My Thoughts on Low-Carbohydrate Ketogenic Diets
I was asked to write the article on a low-carbohydrate diet pattern for blood sugar and weight management in people with diabetes. The amount and type of carbohydrates to prescribe was at my own discretion, and I gave it very careful consideration after reviewing all of the available evidence. Although I’ve never personally cut carbs to the point necessary to induce ketosis, I was open to the possibility that there was evidence to warrant its use in diabetes and weight management. There has been a lot of research in this area within the past ten years, both short- and long-term studies, and I ended up citing 27 of them in the article.
Traditional ketogenic diets are extremely low in carbohydrates (usually 10-15 grams per day) and have been used since the 1920s for the treatment of childhood epilepsy with very impressive results. There is also emerging evidence regarding their use in therapy for certain types of cancer and neurological disorders such as ALS and Parkinson’s disease. Ketosis occurs when the body shifts from using glucose to ketone bodies and fatty acids as its primary fuel. The level at which this occurs varies somewhat among different people, but it’s generally less than 50 grams per day. The most famous low-carbohydrate ketogenic diet (LCKD) is the Atkins Diet created by cardiologist Dr. Robert Atkins in the early 1970s. It is mainly used for weight loss but occasionally for blood sugar control as well. The plan involves starting off at an “induction phase” of 20 grams of carbohydrates and adding back carbs until reaching a “maintenance” level which is also individualized. Dr. Richard Bernstein, who has lived with Type 1 diabetes for more than 60 years, recommends strictly limiting carbohydates with the goal of achieving normal blood sugar levels. By keeping carbs within 30-35 grams per day and 6-12 grams meal, smaller insulin dosages are needed, resulting in less error in matching carbohydrate intake to insulin and more predictable blood sugars. For people with Type 2 diabetes not taking insulin, very-low-carbohydrate intake prevents post-meal blood glucose spikes.
Is there any advantage to a VLCKD vs. a diet that is low in carbs but not low enough to promote ketosis? From the research I’ve seen, the answer is no with respect to the ketogenic aspect of the diet. The carbohydrate restriction itself is another matter, however. Do Dr. Bernstein and many other people with Type 1 and Type 2 diabetes experience better blood sugar control with carb intake at ketogenic levels? Definitely a very large portion do, but this is due to the diet’s effect on blood sugar regulation. For these individuals, the benefits of VLCKDs may very well warrant its use. But for weight management, I just don’t think that’s the case. Millions of people have lost weight on Atkins or other low-carbohydrate plans, but many have never achieved their personal weight goals, and most have regained at least a portion of the weight back.
Although it doesn’t work for everyone, I do believe a low-carbohydate diet can help people lose and maintain weight. Starting off at ketogenic levels may provide a psychological benefit due to early rapid weight loss that usually occurs, but there is certainly no indication to remain in perpetual ketosis for weight management purposes. While many low-carb proponents speak of a “metabolic advantage” that occurs with ketosis, characterized as turning your body into a fat-burning machine, I have found no convincing research to support this. It appears that the mechanism responsible for weight loss is a spontaneous reduction in calories due to reduced hunger and greater satiety on both low-carb diets and VLCKDs. And once a person reaches a certain weight, if the caloric intake is too high to promote further loss at this new weight, then weight loss will stall regardless of whether carb intake remains at ketogenic levels or not.
There may be another reason for slowed weight loss on a VLCKD. Recently, there have been several posts on various paleo/ancestral blogs regarding problems people have encountered on low-carb diets. I hadn’t really been following this issue that closely since I was doing a lot of lit review for the article. But it seems the main issues people have encountered are failing to sustain continued weight loss despite keeping carbs low, an inability to stay warm, and fatigue. These are symptoms of potential thyroid dysfunction (among other things). There is a good amount of research indicating that people may develop problems converting the thyroid hormone thyroxine (T4) to the active hormone triiodothyronine (T3) and instead convert a greater than normal portion to the inactive form, reverse T3 (RT3) at lower carbohydrate intakes, with the effect being more pronounced at ketogenic levels. In certain individuals this may result in lower resting metabolic rate. It’s important to note that this does not happen to everyone on VLCKDs, however, and thyroid function is very complex and affected by many factors in addition to carbohydrate and caloric intake.
