The Meal Matters Most

What Makes Healthy Food Healthy: From a Stress Perspective

Is it a problem not to eat fruits and vegetables on a ketogenic diet?


Organic market fruits and vegetables

Organic market fruits and vegetables (Photo credit: SalFalko)

I was thinking about this the other day. If our current accepted reasoning for why fruits and vegetables are important in our diet is for their antioxidant content (their ability to counter oxidant stress and free radical damage that can lead to diseases), then the problem with saying they are amiss when excluded in a ketogenic diet, a high fat, moderate protein and low carbohydrates (very few fruits and vegetables) diet, is that when the body goes into ketosis this oxidant balance is in part balanced by the diet amplifying our own level of internal antioxidants.   Did you know we could produce our own antioxidants? We have several pathways and enzymes such as glutathione which when under duress (ketosis is a form of nutrient starvation) it produces more defensive mechanisms, hence greater antioxidant production. So in ketosis, for some, these internal mechanisms are kicked in and dampens the reactive oxygen species that lead to disease. So it is conceivable for those that are on this type of diet may not need these outside sources of antioxidants from fruits and vegetables while on a high fat, moderate protein, low carbohydrate diet, since it abates oxidants in their own way.

Peter Attia of NuSi doesn’t feel he needs vegetables either, his ketogenic lifestyle diet consists of high fat, protein and just a few fruits and vegetables (see: “What i actually eat” by Peter).  Although Peter’s reason for his ketogenic lifestyle choice is that sugar is a toxin, when we remove a macronutrient, like sugar, this creates a nutrient “starvation”, much like starvation (or fasting) itself.  So in general when the ketogenic diet is typically instigated it isn’t about sugar being a toxin, but rather the benefits of fasting, the increased oxidative balances.  This stress management is typically thought to be where the benefit lies (this is still up for lively and interesting debate).  Altering these macronutrients, because its stressful, helps to balance stress. Stange I know. We’ll hopefull work this out in later post, but the toxic effect of sugar may be that some can not genetically or epigentically balance it, and therefore it creates excessive stress, which is toxic to the system.  So sugar, especially in the isolated forms of table sugar and HFCS, is toxic and “bad” for us. Whole food diets are better than processed and ketogenic diets may very well be good for subtypes within our population for several reasons other than getting rid of the “thing” that is sugar.  The more predominant reasoning may be rather how ketosis affects the system’s ability to handle stress.  And we are being subjected to greater and greater levels of stress. As a sidenote Peter isn’t convinced of my views on stress (he likes “toxic” as the word for sugar, where I might prefer stress that becomes toxic).

Peter Attia "What I Actually Eat" from

Peter Attia “What I Actually Eat” from

Ketosis presenting with this internal mechanism that allows for those same benefits of fruits and vegetables because of an increased internal production of antioxidants, may be one of the reasons why ketosis imparts a protective mechanisms as is suggested by researchers as the potential treatment of a myriad of neurological issues.

There of course could be many other reasons that we’d need these nutrients and foods in normal day life, like microbiota balances (from fiber), phytonutrients or polyphenols which have been under-appreciated. Also under-appreciated is that they may not work past the gut, but may have an important component action within the gut and interactions within the meals we eat (See “Do you really need antioxidants” and “Experts challenge Super Food Claims“).  For some, medically applying ketogenic diets AND antioxidants/polyphenols combined are referred to as the Mediterranean or Spanish Ketogenic diets.  There are researchers like Antonio Paoli  who are looking into the benefits of ketogenic diets and high level foods with polyphenols and antioxidants (I would suspect this is much like Peter with his EVOO, coconut and avocado? Good on ’em).

Do we need fruits and vegetable antioxidants which renders a ketogenic diet ‘bad’? No, not necessarily.  More research is clearly needed, but dismissing the ketogenic diet on the basis that it lacks fruits and veggies doesn’t really fly unless we can come up with different reasoning.


  • Epilepsy Res. 2012 Jul;100(3):295-303. doi: 10.1016/j.eplepsyres.2011.09.021. Epub 2011 Nov 9.Modulation of oxidative stress and mitochondrial function by the ketogenic diet.Milder J, Patel M.
  • The ketogenic diet increases mitochondrial glutathione levels. Jarrett SG, Milder JB, Liang LP, Patel M. J Neurochem. 2008 Aug;106(3):1044-51. doi: 10.1111/j.1471-4159.2008.05460.x. Epub 2008 May 5.
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  • [The two faces of reactive oxygen species].Zabłocka A, Janusz M.Postepy Hig Med Dosw (Online). 2008 Mar 26;62:118-24.
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Author: Lori Hogenkamp

Lori's passion is for food, the brain, science and stress shifting perspectives .

3 thoughts on “Is it a problem not to eat fruits and vegetables on a ketogenic diet?

  1. Pingback: Is sugar a toxin or a stressor? | The Meal Matters Most

  2. Pingback: Michael Pollan thinks the Paleo diet is wrong. Here is why he’s wrong. | The Meal Matters Most

  3. Pingback: Michael Pollan thinks the Paleo diet is wrong. Here is why I think he’s wrong. | The Meal Matters Most

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