Low carb vs. low fat in cool identical twin experiment

Twin Noakes

Low carb or low fat – which diet is more healthy? Here’s a cool identical twin experiment:

Twin Noakes

What do you think, which twin will win?


  1. Anna
    This sounds like a unique and cool experiment! However – I had a look at their site and neither of them appear to have any weight to lose. They are already quite thin women. The challenge would have been more interesting with overweight subjects.
    Reply: #3
  2. Barb
    They claim to be relatively thin...I would say that is an understatement. For this to be a real experiment, get a couple of twins that are really overweight, put them in a controlled environment rather than self-reporting, and do it for a period of time that would be long enough for bloodwork to stabilize. Then I'll pay attention.
  3. My interest in low-carb eating is not restricted to its effects on overweight people. I'm really primarily interested in finding out the long term health effects other than obesity. I'm especially interested in avoiding health problems like heart disease, cancer, etc.

    In the first episode of the Skinny on Obesity, Robert Lustig makes the following very interesting statement (about 10 minutes into the video) about the diseases that are in some way connected to the metabolic syndrome (type II diabetes, hypertension, lipid problems, heart disease, non-alcoholic fatty liver disease, PCOS, cancer, dementia):

    "Now here's the key: Everyone thinks those downstream diseases are because of the obesity and that could not be further from the truth. The obesity travels with those diseases, but the obesity is a marker for those diseases. 20% of obese people have a completely normal cellular metabolism and they will live to a normal age. 40% of thin people - normal weight people - have those same chronic metabolic diseases and will die of them. Nobody dies of the obesity per se - they die of the diseases that come from the metabolic dysfunction."

    With that in mind, I think it's certainly interesting to find out more about the effects of different diets on people of all weights. These twins are doing a good range of measurements, so they might find some interesting results even if there is not a big change in either twin's body weight.

    The biggest thing I would like to change about this study is the number of sets of twins.

  4. Suzie_B
    There are a lot of factors to consider. Do they have FH or are they ApoE4? It seems like their main concern is high cholesterol and low-carb often raises LDL by a few points. If that happens, will that freak them out since conventional wisdom says LDL is so bad, no matter the other improvements? Did they post their beginning lipid panels on their website? Also, asking the low-carb twin to eat snacks is overkill. Who needs snacks and three meals on low-carb?
  5. The REAL objective of their 'experiment' is publicity, PR & media coverage NOT scientific knowledge, since the 'experiment' is scheduled to last just TWO whole months, hardly time enough to prove anything, particularly in healthy young people at the peak of their metabolic health.

    To prove anything conclusively would require following these diets for a seriously protracted period of time of at least 10 years, if not 20 or 30 or even their entire lifetime as occurs in real life with real people. In terms of general health status & disease resistance, no changes of any physiological significance or of lifetime consequence can occur in just 2 months.

    Not to mention the fact that real experiments proving the superiority of low carb diets have already been done intermittently for the last 100 years or more. These 2 Barbie dolls & their dad are just getting their faces out into the public consciousness.

    Reply: #7
  6. Milos
    I agree on publicity, but in my opinion this could be good experiment. High cholesterol is very often in mom's family although they were all skiny and some family members died from stroke. Interestingly, most of them ate vegetables (all kinds) and pastries, but meat very rare. So for me, this experiment could be OK, although I agree that two snacks are not necessary for LCHF diet.

    On father's side, totally opposite. Most of the time they eat meat, very fat milk, fat cheese and what we here in Serbia call "kajmak" (milk cream with more than 60% of milk fat), but nobody ever had problems with cholesterol, diabetes, cardio vascular diseases, etc.

  7. Ok, I agree that this experiment bears some hallmarks of self-promotion. The slick design of the website, the career biography information, and the inclusion of previous media coverage all struck me as telling. However, for several reasons, I don't see that as reason enough to dismiss what they're doing out of hand:

    1.) Whatever the twins' motives, they are actually proposing to measure some relevant health metrics and if low-carb diets really are beneficial in the ways that most of us reading this blog seem to believe (or hope), it certainly shouldn't take decades for some of those benefits to manifest themselves in a measurable way. Detailed and expensive long-term studies on the possible benefits of low-carb diets are certainly a good idea, but what one gains by tracking subjects over many years is often gained at the cost of tight control (or knowledge of) exactly what the subjects are actually eating. The obvious limitations of short-term studies are offset to some extent by the potential for improved compliance. To my mind, both long- and short-term studies have a perfectly legitimate part to play in our deeper understanding of human diet.

    2.) Now I don't know a lot about Tim Noakes, but he seems to have done some impressive things over the years and he seems to enjoy some credibility in the public mind. Also, the fact that he was very open about his U-turn on dietary carbohydrates for athletes boosts his credibility in my eyes. His involvement in this experiment makes me more interested in its outcome.

    3.) I'm a reasonably scientific person and I find rigorous scientific evidence persuasive. I feel that I have some sense of what makes a well designed experiment and what doesn't. However, whether I like it or not, I have to admit that actual scientific rigour and credibility is not what matters to most people. Most people just want to hear a good story. In order to spread the good news about LCHF / Paleo / whatever to non-scientists (i.e. most people), the message needs to be crafted into a good story. It should be honest, of course, but it has to be palatable to a mainstream audience. A little bit of science goes a long way with most people - they really want a story that they (think they) understand and can believe in. For example, the 'story' of paleo works because people get it, even when they are actually quite mixed up about the scientific rationale of evolutionary health. If these twins can create a story that people get, then that doesn't make them any worse than most of the LCHF / paleo blogging heavyweights (or anyone that posts a comment here with a link to their own web site). A lot of people are just going to prefer reading about these twins than the scientific studies I enjoy reading about.