I’m sure I’ll probably lose several followers after this post, but I have to be honest and state my true beliefs as a dietitian and fellow low-carber. I’ve never advocated a ketogenic approach for weight management, and I received some very unpleasant e-mails and comments on another member’s Facebook page when I recommended staying above 20 grams of carbs per day. (In that post, I neglected to mention the exceptions of treating epilepsy and possibly cancer and neurological disorders). As an outpatient dietitian in a large hospital, I counsel many people who are not even remotely interested in following a low carbohydrate diet, and that’s fine. People can certainly lose weight and even control blood sugar (albeit with larger doses of medication) on a higher carb, lower fat diet. I’ll be the first to admit that if I didn’t have blood glucose issues I’d be eating more carbs.
I truly feel that people should listen to their bodies and eat in a way that works best for them. From a personal standpoint, I tried introducing safe starches to my diet for several weeks after reading about the brilliant Paul Jaminet’s Perfect Health Diet and found that I could only tolerate just under 1/2 cup of potato or rice; any more and my blood sugar was well above 140 at the one-hour mark. To me such a small amount just isn’t worth the prep time! So these days the majority of my carbs are coming from all kinds of fruit as well as yogurt. My total carb intake for the day is about 90-100 grams (65-75 grams digestible or net carbs), and this works well for me. I’d like you to do what works best for you. If you feel great on a VLCKD and are able to achieve and maintain your goal weight by following this plan, that’s wonderful. But please be aware that ketosis isn’t necessary to achieve weight loss. As with any diet, it is calories in vs. calories out that determines the ultimate outcome on the scale.
If you’re wondering what my carbohydrate recommendations were for the article, as a general guideline I advised a starting point of about 85-110 grams of total carbohydrates (60-80 grams net carbs) per day using whole, unprocessed foods. (Interestingly, the Atkins website recommends 75+ net carbs daily, including grains, for lifetime maintenance). I know there will be many very-low-carb enthusiasts who think this is far too high, and I’m also expecting a backlash from other dietitians saying it’s way too low, unsafe, unsustainable, lacking in nutrients, and, of course, too high in fat and protein. But I feel good about these recommendations given the research I’ve reviewed along with my own experience and that of others. You know the lyrics from that old song: You can’t please everyone, so you better please yourself.
References:
1. Zhou W, et al. The calorically restricted ketogenic diet, an effective alternative therapy for malignant brain cancer.
Nutr Metab 2007; 4:5
2. Zhong Z, et al. A ketogenic diet as a potential novel therapeutic intervention in amyotrophic lateral sclerosis.
BMC Neurosci 2006: 7:29
3. Johnson CS, et al.: Ketogenic low-carboydrate diets have no metabolic advantage over non-ketogenic low-carbohydate diets. Am J Clin Nutr 2006; 83:1055-1061
4. Martin CK, et al. Change in food cravings, food preferences, and appetite during a low-carbohydrate and low-fat diet. Obesity 2011; 19:1963-19704.
5. Bisschop PH, et al. Isocaloric carbohydrate deprivation induces protein catabolism despite a low T3-syndrome in healthy men. Clin Enocrinol 2001; 54:75-80
Weight is a result, not a cause. Systemic inflammation is more important to consider for everyone and should be the primary focus if you are talking about a healthy diet. Are the extra carbs you are recommending promoting inflammation? If you are talking about grains, the answer is yes. If you are talking about starches, maybe not. So, eat the starch if you want to gain weight. Eat the grains if you want to age faster and develop heart disease, cancer, diabetes, Alzheimer’s, and dementia.
Hi Tory,
I’m not recommending “extra” carbs; I’m recommending enough carbs to prevent long-term ketosis. I don’t eat grains, but in terms of their consumption promoting inflammation, this doesn’t appear to happen in all cases. I know many people in their 80s who are extremely healthy and active and have eaten grains on a daily basis all their lives. We are all unique individuals with very different responses to food, environment, stress, etc. However, I do believe processed foods, chiefly trans fats and high fructose corn syrup, are dangerous to all.
