I have since last June been undertaking a bit of a personal experiment. Over couple of years I’d found I’d somehow managed to accumulate some added fat to my midriff. At 43, I suppose ‘middle-aged’ spread might have had something to do with it. But also when I looked at my diet with as much objectivity as I could muster it became clear that crappy carbohydrates had crept in here and there.
Around this time I embarked on a book-writing project. The book (Waist Disposal – The Ultimate Fat Loss Manual for Men) is based on a wealth of available science as well as my clinical experience with real people in practice, and is due to be published next month. You will see from the title of the book that its contents had direct relevance to me. So, I resolved to take some of my own medicine. These are the two main changes I made:
1. I cut almost all starchy carbs from my diet, and ate even more ‘primally’ than ever.
2. In addition to the regular walking that I have done for years, I added just a few minutes of resistance exercise each day.
My rationale for the resistance exercise was nothing to do with ‘burning calories’. It was primarily to boost strength (never a bad thing) and to simply improve the look of my physique. I also knew that weight loss can induce not just loss of fat, but loss of a more desirable body element – muscle – too. Resistance exercise should help to preserve muscle during weight loss, which was another reason I engaged in this activity.
The results, even though I say so myself, were pretty dramatic. Monitoring my weight and skin-fold measurements (to estimate body fat) revealed that my body composition changed rapidly. I certainly looked quite different quite quickly. Plus, there was no doubt that I got stronger too. As an aside, I had an ambition of being able to perform 60 press-ups in a minute. I remembered being able to do this when I was at school. And school was about the last time I did any consistent resistance-related exercise (I was quite into gymnastics and gym-based exercise at the time). Seeing as I’d hardly done a single press-up over the last 25-odd years, I wasn’t too surprised to find that I could barely manage 15 of these back in June. However, over about a couple of months I was able to build up to 60 continuous press-ups which I have maintained since.
My book is geared towards men, but there’s no reason why the same principles may not help women too. And with this in mind I was interested to read a study published this week which tested the effects of a low-carb diet coupled with resistance exercise on weight loss and body composition change in women [1]. In this study, all women engaged in 60-100 minutes of varied resistance exercises twice weekly for 10 weeks.
Other than this, the group was split into two. One group ate a ‘conventional’ diet, in which calories contributed by carbohydrate, fat and protein were 41, 34 and 17 per cent respectively. The other group ate a very low carb diet in which calories contributed by carbohydrate, fat and protein were 6, 66 and 22 per cent respectively. You can download a provisional pdf of the whole study here.
The results?
On average, the conventional diet-eating group gained weight (an average of 0.8 kg – non-significant). This gain in weight appeared to be caused by an increase in ‘lean body mass’. Fat mass did not change significantly.
In comparison, the low-carb group did not appear to gain in terms of lean body mass. But they did lose a lot more fat: Average weight loss was an impressive 5.6 kg, ALL OF WHICH appeared to be in the form of fat. So, while this group of women did not seem to build muscle, they did not lose any either. Men have the added advantage of being able to preserve and even build muscle much more easily than women, generally speaking.
The results of this study demonstrate the potential fat loss benefits of a low-carb diet. They also support the idea that during weight loss, resistance exercise has benefits in terms of preservation of muscle mass. Previous studies have found that low-carb diets that lead to weight loss generally lead to muscle loss too. The preservation of muscle found in this study is likely to be down to the resistance exercise.
In short, a low-carb diet coupled with resistance exercise was found to be effective for fat loss and for the improvement in body composition. My forthcoming book – Waist Disposal – emphasises these approaches, and also includes a section on mental techniques that can accelerate the benefits to be had from diet and exercise.
References:
1. Jabekk PT, et al. Resistance training in overweight women on a ketogenic diet conserved lean body mass while reducing body fat. Nutrition and Metabolism. 2 March 2010;7(1):17. [Epub ahead of print]
Hi Jon
I know cutting out carbs works for me.
I have a question. I have an 8 year old daughter who has recently changed schools and has to have school lunches. She has seen putting on a lot of weight, mainly around her tummy and is quite a barrel shape.
I am clearly concerned that she does not get a complex, but I know it is effecting her ability to enjoy games and PE.
Is it appropriate to restrict her carbohydrate intake ? (Bearing in mind that I have no control over what she eats in school!)
Jan
But does one automatically lose muscle mass when dieting the low-carb way, if protein intake is sufficient?