    4.) Almost nobody is motivated solely by the quest for expanding human knowledge, professional scientists included. Almost everybody is motivated to some extent by the desire for fame, acclaim, respect or career advancement. Even people that do useful experiments that indisputably contribute to human knowledge often do so - either consciously or unconsciously - for their own benefit. That's just human nature, and that motive doesn't automatically invalidate an experiment.

    Apologies for the long-winded comment!

  8. finn
    Sorry about not in topic but I think you should check this. Looney things going on in Finland again.
    en http://www.thl.fi/en_US/web/en/pressrelease?id=30737
    sv http://www.thl.fi/sv_SE/web/sv/meddelande?id=30737

    Also director of THL says it's wrong if you have lost weight by LCHF. Even if you feel good it doesn't mean you are healthy. People will die of heart attack.


  9. Cool project! Will be following it closely. :)
  10. Hi All,

    Jax here - you can call me Barbie Twin 1 :-)

    Thanks for all the chat - I'm finding it very interesting. We've had a whole bunch of different responses to our project and I don't begrudge anyone their opinion. Thanks to Ted Burke who really seems to have gotten what we're doing.

    This is a case of satisfying curiosity. I had a question, asked the relevant people to help answer it and this is where we are today. I didn't expect it to get this big and still find it hard to juggle with my life as a full-time mom, but I'm loving every minute of it.

    The point of the project is that it isn't scientific. It's not an experiment or a study, it's a public interest project. The beauty of it is that it's two everyday people who are relatively fit and healthy trying out something that thousands of people like us 'out there' and wanting to try out for themselves too. We can do both diets simultaneously because we're identical twins - and we're up for the challenge. Here in South Africa high carb vs low carb is a hot topic right now and so is Prof Tim Noakes. The best way to go about all of this was to create a blog.

    The fact that we're "barbies" wasn't our choice, it's our parent's fault - will forward all complaints to them :-) We did however choose to do the blog well - I just couldn't imagine doing a shoddy job on purpose. My brother's girlfriend is the top blogger in SA (Miss Moss) and I am so grateful to her for putting a nice-looking blog together. It's just doing something well, not trying to show off :-)

    Then when it comes to publicity - it's all relevant to the blog. My article on twins and the coverage the project is getting.

    Please feel free to read About The Project again for a more detailed response to your comments.

    At the end of the day this project may simply not be something that you're interested in - you may want dramatic results or pure science. But for out there who want to see what happens to
    'some like you' - then tag along and welcome to our world!

    Reply: #11
  11. A lot of studies - good, bad and indifferent - have been done on human diet. There is a mountain of literature. However, I don't see much real consensus on what a person like me should eat (apart perhaps from not too much refined sugar).

    Large studies that look at the bigger picture (e.g. following lots of subjects over many years) are never perfect and, while they can reveal interesting associations, rarely pin down cause-and-effect relationships. Conversely, (well designed) experiments that focus on one specific thing can reveal causal relationships with relative certainty, but that certainty unravels as one moves beyond the tightly controlled parameters of the experiment and into the rich pageant of real-world food choices.

    So I learn what I can from what I read, but I find few black and white answers. Instead, I let my own experience be the final arbiter of what I should or shouldn't eat. I experiment by eating different things and seeing how I feel (and occasionally tracking some measurable things out of curiosity). When I say "experiment", I really just mean "tinkering with my diet". I like to think that it's rational tinkering, but I hesitate to describe it as "scientific". That doesn't stop me from telling other people about it though! I bore people all the time by telling them what I'm eating and why. Sometimes, I tell other people what they should eat, although of course I should know better.

    With that in mind, I thought the criticism above was a little harsh because:

    1.) Science doesn't provide many black and white answers about what we should eat, so it's good for people to experiment themselves and reflect on what works and what doesn't. (Note: If one is lucky enough to have an identical twin, it makes sense to recruit them as a subject in one's personal diet experiments!)

    2.) Provided that people recount their diet experiments honestly, I think it's a great idea to share what they learn with other people. Obviously, others should keep in mind that it's anecdotal in nature and not to be taken as gospel.

    3.) If somebody is going to share their diet experiences, I think it's a great idea to do it on a blog. If it's worth hearing, why not share it with the world?

    4.) If you're going to blog, paying attention to the presentation really enhances the reader's experience. It's evident that a considerable effort went into making the Twin Noakes site look as well as it does.

    Jax, I wish you and your sister the best of luck in your experiment. Whichever of you turns out to be on the better diet, I suppose you'll both benefit in the long run!

  12. Hi Ted, Thanks so much for your insightful and kind reply. It's great to have you on board. Feel free to mail me interesting stuff you pick up on along the way that I can add to the blog and credit to you. Sounds like you're just as interesting to follow!

    Jax (jax@jaquelineduncan.co.za)

  13. Jackson
    What's funny about comparing the two diets is that low carb is simply easy and practical. Low fat is very difficult and easy to break from.

    You don't have to stress about portion control so much on low carb. Eat all the salmon and (accepted) veggies and salad you want at dinner time. It's much easier to cook this way and to dine out.

    I'm always on http://www.lowcarbkitchen.net for tips to help me get through the day with good food and new ideas.

  14. Interesting experiment but neither of them appear to have any weight to lose.

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