Are You Lower-Carb Than You Think? - A Case Study | Chris Kresser

Are You Lower-Carb Than You Think?

by Chris Kresser

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how low is low carb
Fruits like blueberries, are a good option for a low carb diet. istock.com/BrianAJackson

Over the last couple of weeks we’ve been discussing the benefits and risks of low-carb and very low-carb diets. Laura, one of my staff nutritionists, kicked things off with an article called “Is a Low-Carb Diet Ruining Your Health?”, and I followed up with an article called “7 Things Everyone Should Know About Low-Carb Diets”. Then Kelsey, my other staff nutritionist, wrote an article called “The 3-Step Process for Determining Your Ideal Carbohydrate Intake”. In the near future, we’ll be featuring an article about the therapeutic uses for very low-carb and ketogenic diets.

Are you on an “accidental” very low-carb diet? Find out here:

The takeaway from all of these articles is relatively simple and uncontroversial—at least according to anthropological and clinical research:

  • Very low-carb (VLC) and ketogenic diets are useful therapeutic tools in certain conditions.
  • Some (but not all) people experience adverse effects from following VLC and ketogenic diets—especially when done over an extended period of time.
  • Very low-carb diets were extremely rare during the course of our evolution and are not the “default human diet” (as some have claimed).

Before we move on to cover the therapeutic uses of VLC/ketogenic diets, I want to address an issue that I see relatively frequently in my private practice. I’ve begun to think of it as the “accidental low-carb diet” phenomenon. The best way to explain this is to share a case study. 

The Accidental Low-Carb Diet: Frank’s Story

A few months ago I spoke to a patient—we’ll call him Frank. Frank is a 32-year old male who is on the SWAT team in a major metropolitan city. He came to see me complaining of extreme fatigue, insomnia, and exercise intolerance. These issues were obviously of paramount importance given his job.

About a year prior to our first visit Frank had started a low-carb Paleo diet. Some of his colleagues on the SWAT team were doing it with great results, so he figured he’d give it a try. He wanted to lean out and lose about 5 pounds of belly fat that he was having trouble getting rid of. After a few months on the low-carb Paleo diet, Frank did reach his target weight and body composition. 

But then the fatigue and insomnia started. A few months after that, he noticed he was having trouble keeping up with his training routine (which is, as you might imagine given his profession, quite rigorous). 

Frank reads my blog and listens to my podcast, and he had heard me say that some people can experience problems on a very low-carb diets. So he started to add some carbs back into his diet. This helped a little bit, but when he finally set up an appointment with me he was still struggling. 

When I talked to Frank, I asked him how he would characterize his diet. He said he used to do low-carb, but now he was on a moderate carb. I’ve learned over time not to accept this at face value, so I probed further. I asked him specifically how much carbohydrate he eats in the form of starchy plants and fruit (more on this below) on a daily basis. His answer: a sweet potato and about a half a cup of blueberries 3-4 times a week.

Although Frank thought he was on a moderate carbohydrate diet, when we did the math, it became clear he was on a very low-carb diet with fewer than 10% of calories from carbohydrate. Here’s how it breaks down:

  • Frank is 6’3 and 215 pounds (with a lot of muscle). He is extremely active. In order to simply maintain his weight, he would need to eat about 3,000 calories a day.
  • If we define a moderate carbohydrate diet as 25% of calories from carbohydrate, that means Frank would need to eat 750 calories a day as carbohydrate. At 4 calories per gram of carbohydrate, that comes out to about 188 grams of carb each day, or 1,316 per week.
  • A large sweet potato contains 37 grams of carbohydrate. 1/2 cup of blueberries contains about 10.5 grams of carbohydrate. In addition to these amounts of starch and fruit, Frank ate about 3-4 servings of nonstarchy vegetables each day (about 25 grams of carbohydrate on average). Given these numbers, Frank was eating about 365 grams of carbohydrate a week.

At 3,000 calories a day, this works out to about 7% of total calories from carbohydrate. That is most certainly not a moderate carbohydrate diet.

Do Carbs Cause Weight Gain? Frank’s Experience.

When I explained all of this to Frank at our appointment, he was pretty shocked. He was under the impression that eating a few sweet potatoes and some berries throughout the week put him in the “moderate carb” category. Obviously, this was not the case given his weight and activity level.

He was even more shocked when we calculated how much carbohydrate (again, from starchy plants and fruit) he’d have to eat to get to the “moderate” carbohydrate level of 25% of total calories. For Frank, to reach this target of 188 grams per day, he could eat the following:

  • Four servings of nonstarchy vegetables (25 grams)
  • One large Russet potato (64 grams)
  • One cup sliced cooked plantain (48 grams)
  • One medium banana (27 grams)
  • One cup of strawberries, halved (12 grams)
  • One half-cup of blueberries (11 grams)

This meant having a full serving of a starchy plant with two meals, and some fruit either with each meal or between meals—far more carbohydrate than Frank was eating previously.

