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Are You Lower-Carb Than You Think?


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

We’ve talked before about the benefits and risks of low-carb and very low-carb diets. Laura, one of my staff nutritionists, wrote 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.”

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).

Now, 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. 

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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.




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Join the conversation

  1. Hey Chris-
    Great article. I find myself relating to the story. I’m a 23 year old graduate student. As a college baseball player I had trouble maintaining my weight as well as a clean diet as it is hard with travel. I started Paleo about 2 years ago and for the first time it was easy for me to stay lean. I was having a very hard time sleeping, however, like the problems you said before as well as a lack of sex drive. When I would binge on a pizza, similarly I would sleep great. I read The Perfect Health Diet and Your Personal Paleo Code and decided to eat sweet potatoes and white rice.

    When I tried the sweet potatoes I got a terrible pain below my navel. After trying yuca as well the same thing. The white rice not so bad but I still feel, the best way to describe it, is weird and not right after I eat all of these starchy carbs. The GI doc described it as IBS but it only happens with certain foods. I never had any problems with these before I started cleaning up my diet.
    I have no trouble with fruits like apples and berries however or nuts, which I now find myself eating a lot of. I want to include more carbs in my diet and I feel like the couple years of low carb as thrown my system off.

    I was wondering if you had any insight on what may be happening here? Any help is greatly appreciated.

    Thank you,

  2. Hi there Chris I love what you do and am an ardent fan of your podcasts and the whole paleo thing, your version of it at least.

    However I’m getting into a bit of a spin about this whole carb thing. I’d sort of taken on board that with paleo you didn’t need to restrict calories in order to lose weight just eat nutrient dense foods. I’ve just pumped in the relevant stuff into the calorie calculation stuff of your point 2 … I’m supposed to be restricting my calories to 1350 per day (I’m a 52yr old 5’5″ moderately active female) and eat 50g of carbs… more to the point that’s 200 calories of my precious 1350 in carbs! So, I’m really back to restricting calories again, right?

  3. Chris – This is a great article – and describes me exactly. I’ve been low carb for quite a long time now but I still have cravings that sometimes I just have to give into. When I do end up indulging – its the wrong stuff because that’s what happens to be available. Just this week I have been trying to force myself to at least eat more vegetables. I’ve been afraid of fruit for a long time now – but using the charts above I’m going to make myself a little food plan and see what happens.


  4. Thank you for these recent articles – they have really helped me gain perspective and I am already starting to feel better after adding more carbs back into my diet.

    I have stage 3 adrenal fatigue and struggle with getting to sleep but more carbs are making such a positive difference. I now see how potentially damaging the anti-carb crew can be, and even whole food carbs are demonised for causing diabetes and other health issues.

    Thanks again for your balanced, evidence based approach!

  5. I’ve been trying to stabilize Hubby’s blood sugar for months with lower and lower carbs (his diabetes is generation-old genetic). I’ve even tried increasing fat, fiber, lowering protein, putting 12 hours between meals, increasing chromium intake, all to no avail.

    Last night, we had taco wraps for dinner: 1/4 c. of shredded London broil, 1 T. Sabrosa salsa, about 1/4 c. grated pecorino cheese, and a good handful grab of shredded lettuce on Julian Bakery’s coconut wraps–he had 1. His numbers never went above 100, and stayed in a tight 94-98 range pre-meal, post-meal, and FBG the next morning.

    Could it be that he needs more veggie carbs than I realized? It could be. Tonight’s experiment is with 24-hour cold potato salad, and some sort of other salad that’s meatless (an N=1 to see if it works again). Meat + potato salad always equaled trouble in the past, since Hubby is a hyper-carnivore.

    If I end up having to feed him taco wraps the rest of his life just to achieve this kind of progress, I’ll do it–he’ll gladly eat them as long as I keep adequate salsa supplies handy.

  6. Fantastic article. I have been tracking my carbs for a little while now, and the tool I use tracks net carbs rather than total carbs, based on the argument that the fibre or sugar-alcohol content off-sets some of the carb content. So I would be interested to know if the tables and advice above is related to total carbs or net carbs? Many thanks

  7. Interesting article. Thanks Chris. I can’t help but wonder – is it possible that Frank’s issue was caused by a massive calorie deficit rather than a lack of carbs? And by getting him to increase carbs you increased his calories which solved the problem? I wonder what would have happened if you increased Frank’s calories by getting him to eat more fat instead….

    • As I said in my answer to a similar question above, increasing calories as fat does not have the same beneficial effect in most of these patients. I tried that early on.

