Is it possible that the keto diet doesn’t work for some people?


Is it possible that the keto diet doesn’t work for some? What to do if you experience loss of motivation and returning depression when trying to follow a keto diet? Should you be concerned about high levels of ketones? And how many calories and carbs should you eat?

Get the answers to these and other questions in this week’s Q&A with me:

Loss of motivation and depression has returned

My name is Andrea and I’m 56. My parents and I have been doing keto since end of August 2018. It was great to get the mental clarity, all lost weight. Mum is no longer diabetic. Don’t want to go back to carbs at all. BUT for several months I no longer have the mental clarity I so enjoyed and I also have depression again. Got off my medication fairly quickly initially. Don’t have a regular GP at moment since our remote surgery hasn’t got a permanent replacement yet and don’t feel comfortable talking to the two that are currently there.

I’m really struggling with this dilemma since I wake up easily enough but the deep depressive thoughts are there straight away, and I can’t get rid of them and I struggle to get motivated.

I am very hesitant to go back on medication because of the unpleasant side effects.

Any suggestions?


Hi Andrea. I am sorry to hear that your depression symptoms have returned. Depression can be a challenge to remedy long term for some. But the fact that it got better initially and then relapsed makes me wonder if you were in ketosis at first and are not any longer. You may want to check your ketone levels and use a nutrient tracker to make sure you are below 20 net carbs per day and getting adequate protein as well. Plus, remember that many non-food related factors impact our mood, such as sleep, stress management, social connections, exercise, time in nature and more.

Last, and perhaps most importantly, sometimes people benefit from anti-depression medications in addition to lifestyle changes. I usually encourage people to have a regular relationship with a primary care doctor who can help manage that. You could look for one on our find a doctor page.

Also, you may want to visit our detailed guide on mental health and low carb.
Best of luck!

Bret Scher

Levels of ketones

Hello doctor, and thanks for your help in advance.

I have been eating low-carb, zero sugar, moderate protein and moderate-high fat for like 1-2 months and a half now. Also fasting 16, 24 or 36 hours, it depends on what I feel like.

I have lost 8 kg (18 lbs) and reduced my body fat percentage. So I am now super heathy, normal BMI, normal subcutaneous fat, etc. (I was just a bit chubby, never obese, never diabetic).

The thing is… sometimes I measure my ketones and they are a bit high (7-8 max when fasting) and I get a little nervous and worried about the ketoacidosis.

I don’t know if it’s something that I should worry about or not, but as I am a bit of a hypochondriac… you know. I’d rather ask. Should I worry?



Hi Ortiz. That is a very high ketone level that sometime can be present with ketoacidosis. The key differentiator is that ketoacidosis also has a low blood pH. This can be tested with a blood test. In addition, people usually feel tired, nauseated, or have rapid breathing when in ketoacidosis.

That being said, I agree that those ketone levels are high. You may want to keep your fasts shorter or try a reduced-calorie “fasting mimicking diet” instead. Of course, if at any time you feel unwell with ketone levels that high, you should seek immediate medical attention.

Here is a post we have about ketosis vs ketoacidosis that may help.

Bret Scher

Is it possible that the keto diet doesn’t work for some poor guys (just like me)?

I’ve been eating a strict keto diet (no dairy, almost no nuts and intermittent fasting) for five weeks without losing weight, but experiencing almost all the side effects (the constipation more than several days even after taking the pills, terrible ketone rash, the acne which I never had before…), but after checking every possible reason and still have so many terrible side effects (the rash and the constipation with the bloated stomach truly drives me mad to some degree even though I do enjoy the food), I just wonder maybe it’s just not suitable for me (like I’m genetically unable to digest so much fat) that I have to quit…

Anyway, thanks a lot for all the information and the wide knowledge!

Hi Emeline. I am sorry to hear you are experiencing those side effects. For most people they will go away within a couple weeks, especially with adequate hydrate and electrolyte supplementation. For some, however, the symptoms may last longer. Although the keto diet is an effective tool for most people who try it, there are some who may not do as well. For those people, and you may be one of them, we usually recommend a low-carb rather than a keto diet. Low-carb can mean anything less than 100 grams per day, but you want to try 50 grams to start. Just make sure you stick to high-quality, minimally processed carbs. That will hopefully relieve the side effects you are experiencing while still giving you benefits of relative carb restriction and overall health gains.

Bret Scher

Carb amount and calorie amount

Concerned after six weeks of keto that two things may need tweaking:

  1. How many carbs per day should be my goal?
  2. Do the amount of calories matter as long as my macros are in tolerance?



Hi John. Good questions. In short, YES! Calories still matter even if you hit your macro targets. Remember, to lose weight, we want to burn our own fat stores for fuel. If we have a surplus of calories coming in, even if they are fat calories, we will burn those first before tapping into our fat stores. That is why we recommend dietary fat as a “lever” or a tool to adjust up or down as needed for satiety and weight loss.

As for your carb goal, that may differ depending on underlying carb tolerance and activity level, but staying below 20 g net carbs per day will usually ensure that you remain in ketosis, You can always experiment with increasing that number (as long as they remain high-quality, minimally processed carbs) to find your personal threshold. Just pay close attention to your metrics and go back down to 20 or less if you have any setbacks.

Bret Scher


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