I feel like there’s one thing missing from a lot of the discussion about the keto diet (and similar extreme diets, really). Everyone talks a lot about whether or not it “works” with proponents on both sides, research supporting both sides, arguing that it does or doesn’t work for weight loss. The problem with this is the assumption that weight loss is the most important feature of a good diet. It’s not. You can lose weight eating lots of things that are not going to provide you with the nutrients you need. Weight loss is not the most important thing for health, despite what the media, the “wellness” industry, society, and even many health care professionals have lead us to believe.
Just because you feel good on a ketogenic diet and are losing weight doesn’t mean that it’s a good idea. As a dietitian, this is something that I really struggle with. It’s our job to support people. We can tell them that keto is a difficult diet to follow, that it may not be advisable, but when it comes down to it, they decide if it’s something they want to pursue or not. And if they do decide to pursue it, we can’t say “well, good luck, I wash my hands of you”. We have to help them undertake it in as healthy a way as possible. Which kind of blows my mind (and makes me glad that I don’t work in a counselling role) because if someone came to us with an eating disorder we wouldn’t support them in that. How can it be ethical for us to support people in following a diet that may cause them harm?
A little history of keto: the ketogenic diet originated as a treatment for epilepsy in children in the 1920s. It was intended to mimic the effects of fasting through the generation of ketones. In recent years this concept has caught on with people desiring to lose weight. After all, if ketones are produced during fasting, then if a specific diet can promote the production of ketones, it may also lead to weight loss. Not illogical. In some children with epilepsy who do not experience a reduction in seizures with medications, the ketogenic diet can be an effective treatment. However, there are potential side-effects.
A few long-term studies (1, 2) have looked at the effects of the ketogenic diet in children and have found such side-effects as: kidney stones, slowed growth, dyslipidemia, and fractures. There are also short-term risks (2, 3, 4) associated with the diet in children with epilepsy including: acidosis, hypoglycemia, gastrointestinal distress (including vomiting, constipation, diarrhoea, and abdominal pain) dehydration, hypoproteinemia, and lethargy. All of these studies have found low long-term adherence among children. There are many reasons for this: some children see improvement in symptoms, even after discontinuing the diet, others find it difficult to adhere to the diet, for some it’s not effective.
Of course, adults who wish to lose weight are not the same as children who have epilepsy. It’s hard to say if slowed growth in children would have a similar counterpart in an adult. However, many of the short-term side effects may be seen in adults, as may some of the other long-term side effects. In addition, there is potential for nutrient deficiencies when following such a restricted diet. Unfortunately, we don’t have research into the long-term effects of a ketogenic diet on adults using it for weight loss. We have some short-term studies that primarily look at it from the standpoint of whether or not it’s an effective weight loss diet. Maybe it’s perfectly safe, but maybe it’s not. Given that the vast majority of people who lose weight on the diet end up regaining it, and often more, is it really worth taking that risk? By following a keto diet you’re basically enrolling yourself in an uncontrolled experiment.
I think it would be interesting to know what the long-term effects of a ketogenic diet for weight loss are in adults. What I’d really like to know though is why we have become so obsessed with being thin that we are willing to adopt disordered eating habits at the expense of other aspects of our health and well-being. Why is it when we talk about a diet “working” we de facto mean weight loss? Why have we come to value weight loss over every other indicator of health? Why can’t we just value ourselves enough to properly nourish our bodies?