  8. Great article
    I have two questions which diet or eating style would suit a person with very sore knees and joint issues ? I tried vegan it made no difference ? Maybe I wasent strict enough or did it for long enough ?
    And which is the best way to loose stomach fat about 6.5lbs to go , it’s a old beer stomach , have lost lots of weight just trying to shift the last lot

  9. I’ve spent the last nine months on an ultra-low carb diet (12 g carbs per day) because of a serious cancer, after being paleo for about 18 months. I’ve gotten the extreme fatigue, and it actually has a pretty easy solution. From various sources I’ve learned that VLC ketogenic diets deplete your body of sodium very easily, and that this leads to a feeling of extreme fatigue. I’ve learned to solve the problem by having about a half cup of bone broth (reasonably salty) every day. When I’m out of bone broth for a few days, I sometimes get serious fatigue symptoms. I drink a small glass of salt water (yuck) and I’m a new person in about an hour.

    I do think that VLC diets can probably cause long-term negative health outcomes. The only other symptom I notice is that my cortisol seems higher – I startle a bit more easily, for instance. On the other hand, I’m hoping that the diet will significantly slow tumor growth (the date is quite preliminary), which would be a reasonable trade. The silver lining is that I have lost a lot of weight with seemingly no effort (due to diet, not to medical treatments). I feel excellent, and after being moderately overweight my whole adult life am now at my slim high school weight at 44.

  10. Oh my goodness i thought i was eating very high carb and needed to cut back but i’m low to moderate. Better add some more starchy veges to my diet

  11. Chris, what are yours thoughts on lactose (milk arbs) counting? When I dial in just non-starchy vege, I am at very low carbs for the day. Mostly under 20g. When I add in two cups of coffee filled with milk my my daily lattes the count goes up to 35g carbs or higher. I have been including this and seeing no weightloss. Should I eat more veggies and not count milk carbs?

  12. Reading this makes me realize that I am too low carb
    most days. Thank you for the charts and the discussion

  13. If you have some dairy (primal) or nuts there are incidental carbs in many foods so dont just look at your starchie veg.

  14. I did a 30-day reset in July and was about to start adding things in when I got slammed with 3 days of vomiting followed by what is now 2 months of fatigue, insomnia and exercise intolerance, among other symptoms. Have tracked down C.diff. as an underlying pathogen, but I now believe that I’m on an unplanned VLC diet as well. Have begun an antibiotic and probiotic regimen, but will also start keeping track of my carbs. I mean, one can never have too many plantains, right?

  15. I just wanted to mention another issue that I’ve seen in myself and other post menopausal women – and that is a massive increase in LDL cholesterol on very low carb, moderate – to high saturated fat diets. My LDL freaked my doctor out as it went up to 7.5 – that is 285. I worked out I was only eating about 40 grams of carbs a day – not intentionally, just by default. I increased it to 120 or so, cut out the coconut oil, cream and butter, had slightly leaner meat, and switched out to monounsat fat sources like olive oil on salads. Within a few weeks it had dropped back down to 155. It is not just the low carb – it seems to be the combo of low carb and high saturated fat, combined with menopause. I also find my sleep is more solid, and satiety so much better with the higher carb meals.

    • The high LDL can often happen on LCHF but the lDL is usually the soft fluffy stuff not dangerous. It is the small dense oxidised LDL that is the dangerous one. You need to get your doctor to measure the LDL particles to see what your composition is. LCHF is a very healthy way to live. The higher fat is great for satiety and great for the brain. It is sugar and processed carbs that are atherogenic not fat

      • I did have them measured – I had mostly large fluffy – but a lot of it, slightly too much small dense and high oxidised LDL. Not a good picture. My Triglycerides are low and HDL very high too.
        Similar to a couple of other people that I know were tested. See Thomas Dayspring, high LDL is not necessarily safe even with low TG and high HDL

        • Thanks for that, Julianne. I’ve developed the same pattern as you (Pattern A, low trigs and high HDL, high LDL) and will check out what Thomas Dayspring has to say about it.

  16. Great! Thanks Chris – this explains my recent lack of energy.
    I was definitely under 10% carbs. Been having a mostly FODMAP diet for gut issues which meant only a handful of types of vegetables, almost no fruit and only sweet potato 2-3 times per week.

  17. I’ve seen exactly the same with my paleo clients. In females often crossfitters, they are doing fine until they do a paleo challenge at the gym, or they go on a low carb paleo diet to low body fat and increase the intensity and lengths of workouts. Their carbs go down to about 20 per day, with accidentally or by choice. They start getting menstrual issues, insomnia, cravings for carbohydrates, fatigue, reduced performance, slow recovery.They add more fat – because that is what everyone tells them to do. Their weight plateaus or increases. I have them eat at least 100 grams of starchy carbs a day, and a decent amount after workouts and problems reverse.