3 Nutritionists on Why Keto Might Not Be Right for You

updated May 30, 2019
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(Image credit: Lauren Volo)
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We’re past January now, which means that we’re over the hump of Diet and Resolution Season — that annual stretch when everyone starts to feel pressured into Doing Something about their diet, their activity levels, or both. If you’re just hopping onto that bandwagon and are considering trying the keto lifestyle, read this first. We talked to three nutritionists who have some reservations to consider.

The ketogenic diet is both trendy and often misunderstood, which means that it might not be the right choice for some people — regardless of how many #ketolife pictures you’ve seen on Instagram. “The ketogenic diet is not a high-protein diet like a lot of people think,” registered dietitian Abby Langer told Kitchn. “It’s actually a high-fat, low-carb diet. You’re basically eating fat all day, which sounds delicious in a way, but can be quite difficult.”

I spoke to Langer and two other diet and nutrition pros who all explained why they have their own reservations about making keto one of your resolutions this year.

1. Rachael Hartley, Registered Dietitian and Nutrition Therapist

The keto diet has been used since the 1920s as a potential treatment for life-threatening childhood epilepsy, with mixed results. More recently, there’s been some preliminary research, usually on animals, looking at the ketogenic diet as a potential therapy for neurological conditions, like Alzheimer’s, and certain types of cancer, that have yielded interesting results. While in some cases an extreme medical condition might necessitate an extreme diet, I am concerned by the number of people going keto for general health or weight loss.

The keto diet removes food groups that provide valuable nutrients and energy, and just as important, are pleasurable to eat! In addition, there are many potential side effects, including loss of lean body mass (which slows metabolism), constipation, fatigue, high cholesterol, and disordered eating. Going on a restrictive diet is a sure way to damage your relationship with food, and putting a food off-limits — or in this case, entire food groups — fuels obsessive thinking about that food.

Restricting food frequently leads to overeating, so it wouldn’t surprise me to see someone who has done keto eventually binging on carbohydrates and sugar. I would highly caution anyone with a history of an eating disorder or disordered eating from going on the keto diet. For those looking to improve health or have weight concerns, instead of going on a restrictive diet — or any diet, for that matter — I work with clients on intuitive eating, a non-diet approach that centers on building a healthier relationship with food. People believe restriction is the key to healthy eating, but it almost always backfires.

2. Abby Langer, Registered Dietitian, “Canada’s Food and Nutrition Expert”

I don’t recommend keto to most people; it just hasn’t been studied widely or long enough for me to be comfortable doing that. I’d have to take a look at the client’s lifestyle and goals and see if they understood the commitment that the ketogenic diet requires. As a dietitian, I want anyone who is looking to make changes to their diet to make them for the long-term.

I think keto is really popular right now and everybody’s either on it or talking about it, which may make the diet seem easier than it really is. The truth is that most people will find keto too hard to maintain for the long term. You also can’t sneak a donut or some other treat like you would any other diet, because losing weight on keto depends on you being in ketosis; if you go over 50 grams or so of carbs a day (which, trust me, is very easy to do) you’ll break ketosis and the diet won’t work.

The keto diet is for people who eat to live, not people (like me) who live to eat. It’s for people who can eat a diet super-low in carbs and still function, still be active, and still live the way they want to live. People who love being social and going out a lot for meals will probably find this diet very challenging. It will also be difficult for plant-based eaters — it can be done, but it will be tough!

Nutrition does not have to be complicated; don’t make it that way.

3. Peter Haas, Nutrition Coach, Chief Growth Officer at The Good Kitchen

If you’re generally healthy, [keto] can be great in measured doses. I don’t think of it as a forever diet. I think of it as a tool for specific goals, circumstances, and types of people. Unfortunately, the ketogenic diet is super-overhyped at this point. There are people that are claiming that it’s a magical unicorn that grants wishes. [They claim] you can eat whatever you want, in whatever quantities you want, and lose body fat. They claim you’ll achieve a level of mental energy, clarity, and focus beyond the reach of mere carb-eaters.

Sorry to break the news, but there’s no such thing as magic — not even keto magic. Ketosis is an amazing survival mechanism that has evolved over millions of years. It is not a performance strategy, and I don’t think it should be a long-term eating plan either.

Keto has to be contextualized in the light of a person’s body composition goals, activity levels, current eating habits, and medical status. The biggest red flag [before starting keto] is a history of disordered eating, and not just anorexia or bulimia. Are you always on a diet? Is keto just one more extreme diet in a long list of extreme diets? Then I would advise adopting healthy eating habits and changing your mindset first. But to each their own. If you run a ketogenic diet, get the results you want, and feel great doing it, then by all means keep chugging along. I would still suggest allowing yourself some carbs on a regular basis to not be so restrictive and enjoy life.”


Is the ketogenic lifestyle right for you? Five people share why it works for them.

Keto for Newbies: Curious about the ketogenic diet? This high-fat, moderate-protein, and low-carb lifestyle puts your body in a metabolic state called ketosis, where you burns fat instead of carbohydrates as the primary fuel source. Read more here about what keto is and see all of Kitchn’s coverage on keto here.