer to diets that are particularly low in carbohydrates (ranging from 5-20%, or 20-50g of total carbohydrates and high in fats (up to 75% in total fat). This is as opposed to standard ‘diets’ which contain 30-50% carbohydrates and just 30% fat or less. Diets that are much lower in carbohydrate than the muscles and the brain typically need to function shift the body into a state known as ‘ketosis’ in which fat stores in the body are broken down into ketones which fuel the muscles and the brain in place of the carbohydrates when they are in limited supply. The result is enhanced fat burning and relatively quick weight loss as compared to a traditional dietary approaches.

There is no evidence to show that keto diets are damaging to the body. In fact, with their superior weight loss and associated reductions in inflammation in the body, there are a number of benefits, particularly for individuals with high blood glucose levels, fatty liver and significant amounts of weight to lose.

The primary issue with keto diets is that the total amount of carbohydrate consumed needs to be kept very low, or the body will quickly come out of ketosis. For example, a low carb diet for most of the day followed by an extra snack of chocolate or piece of banana bread will quickly negate any of the potential benefits of ketosis as the total amount of carbohydrate rises above the upper limits of 50g or so for the average adult.

Any diet — including a keto approach — will work if people stick to it. but in the case of keto diets, unless you are prepared to eat no grains, bread, cereals, fruit, starchy vegetables or sugars for long periods of time, it probably is not for you.

A keto diet uses foods that are high in fats to such as nuts, avocado, oils, oily fish and cheese to replace carbohydrate in the diet. For example, eggs and smoked salmon for breakfast, tuna salad with cheese for lunch and steak and avocado for dinner. While this dietary approach may appeal at first, the average person tends to get sick of eating such as limited variety of foods over time and will often crave more fresh fruit, grains and sugars over time which makes long term compliance, especially when individuals regularly eat in social environments challenging.

While the Atkins Diet promoted a low carb, high fat approach, the main difference with modern keto approaches is that the focus is on good fats such as olive oil, nuts, seeds and oily fish as opposed to fatty meats, full cream dairy and butter, for which a high intake is linked to increase blood fats. It also appears that the weight loss benefits and positive impact on inflammation in the body that is the result of a keto approach appears to negate any issues with consuming a high-fat diet in general, as long as the good fats dominate.

A less frequently mentioned issue with weight loss as a result of a LCHF diet is what happens when individuals return to their usual eating habits. While keto diets will work as long as they are followed, returning to a high carb diet is likely to result in rapid weight gain. What’s worse is if you try a LCHF diet again, you are unlikely to be able to replicate the results. This is because a reduction in metabolism has resulted due to muscle mass loss as part of the initial weight loss process. For this reason, when using a LCHF diet, expert advice to support a transition back to a regular style of eating is crucial to support long term weight loss maintenance.

Another big issue with a pure keto approach is that the diet tends to be relatively low in some types of fibre as grains, cereals and much fruit is eliminated. This can result in constipation, gut discomfort and means that the gut is not receiving the prebiotics known to benefit gut health and immune function long term. For this reason when planning a keto diet, much attention needs to be paid into the types of vegetables and supplements consumed to attempt to preserve gut health and function.

Keto diets and the fans that swear by them often refer to the improved physical and mental performance associated with consuming fewer carbohydrates. New research published by the Australian Institute of Sport to date has not supported this finding, with athletes on a LCHF diet failing to see the improvements in performance compared to a higher carb approach. While this is just one study, it does question the physical performance benefits often claimed by fans of LCHF diets.

So should you try it? Any diet will work when it is followed. The primary issue with a keto approach is that people do not do it properly to get the best results, or they are not compliant for the long periods of time it takes to get significant weight loss. If you do have significant amounts of weight to lose, or are struggling with high blood sugars or a fatty liver, it may be worth a try but do it with supervision from a dietitian to make sure you are doing it the right way to get the best results without damaging your metabolism or gut health long term.