No doubt, we agree on a lot and talking about finer points here.
I agree that we are all unique in our intolerance of grains. However, when you consider gliadin stimulates appetite and that’s why food companies like to put it in things, why put it in your body? I recommend William Davis’s “Wheat Belly” and or the book and/or podcasts by Robb Wolf. William Davis’s book might say a bunch of things that are hard to believe or except. Therefore, there is the need to dive deep into the Robb Wolf biochemistry side of things. Just my opinion, but wheat is not human food.
Obviously we are both on the anecdotal side of things but I will talk about the healthy people I know living into their 80’s as well… All five of them, ate pretty much whatever they wanted (including lard) and not one of them was fat. However, they all showed diminished mental function as the years went by. See systemic inflammation causes diabetes of the brain. Now all the other normal people developed heart disease, cancer, or diabetes and were everything but healthy if they made it to 80. I want to age like Dr. Art De Vany.
Anyway, I love your work, and like I said, we are just talking about finer points here. Thanks for what you do.
Tory Dutton: BRAVO
Franziska,
Good for you for basing your recommendations on evidence, not ideology.
“It’s a wise (woman)”, as Emerson once said, “that prefers results.”
Sam Knox
Thanks for clarifying, Tory. I’d like to age like Art Devaney as well 🙂
Thanks so much, Sam. Always appreciative of your feedback 🙂
One thing, though: I’m not sure we can conclude that ketogenic diets have no advantage over non-ketogenic low-carb diets for weight loss based on the results of the Johnson study. Both diets were restricted to ~1500 calories.
I’d be more interested in the effect on food intake in free-living humans.
Sam
I agree, although for many sedentary women 1500 calories per day is a reasonable amount. I’d like to see longer-term studies as well.
I am really glad that the ADA is recognizing low carb! I do about 60 grams a day that seems to work fine for me. I have talked to a few people that think just because they eat low carb, they can eat all the calories they wanted – then they didn’t understand why they were gaining instead of losing weight.
I’m very happy about it too! The ADA has arranged for articles to be written about several different diets for diabetes: Mediterranean, vegan, and now low carb!
Yes, it’s certainly possible to gain weight on a low-carb diet if you end up eating more calories. Eat too much bacon, cheese, butter, and cream — it can definitely happen!
Great post! I am a dietitian too and agree with most of what to say, especially that there is NO one-size-fits-all approach and that everything needs to be individualized. I personally aim for 20-40 g of net carbs a day because I have PCOS and am very prone to weight gain and because of digestive issues that prevent me from tolerating starches and sugars. Thanks for your work!
Thanks so much, Aglaee! PCOS and digestive issues can be very distressing and difficult to treat. I’m really glad that a VLCKD is working well for you, and I know the whole foods/Paleo aspect also plays a large role in improving your health. Best wishes for continued success 🙂
Looking forward to your article. Hmmm, I may have to tone down my criticism of the ADA a bit. Perhaps the alternatives have become too well-known to be dismissed.
Thank you for consistently presenting researched & balanced posts.
Thank you, Gerri! Yes, the ADA is definitely recognizing that there are many different approaches to diabetes management, which is very encouraging.
Hi, Franziska. Well done post!
Please let us know when and where your article is published by the ADA.
I lived on a 20-25 gram very-low-carb ketogenic diet for about four months. I generally felt fine and functioned well. But that’s just me, and I don’t have diabetes.
Anyone who scans the American Journal of Clinical Nutrition, as I’m sure you do, sees lots of articles on the apparent protection from some chronic degenerative diseases by adequate consumption of vegetables and fruits. Especially the colorful choices. People can debate for hours “what is adequate consumption.” It may be difficult to achieve that “adequate consumption” on a chronic very-low-carb ketogenic diet. My opinion is that it’s quite possible to hit that indefinite magical level if you eat 50-100 grams daily of digestible carb. I don’t see any necessity for the 250-300 g of carbs in the standard American diet.
