Conversations with Strangers: 3 Reasons Not to go on High Protein Low Carb Diets

For an updated review of the scientific literature on ketosis and ketogenic diets,

Please see:

Ketosis: Reviewing the Research and the Fad




I’m told that I have one of those faces. One of the ones you want to talk to. One of those faces that people immediately spill all their secrets to.  Random people on the street are constantly approaching me and wanting to converse about their music career, ex girlfriends, current boyfriends, dogs, and more often than not their health. My friend Oliver likes to say that it’s because people trust me immediately.  Although sometimes frustrating, mostly it’s just led to fun and interesting interactions with people from all walks of life.

Yesterday after a long day of participant visits and data analysis, I decided to take a walk through the presidio (a hilly wooded part of San Francisco). It was a gorgeous sunny day, one of those you imagine California has all the time. One of those days that rarely happen in foggy San Francisco. I climbed to the top of a hill and found a long bench with a view of the entire bay stretching out below me. I took off my jacket, kicked off my flats, and taking out my kindle, began to read, luxuriating in the feel of the warm sun and woody smells, and ignoring the tourists snapping photos around me.

I felt the bench creak and something hit my foot. I looked up to see a jewish man in about his fifties looking over at me. “Sorry,” He said, “You don’t mind if I snag the end of this bench do you? I don’t want to bother you. You look extremely comfortable reading.” I went back to my book, until I heard something buzzing in my purse under my head.

I picked it up. It was my friend, wanting to chat about his MCAT class, camping trip, and update me on his sexual exploits and feelings. I joked with him about my application process, about how I should have been an engineer (no one in healthcare feeds me for free), my struggles with the GRE, and about my bro trip to Seattle.


When I hung up, I noticed my bench friend had been eavesdropping. He turned to me, “Excuse me for listening in, but why are you applying for graduate school? You should be a comedian. You should be doing standup.” Well, that’s something new. I’ve never gotten that one. I mean I think I’m funny, but not comedian funny. He stopped me again, “Can I ask where you’re applying and what degree your trying to get. I told him I was trying to get a masters in nutrition, and he asked the question that always follows, “Can I ask you a personal nutrition question.” “Sure,” I responded.  This is the reason I chose this career path.

Here’s his background: he has high total cholesterol, low HDL, high bloodsugar, and high blood pressure. He’s taking Lipitor for cholesterol, and a beta blocker for blood pressure, and wants to get off of the meds. He told me he tried to lose weight for a couple of months through diet and exercise: focusing on eating a healthier diet, and exercising at least 45 minutes a day. He said it wasn’t effective and he lost 2-3 pounds at most.

He then told me that he’s now on a ketogenic diet, meaning he’s cut almost all carbs out of his diet, and suddenly the weight’s coming off quickly. He likes it and wanted to know my opinion, which I gave him, and which I will now share with you. So here goes:


Why Ketogenic Diets are Dangerous

  1. Ketosis is not fun, and not something you want to put your body in.IMG_1112

    You know how certain ketogenic diets (Atkins, Dukan, South Beach etc) say bad fruity breath is a sign of the diet working?  Well, that would be because you are forcing your body into ketosis. What is ketosis?  ketosis occurs when your body doesn’t have enough glucose to transport into cells to breakdown as energy.  Instead your body begins to break down fat.You may say yay to breaking down fat, but I say nay.  What you may not know is that an essential byproduct of the breaking down of fat are ketones.  Acetone is a ketone, and the cause of that nasty breath problem I mentioned before.  Ketones are slightly acidic and in high levels can potentially send your body into ketoacidosis dangerously altering the slightly basic pH of your blood (7.35-7.45).  This only happens in extreme cases as your body has buffers to prevent this (bicarbonate).  However, if there is a chance you are diabetic or prediabetic as this man’s elevated fasting blood glucose pointed to, then the risk is elevated.  Take it from someone who has experienced diabetic ketoacidosis, it’s extremely dangerous and miserable.

