Home Weight loss Study: More weight lost on higher carb diets for some

Study: More weight lost on higher carb diets for some


I saw this quote in a Psychology today article recently “If all you have is a hammer, everything looks like a nail.” (The right tool for the job). It’s not new of course, it’s one we’ve heard often. But as I reflect over my varied careers and life experiences, I  realise how often I’ve fallen into the “hammer trap”, where a particular experience colours my world view profoundly.

It goes like this: Something I’ve tried – whether it be a diet (Zone, Paleo, low carb, raw vegan …, name yours) or some self improvement course, religion, inspirational book, peak experience, adventure, therapy, medication, sport, exercise.. you get the picture. This thing you experience – it changes your life in some way, in fact it makes it profound difference. Every issue / health problem you see others having – your recent discovery appears to you be the answer.

As a group of paleo nutrition, and often low carb advocates – we tend to view the world’s health / weight problems as though paleo / low carb is the answer to everything. E.g. low carb will fix everyone who is overweight, it’s even good for athletes once they get used to burning fat instead of carbs…

I’m not saying it isn’t, I’ve seen incredible results in many people, however – I’m also aware of how science changes and evolves. And how little we really know, and how varied humans are. [Edit: To date I haven’t seen any evidence against a ‘paleo’ paradigm being the best dietary advice – by this I mean removing grains, especially gluten grains, chemically extracted vegetable oil and other nasty fats like trans fats, processed food, multiple synthetic additives and sugars – especially fructose. This is what I recommend across the board. See comments]  I cringe when I think how I’ve had my own past “hammer” of one sort or another and sought to fix everyone’s problems with it. So when we have only one answer to a problem, then we hear it’s not working e.g. ‘low carb’ isn’t working for some-one, we think “they’re not doing it right” or some version of that. Or perhaps we hear that someone added in more carbs and their weight loss increased and their health improved. If it doesn’t fit for us – we then ignore it or try to rationalise it somehow.

Take my Zone days for example – I thought all anyone needed to do was go on the Zone diet and their problem would be solved. Very low carb was incorrect – the body is forced to release cortisol for gluconeogenesis (not good). High carb was also wrong as it caused excess blood glucose and consequent insulin release, and then fat storage and hunger. I got stuck for a while in my view that the Zone was the only way to go.

At University I was given this review article:

Dietary composition and weight loss: can we individualize dietary prescriptions according to insulin sensitivity or secretion status?


Division of Endocrinology, Diabetes and Metabolism, Tufts-New England Medical Center, Boston, Massachusetts 02111, USA. apittas@tufts-nemc.org


There is considerable uncertainty over whether any one dietary pattern broadly facilitates weight loss or maintenance of weight loss, and current dietary guidelines recommend a spectrum of dietary composition for the general population. However, emerging evidence suggests that specific dietary compositions may work better for identifiable groups of overweight/obese individuals based on their individual metabolic status. In particular, characteristics of insulin dynamics, such as insulin sensitivity or insulin secretion status, may interact with diets that vary in macronutrient composition to influence the weight loss achieved with a hypocaloric diet.

If you do have access to the full article – it has a useful discussion on the complexities of insulin secretion, insulin sensitivity, insulin resistance, fasting insulin vs post prandial insulin… (I.e. there is more to the picture than high carbs = high insulin = fat gain)

One studies it referred to was this one:

Obes Res. 2005 Apr;13(4):703-9.

Insulin sensitivity determines the effectiveness of dietary macronutrient composition on weight loss in obese women.


Department of Medicine, University of Colorado Health Sciences Center, Denver, CO, USA.



To determine whether macronutrient composition of a hypocaloric diet can enhance its effectiveness and whether insulin sensitivity (Si) affects the response to hypocaloric diets.


Obese nondiabetic insulin-sensitive (fasting insulin < 10 microU/mL; n = 12) and obese nondiabetic insulin-resistant (fasting insulin > 15 microU/mL; n = 9) women (23 to 53 years old) were randomized to either a high carbohydrate (CHO) (HC)/low fat (LF) (60% CHO, 20% fat) or low CHO (LC)/high fat (HF) (40% CHO, 40% fat) hypocaloric diet. Primary outcome measures after a 16-week dietary intervention were: changes in body weight (BW), Si, resting metabolic rate, and fasting lipids.