My comments above are for a general nondiabetic population. People with diabetes have different risk/benefit calculations to make, including the unknown long term effects of many diabetes drugs. Even if 30 grams of carb a day are optimal for health and longevity, only an infinitesimally small number of people can do that. Compared to a 275-carb-gram/day diet, even a 100-gram-carb diet should substantially reduce a diabetic’s drug risk.
-Steve
Disclaimer: All matters regarding your health require supervision by a personal physician or other appropriate health professional familiar with your current health status.
Thanks so much, Steve! The article will be published online at
http://spectrum.diabetesjournals.org/ in late summer or early fall. However, only the archived editions are available to the public, so most people won’t be able to view it until late 2012 or early 2013. If you’re a professional ADA member you can probably access it as soon as it is published.
I’m in 100% agreement with all of your comments and express many similar ideas in the article. I’ve already planned a future post about the benefits of consuming lots of fruits and vegetables.
By the way, I still think your Diabetic Mediterranean Diet and Ketogenic Mediterranean Diet are two of the best, if not THE best, low-carb diets out there.
I wonder how many people are doing The Rosedale Diet. I wonder if he would consider that number infinitesimally small. If my understanding of it is correct its VLCKD.
Size is relative. What do you think of The Rosedale diet? Did I miss-characterize it?
Hi Jonathan,
I haven’t read his book yet, but my understanding is that while Rosedale does not recommend a specific amount of carbs in grams or as a percentage of intake, he believes carbs are unnecessary and should be minimized as much as possible. I’m interested to read his book to learn more about leptin’s influence on appetite and weight gain.
Much of what you write is conjecture and needs proper study. One issue you haven’t touched on is sodium. LCHFers tend to be sodium deficient and need supplimentation, yet this goes against popular health culture. Is it a wonder fatigue and cravings set in?
I agree the evidence does not exist yet to support the “fat burner” enzymatic profile many tout, yet evidence does exist to promote it from a hormonal position. There is no direct evidence against ketosis itself, if you discount bad breath. And constipation, which I don’t believe you write about, is a theoretical problem people who eat a true higher veggie paleo style diet rarely experience.
We need studies and science aimed at disproving LCHF almost as much as we need them disproving HCLF.
Hii John,
Thanks for your comments. Agree that more studies would be helpful, but I stand by my remarks. I said that ketosis is appropriate treatment for certain conditions and that restricting carbohydrates to ketogenic levels is beneficial for some people with diabetes. I didn’t discuss salt, constipation, or bad breath because side effects of VLCKDs was not the focus of this post. I am a proponent of LCHF in that I recommed carbs make up ~20% of intake and fat 50-60%. I just don’t believe that ketosis is necessary for weight management. The majority of research on VLCKDs has been conducted by researchers who favor them, and I’m sure they will continue to explore their short- and long-term effects.
What is necessary for weight management is a lowering of insulin levels. If that means hitting a ketogenic state, so be it. Ketosis itself only means fat is being oxydized. It doesn’t indicate what the source is, and it triggers no further benefits except for may better functioning brain and heart. Ketosis is merely a footprint in the sand.
Love the post, Franziska! I’m a big advocate of the ketogenic diet. Most people look at all of the foods you can’t eat on the diet because they contain carbohydrates and think it is incredibly restrictive and hard to follow, but I have found that what the ketogenic diet does to my appetite alone makes it the easiest-to-follow diet I’ve ever tried!
Thanks, Anthony! I’m glad you’ve found success on a ketogenic diet. Best of luck to you 🙂
I really appreciated both your thoughts and your citations. I’m preparing to do a short video on my new video blog regarding “miraculous” diets (I saw a magazine blaring, “Lose 10 Pounds Each Week – Better Than Liposuction”.) Your informtion, insights, and references are of great value, as well as interest. Thanks for helping point me in the right direction.