Frank was initially reluctant to eat this much carbohydrate. He told me that he had noticed that carbs caused him to gain weight. But again, when we I dug a little deeper it became less clear that it was carbohydrate in general that caused weight gain, but a certain kind of carbohydrate (namely, processed and refined carbs). 

Turns out that Frank had very strong cravings for carbohydrate after a while on the VLC diet. Instead of increasing his intake of starchy plants and fruit, he’s stay extremely low-carb and then fall off the wagon by eating bread, pizza, or something like that. Not surprisingly, he would gain weight after these “indiscretions”. (Interestingly enough, he would also feel more energetic and sleep better afterwards.)

I asked Frank whether he gains weight when he eats carbs from whole-food, Paleo-friendly sources like starchy plants and fruit. He said he didn’t know, because he had never tried eating the quantities of these foods that I was recommending. So of course that became our next experiment. 

When I spoke to Frank about ten weeks later, he was ecstatic. His insomnia was completely resolved. His energy levels were not only restored, but higher than they’d been in recent memory. But what he was happiest about was his increased performance at work; Frank had recently placed highly in a national SWAT competition that his team competed in. 

What’s more, he accomplished all of this without gaining a single pound. On the contrary, he had lost a further 3 pounds of fat and was more “lean and ripped” than he had been on the VLC diet. 

If this had been an isolated experience with a single patient, I wouldn’t even bother writing this article. But in fact it’s a fairly common occurrence in my practice. I have every patient I see fill out a diet diary which shows me exactly what they eat on an average day. Then I ask them what their carbohydrate intake is like. I’d say about 50% of the time—if not more—my patients are consuming significantly less carbohydrate than they think they are

If you think you might fall into this category, you can use the guidelines below to calculate your optimal carbohydrate intake. 

How to Calculate Your Carbohydrate Intake

The first important thing to understand is that it’s far more useful to think in terms of of percentage of calories for carbohydrate than it is to think in terms of grams per day. I often hear people make recommendations for the number of grams of carbohydrate someone should eat. But this is meaningless when you don’t take weight and activity level into account. 75 grams a day may be a moderate-carb diet for a sedentary woman eating 1,600 calories a day, but it would be a very low-carb diet for a highly active male eating 3,000 calories a day. 

The table below illustrates the ranges for “very low carb”, “low carb”, “moderate carb”, and “high carb” using percentage of calories for carbohydrate. I’ve also included examples for how many grams of carbohydrate an average, moderately active male and female might consume per day given those ranges, as well as a list of health conditions/goals that might do well for each range.

Carbbohydrate Intake Chart

In order to calculate your exact target range, follow these steps:

  1. Figure out how many calories you should eat per day. This depends on your height, weight, activity level, and goal (weight loss, maintenance, or gain). You can use any number of online calculators to get this information.
  2. Once you have your daily calorie intake, multiply that number by your target percentage of carbohydrate. So, if your daily calorie target is 2,000 calories and your target carb intake is 20%, multiply 2,000 by 0.2.
  3. Once you have the number of calories per day from carbohydrate you need to eat (from step 2 above), divide that by 4 to obtain the number of grams of carbohydrate you should eat. In this example, you’d divide 400 calories by 4 to get 100 grams. That is the number of grams of carbs you need to eat each day.
  4. With this number in mind, you can then consult the charts below, or use online tools like NutritionData.com, to figure out which foods you can eat to meet your goals.

If you’ve never done this before, I’d encourage you to give it a try. If you’re like many of my patients, you might be surprised to learn that you’re eating a lot less carbohydrate than you thought.

Carbohydrate-Content-of-Selected-Starchy-Plants

Carbohydrate-Content-of-Selected-Fruits

Carbohydrate-Content-of-Selected-Nonstarchy-Vegetables

Now I’d like to hear from you. When you calculate your carbohydrate intake as I described above, are you lower-carb than you thought? What was the difference? Have you found that eating more “real food” carbs addresses your carb cravings without causing weight gain or other symptoms? Let us know in the comments section.

206 Comments

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  1. Really annoying that Chris never answered the total carbs vs. net carbs question. Kinda makes the tables/recommendations useless IMO.

    Considering that VLC/Ketogenic (Atkins induction phase etc) was originally supposed to be <±50g net carbs, Chris' tables are difficult to interpret.