    Ketosis can also make you feel sluggish and lack luster.  Although per molecule, fat provides a lot more ATP than a glucose molecule, the brain functions best off of the breakdown of sugar to ATP to fuel cells.  As glucose is the preferred fuel source for the brain, not having enough of it can make you feel tired, light headed, and cloudy.

  2. IMG_1095Say goodbye to your kidneys.

    There’s a reason that a majority of your daily intake should come from carbohydrates.  The NIH recommends a break down of 60% of your daily intake from carbohydrates, 20-25% from fat, and about 15% from protein.  Increasing your protein intake substantially can be dangerous, because it puts added strain on your kidneys.  I would strongly suggest against it if you have proteinuria or any other symptoms of renal disease, as high protein diets can intensify these symptoms and accelerate renal disease progression.  Furthermore, diabetics should be extremely wary of following these diets as diabetic nephropathy is the leading cause of end-stage renal disease.  Finally, even for those who start high protein diets without any kidney problems, the risk of developing nephrolithiasis in otherwise healthy patients is increased.

    High protein diets also increase your risk of kidney stones.  Eating too much protein boosts your levels of uric acid, which can actually form a type of kidney stone (yes, there are multiple types of kidney stones).  High protein diets can also reduce your levels of citrate, a chemical in urine which helps prevent the formation of kidney stones.  I’ve never had one, but I’ve heard that kidney stones suck, and I’d rather not increase my risk of getting them.  Would you?

  3. Fat, Fat, Fat

    Most of you know that increasing your intake of animal based foods poses the risk of sending your cholesterol sky high.  What you may not know, however, is that excess protein in your diet is converted into and stored as fat.  This is counterintuitive, as most people go on high protein diets to lose weight, but contrary to popular opinion, all protein you eat doesn’t go straight into muscle building.  This means that unless you’re a gym rat lifting all day every day, all that excess protein is just being converted into and stored as fat.  Excess macronutrients (calories not burned) are converted and stored as fat.  This is why calorie restrictive diets have proven the most effective means of weight loss.

To conclude:  Choosing a low carbohydrate high protein diet poses many risks, and is not something I would suggest particularly to someone with the aforementioned risk factors.  If you are considering one, it is important to consult with a registered dietitian to create a plan that it safe and sustainable.

Carbs glorious Carbs, but choose the complex ones please!


2 thoughts on “Conversations with Strangers: 3 Reasons Not to go on High Protein Low Carb Diets

  1. Hi, I read this post after reading your post about the scientific findings on ketosis, but I think that you wrote this post first… After having researched what the scientific literature says about ketosis, do you still stand by everything in this post? Also, is it not true that excess carbohydrates (not just protein) are stored as fat, and in fact are more easily and quickly converted to excess fat than protein is? Ketosis may not be sustainable or ideal (after all, it is clearly a state of stress for the body), but if it were true that excess protein consumption leads to a high rate of fat storage, wouldn’t people in ketosis (including this man in your story) be gaining, rather than dropping weight in ketosis?

    – Fanny


    1. Hi Fanny,

      Thank you for your comment! This was written a couple years ago, and yes before I wrote the post on ketosis. I definitely do not stand by everything in this post (which is why I will be editing it).

      One thing I would like to clarify is that we really don’t have any research on the long term effects of ketosis, which is why I wouldn’t necessarily recommend a ketogenic diet as a sustainable lifestyle change. In fact, I probably wouldn’t recommend a ketogenic diet in most cases, with the exception of a patient who has epilepsy (there is a large body of evidence for ketogenic diets in patients with epilepsy).

      Also, excess protein consumption does not necessarily lead to a higher rate of fat storage (I’m sorry if that’s the impression you got from the piece), but in a rather round about way, some excess protein is eventually stored as fat.

      Furthermore, as I mentioned in the ketosis piece, although there is quite a bit of evidence to suggest that ketosis is effective in weight loss, there is new evidence to suggest that this method may not work for everyone, may not be sustainable, and may have a number of risks associated with it.

      Long story short: We know a lot, but there’s still much research that needs to be done.


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