Bob Dunlop, RN, MSN – NurseBob
Thanks so much, Bob! Great website, BTW. I love the footage of Admiral Stockdale: “Who am I? Why am I here?” 😉
Franziska,
Glad you liked the site, which is certainly a work in progress, and my sense of humor. 🙂
I look forward to taking the time to read your other posts and broaden my “nutrition horizons”. I wish I had more time to talk with the RD in my office, but our TPN pharmacist seems to monopolize her time, and I and my colleagues are pretty focused on our own, non-TPN patient load…
Bob
I’ve bookmarked your blog and will definitely check back! Yes, inpatient dietitians spend most of their time on nutrition support, including TPN. I’m fortunate to be an outpatient dietitian who gets to spend the majority of the day providing nutrition ed to individuals and groups. Keep up the good work on your website and in your day job 🙂
Franziska,
Thanks for the encouragement. I hope I can keep your interest!
As to my work situation, I am working in an outpatient IV pharmacy. So, our patients are basically in the twilight zone between inpatient and outpatient. Sadly, the work is not really focused on education… More emphasis on assessment to determine readiness and safety for D/C. It’s a bit weird at times as an RN working for a PharmD management team – they tend to be very ignorant of both my scope of practice, as well as what I and my RN colleagues are actually capable of doing… So it goes.
Bob
Sorry to hear that. It can be tricky working under a different service. Glad you’ll be able to educate via your blog. Look forward to seeing future video posts!
I hope you will share the responses and comments you get as the article is published, especially since we won’t be able to access the article itself for sometime.
Oh, I definitely will! The editors asked me to decrease the word count and number of references, as well as making some minor changes. Overall, they seemed happy with it, so that’s good 🙂
I do much better on a predominantly ketogenic diet; a lifetime of migraines radically reduced as one benefit, and finally cured my insulin resistance. PhD nutritionist candidate Lucas Tafur lucastafur.com has some excellent posts on this subject.
It takes several days, up to a month, for some people to begin to really benefit from a ketogenic diet, so most people won’t unless all other options fail.
Hi Nan,
I’m happy to hear that you’ve had success with a ketogenic diet. I do think ketosis can be helpful for many conditions, including migraines. However, I don’t think it is necessary nor advisable for most people seeking sustainable weight loss.
Great post Franziska! Your right, it definitely varies form person to person and depends on how their own body reacts to various amounts of carbohydrates. However, i am a bodybuilder and i am a huge proponent of keto diets. It may be a little extreme and not appropriate for everyone. I personally only use it for short periods of time near the end of my cutting cycle. But, from my personal experience it has proven to be extremely effective at only targeting fat loss while allowing me to retain muscle mass.
Thanks so much, Darren! You probably also read my latest post (Part 2 of this article) in which I was much more enthusiastic about ketogenic diets. In fact, I’ve been eating 35-45 grams of carbs for the past 5 weeks or so and am very pleased with favorable effect this is having on my blood sugar. I’m so glad you’ve seen improvements in body composition with ketogenic eating. Nice blog, BTW — glad you like Chipotle too! I have their chicken or barbacoa salad with plenty of guac about once a week 🙂
I’ve been looking at your blog with interest, especially as I’m a low-carb diabetic myself.
I’ve actually been in nutritional ketosis about 20 months now, controlling my blood glucose well that way.
When I was diagnosed with diabetes, I had an HbA1c of 12.1%, so my diabetes was quite severe and uncontrolled. My doctor was ready to put me on insulin immediately, in fact. I was referred to a dietician who advised I eat … are you ready… a MINIMUM of 300g of carbohydrate daily. Wow.
I now eat 45-60g daily on about 3,200-3,500 daily caloric intake. So I’m extremely low-carb. (BTW I don’t overeat, in fact I’m currently dieting… I’m an active 6’3″, 225lb, 36″ waist mesomorph)
I do have one comment, you state: “as a general guideline I advised a starting point of about 85-110 grams of total carbohydrates (60-80 grams net carbs) per day using whole, unprocessed foods.”
… my comment is as a ‘general guideline’ that’s great. However for diabetics (many of whom are likely reading this post) it may be quite beneficial to start even lower, at a rate that will induce a ketogenic state. (For the average person this is usually under 30g a day.)