    Why was the question not answered? Why wasn't the distinction mentioned in the tables in the first place? This is open to conjectures…

  2. Erm… so what if you have a neurological disease, digestive problems, adrenal fatigue, AND are trying to gain weight/muscle + workout 5-6 days/week. I think that puts me in all 4 recommended categories (very low, low, moderate, and high carb diets). Currently at about 40% carbs, which seems reasonable, but am now concerned that it isn’t ideal for my adrenals/neurological/digestive issues and would like to see sources. ((ie, are ‘low carb’ diets maybe just associated with lower instances of highly processed ‘bread’ products and/or relatively higher protein intake?))

  3. By the way Chris, thanks for the excellent articles I found on the Internet. I have suffered for years with gut dysbiosis, yeast infections and have gone of and on low carb diets. I recently lost about 25 lbs using MFP, but did not follow a moderate or low carb diet. Now I seem to be suffering from GERD symptoms – acid reflux, hoarse voice, excessive saliva (at night after dinner). I searched GERD on the Internet and found your articles. Glad I did before trying to decide if I should use PPI’s or not.

  4. Anyone out there know what a good percentage of carbs would be for a diet designed to reduce GERD (acid reflux)?

    • Just start by excluding all gluten grains (Wheat, rye, spelt, kamut..) . Not easy to do, ok. But very often, this is a magic bullet to cure GERD. Then only IF symptoms persist after 3 weeks going grain-free, you may search for other ways. Oh and try 2 tablespoons of natural, unfiltered apple cider vinegar in a big glass of water before going to bed. Works for many to diminish the symptoms of the nightly GERD.

  5. Hi Chris,

    Is it safe to eat cooked tapioca pearls everyday (as a source of carbs)? Since tapioca is derived from bitter cassava, it may have cyanogenic glucosides – correct? Is there a recommended limit to how much tapioca pearls can be safely consumed per day? And do tapioca pearls turn into glucose quicker than whole cooked cassava?

    Let me know,
    Kiran

  6. Great information! What would be the recommended carb intake for a preconception diet? Also, would you suggest spacing the carbs out throughout the day or having more at night vs. the morning?

  7. I’ve been following the paleo diet and also have started intermittent fasting. I don’t eat after 7pm and not before 11am. I’ve been in ketosis and have started back to karate following an injury. My class is at 10:30am and I’ve noticed I’m struggling keeping up. I’ve tried to add more carbs to help. I’ve read 1.5-2 hours prior to exercise eat a high carb / low to no fat food. Following the exercise, eat high carb/ fat/protein. I want to make sure I’m doing the right thing because I’ve dealt with severe adrenal fatigue in the past and I don’t want to stress my body out. I’m having a hard time getting/keeping enough carbs in my body to keep up in karate and I’ve noticed fatigue and headaches after karate. So far what I’ve tried is not working. I’m afraid to eat too many carbs because I’m trying to lose weight. Any advice/recommendations would be greatly appreciated!! Thanks!

    • On a ketogenic diet, it’s not adding carbs back, but sodium, potassium, magnesium, as low carb diets, tend to cause the body to remove these nutrients quicker than normal. Using Himalayan salt for sodium, apple cider vinegar. And a magnesium supplement, and you will notice the difference very quick. And plenty of water.

  8. Great article! I was definitely one of those. Do you recommend splitten the carbs out evenly throughout the day vs. having the bulk peri-workout?

  9. Hi Chris and Staff,

    Thanks for the article–very helpful. And, still, a question that about half a dozen of us have asked. Would it be possible to get a response? Are those ranges really total carb? shouldn’t they be net carb? Or if not, why not?

    Looking forward to getting this cleared up. Thanks!

    [For readers who don’t understand the question: Starch, sugars, and fiber, are all technically carbohydrates, and nutritional data charts include all three in the [unspecified] carbohydrate content of foods (total carb). But fiber, by definition, is indigestible, so does not contribute calories. Thus “% of calories coming from carbs” should refer only to the combined starch and sugars content (a concept called “net carbs”), not the (total) carb content listed in a nutritional data base.

    And yes, the term “low carb” is a misnomer, since many “low carb” diets are actually quite high in fiber. Really, most people mean “low starch/sugar” when they say “low carb.”]

  10. I might need to add a few more carbs. Whist I eat 50 gms of las night’s night’s spuds in the morning and maybe 150-200 in the evening, that only averages out at 50 gms of carbs/day. I only eat a few more starch veggies a dyad only a piece of fruit or two, that might not be quite enough; I am rather active, even at 63.

  11. Hi Chris! I’m convinced you wrote this post partly out of pity for the sad question about exercise intolerance I submitted to your podcast. 🙂 Well, all I can say is THANK YOU!!! This article described my symptoms almost perfectly, and I started eating starch as soon as I read it. Three weeks later, I feel like a new person! I’m completely floored by how much has improved — no more insomnia, tons of energy, and even the chronic cough I’ve been unable to shake for YEARS has almost disappeared. I’m just so happy to be able to move around again. Thank you, thank you, thank you!!!

