The keto diet: a dietitian weighs in

Shot to fame by its loyal following of prominent athletes and celebrities, the ketogenic diet (or keto for short) has become popular in the last few years. Many of its advocates swear it not only helps them stay in shape, but also promotes mental alertness and boosts energy. But when it comes to the keto diet, it’s important to know the health claims may not be all they seem.

At its core, keto is an extreme version of the carb-restrictive diets we’ve seen make headlines in the past, like the Atkins diet. The aim: to trick the body into burning fat for fuel instead of the glucose produced by carbohydrates.

The main difference though is that the keto diet is exceptionally low in carbohydrates. And when I say low, that means less than 20 grams of carbohydrates per day. That’s compared to the recommended 225 to 325 grams you’d consume as part of a balanced diet of around 2,000 calories a day.

It also puts emphasis on low protein and high fat consumption. So if you were giving the keto diet a go, you’d be eating a lot of very fat-rich foods: avocado, oils, nuts, seeds, creams, butters and so on. And it really depends on how closely you’re sticking to the low protein rules as to whether you’d also introduce meat, fish and other dairy products, too.

Ultimately, all of these regimented elements were designed for a very specific reason: to help control seizures in some people with epilepsy. For decades, the diet has been found to be quite successful on this front, but unfortunately that’s where keto’s benefits may start and end.

First up, in terms of weight loss, reducing your calorie intake by following the keto diet has no benefit over reducing your calorie intake on any form of modified diet. You still need to create a deficit and this isn’t necessarily made any easier by restricting entire food groups.

It’s also important to remember that weight loss and health aren’t the same thing. And when it comes to its effect on our overall health, there are two major issues I have with the keto diet:

1. It’s incredibly challenging to consume adequate fibre on the keto diet, because fibre is a carbohydrate. And there are countless health benefits of fibre – especially for the digestive system.
2. If you’re not mindful, upping your fat consumption can lead to an inadvertent increase in the amount of saturated fats in your diet. This could lead to increased cholesterol.

One of the main appeals of the keto diet seems to be the rapid, initial weight loss people have experienced. This might be considered a win for some, but it generally gives a false impression of what to expect, because it may not be sustainable.

Within our muscles we store glycogen (essentially a form of carbohydrates) with water. So when we go on a low-carbohydrate diet, our bodies use up our glycogen reserves and simultaneously deplete the water stored alongside them.

As a result, you tend to lose a couple of kilos in water weight within the first few days on the keto diet. But, as soon as you start consuming carbohydrates again, those stores replenish and the weight you’ve lost often goes straight back on.

In fact, the only instance where true weight loss occurs on the keto diet is if there’s an overall reduction in the calories being consumed. Some people do find that fats are more filling than carbohydrates, so switching to keto means they naturally consume fewer calories.

But by and large, even if weight loss is your sole goal (and here are a few reasons why it shouldn’t be), following the keto diet may actually be one of the most difficult paths to success. Not to mention one that’s likely to throw up an assault course of health issues along the way.

Marika Day is a nutritionist and Accredited Practising Dietitian who knows what the body needs to function at its best. With more than five years’ experience in the health and fitness industry, Marika's holistic approach to diet and exercise is tried and true. The information in this article is general information only and is not intended as medical, health, nutritional or other advice. You should obtain professional advice from a medical or health practitioner in relation to your own personal circumstances.