Low-carb diet again trumps low-fat on weight loss and other things

While some see body weight as simply a function of the balance of the calories going into and out of the body, there is little doubt in my mind that this stance is becoming increasingly untenable. It is clear that body fat regulation is influenced by many factors, including levels of key hormones. A central player here is insulin – which encourages fat deposition. But other hormones worthy of mention include what are termed ‘adipokines’ (secreted by fat cells). One important adipokine is leptin. In March, I wrote a blog post dedicated to this substance which was inspired by the work of Dr Stephan Guyenet who writes the blog Whole Health Source.

Another adipokine that has received increasing attention in recent years is adiponectin. Like leptin, adiponectin has generally beneficial effects in the body. It, for instance, has anti-inflammatory effects and helps maintain ‘insulin sensitivity’. Both of these effects would be expected to translate into a reduced risk of type 2 diabetes and heart disease. The actions of adiponectin in the body are believed to offer protection again these conditions, as well as others including obesity, ‘fatty liver’ and metabolic syndrome. In short: adiponectin is a good thing.

When individuals lose weight, adiponectin levels tend to rise. Generally speaking, the more adiponectin levels rise, the better. Remember, higher adiponectin levels are associated with beneficial effects and protection from chronic disease.

I was interested to read a recent study in which obese women were randomised to a diet either low in fat or low in carbohydrate [1]. After 4-6 months, weight loss on the low-carb diet was significantly greater than on the low-fat regime (average loss of about 9 kg vs about 5 kg). Fat loss was also much better on the low-carb regime (about 5.5 kg vs about 2.5 kg). This study reflects wider evidence which deomnstrates that, overall, low-carbohydrate diets trump low-fat ones in terms of weight loss.

However, in this study, adiponectin levels were also assessed. Importantly, these rose significantly in those eating the low-carb diet. This was not the case for those eating ‘low-fat’. It’s perhaps worth bearing in mind that compared to low-fat eating, low-carb regimes improve a range of other disease markers including blood pressure, triglyceride levels, ‘healthy’ HDL cholesterol levels and blood sugar control.

References:

1. Summer SS, et al. Adiponectin Changes in Relation to the Macronutrient Composition of a Weight-Loss Diet. Obesity (Silver Spring) 2011 Mar 31. [Epub ahead of print]

9 Responses to Low-carb diet again trumps low-fat on weight loss and other things

  1. Chris 31 May 2011 at 8:51 am #

    It is interesting that in his most recent posts
    Dr Stephan is stressing the role of food reward and the impact on leptin, but that he is somewht ambivalent about low carb vs low fat. He promotes real food, home prepared, but not necessarily low carb. His interview on the Healthy Skeptic podcast is fascinating and in it he outlines his own diet which is built around lots of spuds!

  2. Catherine 31 May 2011 at 4:07 pm #

    Great posts! Do you think that the extent of glucose intolerance in a person affects the degree to which they may benefit from a low carb approach and that the majority of the population are heading in this direction? I certainly like the reward hypothesis as it makes so much sense and indeed paleo eating with a low reward value seems to result in people simply eating less. However paleo is not always practical in every day life, whereas low carb eating is! Even then can a glucose intolerant person manage a load of potatoes when other modern day factors are consipiring against them such as high caffeine and stress contributing to say insulin resistance?

  3. John Briffa 1 June 2011 at 6:50 am #

    Catherine

    Do you think that the extent of glucose intolerance in a person affects the degree to which they may benefit from a low carb approach and that the majority of the population are heading in this direction?

    Yes and yes.

  4. kate 4 June 2011 at 12:41 am #

    I’m guessing that caloric restriction did not occur in the low-fat diet to the same extent as in the low-carb diet. The only reference to actual caloric intake of either group was reported dietary records – a few days worth. Caloric restriction raises adiponectin levels, and it’s been shown in many low-carb studies that low-carb diets reduce calorie intake.

  5. John Briffa 4 June 2011 at 8:28 am #

    Kate

    it’s been shown in many low-carb studies that low-carb diets reduce calorie intake.

    Yes, precisely. And critically without conscious restriction of calories.

  6. patricia 4 June 2011 at 8:58 am #

    in desperation I tried a low-carb diet a few years ago (Atkins), not only did it make me feel ill, it didnt result in a single ounce of weight loss. I followed it to the letter as well!

  7. Florence 4 June 2011 at 5:47 pm #

    Am I right in thinking that Atkins was no carb rather than low carb and that this is not really the way to go? Eating low carb, and much more frequently, did the trick.

  8. tess 19 August 2011 at 1:56 am #

    Florence, i could run screaming into the night, when i think about the media convincing people of this nonsense. :-) Atkins is far from no-carb. the biggest problem with it is the “neolithic agents of disease” it encourages, like soy, and various processed non-traditional “food-like substances”.

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