Insulin-sensitive women on the HC/LF diet lost 13.5 +/- 1.2% (p < 0.001) of their initial BW, whereas those on the LC/HF diet lost 6.8 +/- 1.2% (p < 0.001; p < 0.002 between the groups). In contrast, among the insulin-resistant women, those on the LC/HF diet lost 13.4 +/- 1.3% (p < 0.001) of their initial BW as compared with 8.5 +/- 1.4% (p < 0.001) lost by those on the HC/LF diet (p < 0.04 between two groups). These differences could not be explained by changes in resting metabolic rate, activity, or intake. Overall, changes in Si were associated with the degree of weight loss (r = -0.57, p < 0.05).


The state of Si determines the effectiveness of macronutrient composition of hypocaloric diets in obese women. For maximal benefit, the macronutrient composition of a hypocaloric diet may need to be adjusted to correspond to the state of Si.

[NOTE: An important point to note is that any diet that is calorie reduced is likely to reduce carbohydrate calories from previous intake, so don’t make the assumption the these women increased their carbohydrate intake from their pre-diet one. The calorie reduction was 30% – so carbs could potentially be 30% less than previous intake]

I have to say at the time I was SO entrenched in low/moderate carb i.e. Zone diet was “THE RIGHT WAY TO EAT” I actually couldn’t get my head around the fact that this study showed that when two different calorie reduced diets were tested some women lost more weight on the higher carb diet. Significantly more than they did on a higher protein, lower carb diet.

My point? Let’s not assume that our “hammer” i.e. what has worked for us is the best answer for everyone else. Their body may run very differently from our own, and a like this study shows may run better on a very different mix of fuel.

Be aware that what has worked for you has highly coloured your world view. Try and put it aside, and you might discover that what the other person needs a screwdriver. Or when they say they are losing weight eating more carbs rather than less, they are not deluding themselves.

More reading: Lyle MacDonald discusses insulin sensitivity and fat loss in this 2008 article: Insulin Sensitivity and fat loss.


  1. I still maintain that “the fix” for many people, is less about what they end up eating… whichever dietary paradigm they follow, but rather what they stop eating, or at least eat a whole lot less of. It gets really tiresome watching all the pissing matches unfold; seeing countless pages on the interweb dedicated to arguing and armwrestling over differences between high carb paleo, low carb paleo, or even paleo vs. veganism… is it the carbs? Or is it the fat? When ultimately, you see a massive amount of improvement when people make changes that span all of these paradigms. They either eliminate, or, at the very least, severely restrict the combinations of grains, industrial oils, fructose, and soy, and they alter many of the lifestyle factors that go with SAD eating and living. These changes alone induce a massive alteration in people’s health. Yes, I’ll argue that paleo will take this a step further, but that’s “my hammer”. But regardless, the reduction of dietary toxins, a common feature of many diet, gets the most traction.

    • I agree “Paleo” (damn-it, even that term is becoming almost a cliche) i.e. taking the foods out of our diets that are messing with the human animal, is by far the most critical part of the picture.
      After that it is a matter of tweaking to find what works for us as individuals. I don’t want to get into the high carb low carb debate. My point is that we each need to find what works on that continuum for ourselves, and, due to changes or improvements in insulin sensitivity, insulin secretion, etc. it’s possible that it could change over time. The point I’m trying to make is – don’t inflict what works for you on others like that is the only way to go, and don’t think that the only way people lose weight is low carb. This small study shows otherwise.

      I cannot imagine I’ll change from the “take the toxic crap out of your diet” hammer / paradigm, as my first and major message. But I’m sure there will be tweaks and new discoveries that will alter that message a little.

  2. Low carbing did three things for me.

    1. It cut out grains.
    2. It cut out sugar.
    3. It led me to Paleo.

    I’m now doing 200 to 250g a day of carbs and am doing much better than when low carbing. I don’t crave cheat meals, am losing weight and doing better on workouts.

    Having said that, I’m sure low carb works for some people. But the toxic sludge is much more important to remove.

    • Thanks for sharing your experience – I think low carbing has worked / does work for many for these very reasons you state – it cuts out grains – and in particular the gluten grains, so many have undiagnosed gluten intolerance / sensitivity. And the sugars, and in many cases steers people towards natural animal fats.