I recommend this not for the ketogenic state itself, but for the glycemic control that comes with it.
Once good glycemic control is achieved, I recommend people start adding a little more carbohydrate back into their diet – in the form of non-starchy vegetables and lower-GI fruit. This is where many diabetics make a mistake – by thinking they MUST remain ketogenic. (I do, others don’t necessarily have to.)
A diabetic person can quite easily find their optimum carbohydrate intake by “eating to their meter” and understanding healthy targets.
We know that at a blood glucose level of 140mg/dl (7.8mmol/L) damage starts happening in the body, and as-such both the American Association of Clinical Endocrinologists and the International Diabetes Federation recommend post-prandial levels always be kept below that level, which unless using large amounts of bolus insulin (which often results in weight-gain for diabetics), means eating low-carb.
For myself, I find I maintain good glycemic control at 60g a day or less total carbohydrate, unless I’m engaging in endurance exercise, when I’ll eat more (the intake increase reflects the amount/duration of exercise.)
… and thanks for not following the status quo… most dieticians offer horrible advice for diabetics.
Hi Glen,
Thanks so much for your comments and for sharing your own experiences and observations. You have probably already read my follow-up to this piece (My Thoughts on Low Carbohydrate Ketogenic Diets, Part 2), in which I agree with your assertion that some people need far fewer than 85-110 total grams of carbs per day and may in fact benefit from ketosis-inducing levels of carb intake. I’ve found that I personally need to stay below 15 grams of carbs per meal to achieve truly normal (<140) blood sugar levels. Eating to your meter is definitely the best strategy.
Wow, the RD recommended a minimum of 300 grams of carbs a day for you? That's ridiculous. Very glad you discovered low carb eating and are doing so well. Thanks again for sharing.
<140, is NOT NORMAL. Examine the works of Dr Bernstein who has worked to give us all a plan of having NORMAL Blood Sugars of <90.
The damage from high blood sugars can be managed if not avoided by managing what we eat.
I realize Dr. Bernstein advocates normal BG in the 80s, but this is often not possible for people with T1, even those who strictly follow his program. I did say <140, and my own BG has not been >120 (at least whenever I measure) since September of last year. I’m happy with that and do not believe damage occurs with BG <120 from reading many studies and also observing patients in real life.
Having been diag w T2 Diabetes about 18 months ago, I have joined the legions of Dr Bernstein’s followers and am on a VLCHF diet. Having first started on Metformin, I managed my diet according to DR B and others and have managed to maintain an A1C of 5.4 for the past 9 months with NO MEDICATIONS.
My blood works tells me that I have not been this healthy in years if not decades (I’m 67).
Keep up the good work. (My ideal diet, not considering calories, is 70% Fat, 25% Protein and 5% carbs (30 grams or less/day).) My weight has stabilized at 40 pounds less than when I stated and has been that way since giving up the medications in August last year.
thanks for your comments and congratulations on your success with VLC! So glad you found Dr. Bernstein and have been able to discontinue metformin and maintain great BG control. Losing 40 lbs is terrific too. Glad you’re enjoying the diet and it continues working so well for you.
I know this is an old thread but just wanted to share that after decades of feeling unwell, putting on weight steadily, feeling really drop-dead tired, I’ve found my personal sweet-spot (pardon the pun) is about 80 carbs a day. Not ketosis, but long-term sustainable, happy and energetic lowish carb. I found ketosis hard and nearly as fatique-inducing as sugar. Maybe I didn’t adjust well but after one month, I listened to my body rather thsn experts and now I feel amazing on low GI vegetables, and white meats, nuts, and occasional low GI fruit/berries. Too much fat makes me queasy though still, so it seems that high protein works for me. I’m losing weight steadily, and actually have the energy to exercise and the mental clarity to enjoy it.
Thanks for your comments and for sharing your experience, GG! I’m so glad you’ve found a carb level that works for you. I’m rarely in ketosis these days and eat very similarly to the way you do, and my total carb intake is around 70-80 grams as well, although digestible carbs below 50 grams. And like you, I feel great as well 🙂 Best of luck, and keep up the fantastic work!