  12. I think I’m late to this discussion party, but I too have had some adverse reactions to low-ish carbs. I was doing about 80 net a day but was lifting heavy 5-6 times a week, training to run a half marathon (so running probably 3 times a week), and “cutting” weight. I dropped from 214-189 relatively slowly on 2100-2300 cals a day (slightly more if I ran). I’m 6 foot, 190 (or was). Was dieting for 5 months probably

    Here’s the thing, my LDL-c jumped from 89 to 185 in – year. Sure my HDL and Trigs improved but they were always pretty good. TSH was tested at 4.3 and 3.5 (January and April)

    Since that high LDL test in January (and another in April where my LDL was175) I’ve added back in much more carbs (potatoes, sweet potatoes, sushi rice) and added in iodine at 225 mcgs a day try and lower my TSH and therefore correct my LDL.

    Anyone had similar experiences? Anyone successful drop their LDL simply by adding in more carbs? I didn’t mess up my thyroid for good, did I?

    • I should say I’m back up to about 210 lbs and feel much better. Energy has returned, “mojo” has returned, sleeping habits are better. I’m just scared to get my cholesterol tested again.

      • pls read the “Straight dope on cholesterol” series by Dr.Peter Attia to understand why LDL-C is an irrelevant number noone should worry about.

      • Pls read the “straight dope on cholesterol” series by Peter Attia to understand why nobody should worry about his LDL-C figures.

  13. I noticed that fast metabolizers need more carbohydrates than most in the chart you posted.
    I happened to read a post on fast metabolizers and insomnia that also discussed the nutrient deficiencies and health risks of a fast metabolism. (http://blog.nmrc.ca/insomnia-part-1-sleep-nutrients-falling-asleep/) Is this the same thing as being adrenalin dominant? I just got an update from the Brain Bio Centre in the UK, and they describe night-time hypoglycemia as part of that profile. They suggest a low-glycemic index diet.

    I would appreciate a post on fast metabolism at some point. What is behind it, how do you know you have it and what if anything do you need to do about it.

    I am one of those skinny people who can’t put on weight, prone to hypoglycemia if I don’t eat regularly and don’t sleep through the night (only 10 times in 20 years or something like that).

    • I too have been thin all my life. Very fit as a teenager into all sports, dance etc. Never been able to gain weight unless pregnant and would always lose anything gained not even trying. Two and a half years ago I dropped wheat to help with digestive issues and hopefully find some answers to a burning neualgia in my head. Over time and without me noticing as it was slow, I lost weight…not a good thing for me. I didn’t make the connection that I wasn’t eating enough carbs. I ate more fat, but that didn’t help. One of my pet peeves has been all these articles the paleo/primal communities have about losing weight but none about gaining weight. So this topic you have written about is perfect, but I wish I had known near three years ago. I wonder how many of us are quietly out here, suffering with poor sleep, struggling to keep weight on and wondering what’s wrong? My question has often been to myself, why is my metabolism so fast? I need some balance. Perhaps this article is a clue.

        • Thank you! I listened to the podcast and now I have made some significant changes in what and how much I eat. I hope to be seeing improvements…not expecting miracles, but slow and steady upwards would be nice. Thanks again!

      • “One of my pet peeves has been all these articles the paleo/primal communities have about losing weight but none about gaining weight.”

        ^^^Yes, yes, yes, yes, yes. Major annoyance of mine, and also one I feel is dangerous for many. While there certainly *are* articles about gaining weight, they’re in the majority and ‘lowering’ X is often seen/written about as an inherently good thing instead of, y’know, recognizing that *stabilizing* X is a good thing. (and that although X might frequently be too high, X being too low is also a dangerous/suboptimal thing)

  14. Hi Betty, yes I can, thank you for your interest. I have porridge made of water and 2 tablespoons of gluten free oats and 1 oz of raw nuts for breakfast, (and an egg when I’m training),lunch and dinner are piles of non starchy veg and salad plus 4 – 8 oz protein plus a portion of rice/buckwheat, millet or jacket potato or sweet potato or buckwheat pasta or rice and millet noodles. (As in 2oz when dry standard portion) I have a portion of fruit before each meal, 1 oz raw nuts in the afternoon and for snacks I have gluten free buckwheat, oat, chestnut and multigrain crackers with various nut butters. I have 2oz of 100% chocolate after dinner 🙂 So no added sugar or products with sugar in. I need to lose 8lbs to get back to my optimum weight so my grams worked out as 43g per day. This all adds up to about 3 times that! I am grateful for any help you can give me. Thank you, Susi

  15. So what should you do if you’re an athlete and would like to lose some body fat? I’m already pretty lean, but feel terrible when I cut my carbs down.

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