      I know the Zone diet did the same for me – although it took me years to realise it was the grains that were the problem. It wasn’t the “magic ratio” of protein / carb / fat that gave me the primary result. Not to take away from that – less carbs and balanced meals helped solve my blood sugar and weight issues and gain better appetite control, and still do.

      So many people like you and I would then swear that low carb / or zone / or raw vegan / or blood type diet (I’ve seen the same “I’ve seen the light” experience from all of these) is the answer – when all along – like Jamie pointed out – it’s the removal of toxic food that made the difference.

  3. Interesting post Julianne, thanks. I’m someone for whom low carb didn’t work in any way, and am often told, pityingly, that I obviously wasn’t doing it right, lol. Those are the people bashing me about the head with their particular hammer (great, now I have a completely new mental image to make me laugh!), which means it can be hard to find a way through all the different views. Everyone is so sure they’re right! That’s especially so when you have Robb Wolf scoffing at the ‘snowflake’ idea that we’re unique. We are unique; you’re absolutely right that there isn’t a single answer for everyone, but he’s also right that there are universally helpful steps to take to get good health outcomes – I include mental health in there. I’ve just been reading Kurt Harris’s latest comments, and find myself agreeing that the removal of toxins is more important than any other factor, then the tweaks for individual wellbeing come after that. So I come back to my original point, which is that this was a timely and nice contribution to the discussion!

    • Thanks Jac, it is interesting to go through a whole raft of trials before we find what works for ourselves.

      There are so many ‘guru’ types in the nutrition field it can be daunting finding ones own way – which sometimes is at odds to what the ‘experts’ are saying.

      Personally I’m still experimenting! I’m going to try the Wahls diet version next – which will up my plant foods quite a lot. I’m interested to see what this will do for me. I’ve ordered her book.

      • I’ll be interested to see how it goes. My next venture will be IF the Perfect Health way – lots of coconut oil and a small eating window that includes carbs. After Christmas seems like the time to try it – low stress, lots of sleep and sun – bring it on!! Have a great Christmas

  4. @jac – pre-christmas is actually the good time to go IF (with an appropriate window) – allows you to eat a bit more of the nice stuff without going overboard 🙂

    @julianne – nothing really to add rather than full support; most if not all people could benefit from cutting out the cr+p from their diets. everything else is highly individual, maybe driven by genetics, or maybe by early (reversible or irreversible) priming – who knows for sure? (this question is rhetoric – my money is on “no-one”…)

  5. Am I the only one who’s noticed that 40% carbs is not a “low-carb” diet by any definition?

    Also, since I don’t have access to fulltext, can someone elucidate what the fat sources were in the 40% carb “low-carb, high-fat” diet? For that matter, some clue about the compositions of the diets in general? A diet of 40% soybean oil is not equivalent to a diet of 40% butter and beef fat.

    I’m sure fulltext would answer some of these questions — but the abstract leaves me without enough information to draw any conclusions.


    • Yes – as is typical in these studies – they call it low carb because it is tested against the ‘normal’ recommended diet which is 55% approx carb.
      The low carb diet is in fact, by my definition would be moderate carb – Zone diet ratios.

      I agree it does need to be pulled apart some more. I’ll take a closer look at the info I have.

  6. Someone’s developed a genetic test that purportedly identifies the best weight-loss diet (low-carb vs low-fat) for an individual’s metabolism. I blogged about it last year: http://advancedmediterraneandiet.com/blog/2010/05/25/individual-response-to-weight-loss-diet-may-depend-on-genes/
    The test costs about $100 (USD).
    I think I’d prefer to keep my $100 and just experiment for 4-6 weeks with each type of diet. (But I already know what works best to keep my weight reasonable: low-carb.)


  7. I’ve been keeping track of my carbs and calorie deficits since going 95% strict Paleo on March 4th of this year. I didn’t really focus on the diet as low carb rather as low inflammation getting rid of all grain based carbs, sugar, dairy and trans fats. To date I have lost 34 lbs going from 213 down to 179 in 76 days. I just did an analysis of my average daily carb intake and it came in at 86 g per day. Probably a low/moderate range. This is a level I just evolved to without any effort and it has worked great for me. For what its worth I suggest people not focus on carbs but on avoiding those foods that cause inflammation. Feel free to visit my Paleo diary on Facebook for more details.


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