For the most part, one might find oneself eating more protein than most people, for example through replacing cereals with protein food at breakfast, so I am quite surprised by this idea (altho’ I note that the women in that study did not lose muscle mass).
I found the Atkins diet to be tough (very) but also effective when I did it a few years ago but remember having problems with bad breath due to the ketosis. Is this always a consequence of low carb diets? I’m afraid to eat low carb because I don’t want to be self conscious about my breath. Grateful for advice.
As a woman I feel a bit left out!
I’m not surprised the women on the low carb diet failed to build muscle. We should remember that the brain and red blood cells cannot use fat or protein as a fuel and rely on carbohydrate under normal circumstances. With carbohydrate intake at 6% of daily calories the brain and red blood cells would be in short supply. The liver would set about rectifying the situation by converting amino acids found predominantly in muscle, such as alanine into glucose by the process of gluconeogenesis.
It’s misleading of Robin above to say the brain relies on carbohydrate as fuel. That’s not entirely accurate. What the brain needs is glucose. Several long-term studies (never mind the experience on wild animals) demonstrate the all that the brain needs can be gained from fatty meat. Carbohydrates really aren’t required.
Interesting study. A few limitations in it, but these are largely acknowledged by the authors. From my experience, I think that LBM increase in the high CHO group will be largely explained by an increase in glycogen storage (1g CHO is stored with 2.6g of water). Had an individual increased their glycogen storage capacity by 200-300g of CHO with the high CHO intake + training stimulus, they would have taken in at least another 500g on top of that.
Typcially, one would expect to account for approx one third of weight loss on a LC diet as loss of lean mass. The fact they didn’t lose this (and this matches up with my own personal experience – which actually mirrors Dr Briffa’s quite closely), shows that this isn’t always going to be the case (though time frames are relatively short in this study.
I think 20-25g of CHO is a very low intake and at those levels, the building of lean muscle mass would likely require a longer time frame than 10 weeks. And given that very few (if any) of the ‘Primal Bloggers’ advocate going low carb for short periods, I can’t see an issue with this.
I personally fluctuate between ~30g-100g on most days, depending on how much training I have done, and the type of training undertaken (I let it come up following resistance training but tend to hold it low following my cycling).
The lead author of the wonderful study you recently cited blogs here:
http://ramblingsofacarnivore.blogspot.com/
I’ll look forward to checking it out!
I’ve picked up a lot of information here that’s been really helpful, so I’ll definitely give your book a read.
Vit. D alone has made a huge difference for me. I live in the California desert and in the summer, the heat makes me somewhat housebound so that I used to get “cabin fever” by August. This year, no sign of it. So a huge thank you for that one alone!
Yet another short study (10 weeks) that really doesn’t prove anything. I am still waiting for a legit long-term study (18 months or more) that shows significant weight loss on a low-carb diet.
The existing long-term studies show that low-carb is the same as any other diet in the long run.
Robin said: “I’m not surprised the women on the low carb diet failed to build muscle. We should remember that the brain and red blood cells cannot use fat or protein as a fuel and rely on carbohydrate under normal circumstances. With carbohydrate intake at 6% of daily calories the brain and red blood cells would be in short supply. The liver would set about rectifying the situation by converting amino acids found predominantly in muscle, such as alanine into glucose by the process of gluconeogenesis.”
I think you have missed the point a bit with this study. The title reflects the findings… a CONSERVATION of LBM on a very low carb diet, whilst initiating and maintaining a resistance training programme. This flies in the face of convention dogma that would suggest that an individual would strip LBM at an accelerated rate in order to fuel, as you have suggested, gluconeogenesis in order to supply neural tissue demands. This study clearly showed that this wasn’t the case. LBM was protected. There appeared no detriment from following such a low CHO diet based on the parameters monitored. And as I have already posted, I suspect much of the LBM increase in the CHO group can be put down to maintenance of higher glycogen levels as you would expect.
The study was not a “lets see if we can increase LBM on a very low CHO diet” study. For a start, the training programme they were on was a bit rubbish for that sort of thing (as it invariably is with researchers writing training programmes for novices). And secondly, I don’t think that holding a CHO around the 20-30g mark would allow for the volumes of training needed to significantly boost LBM, at least not without bring protein levels up substantially higher (allowing for at least 2g per kg, the LC group was only consuming 1g of protein per kg – not too significantly different from the CHO group). Total fat intake could have been sacrificed a bit in order to boost protein intake.
And if sufficient substrates for gluconeogenesis are available, then I can see no reason why the body would begin to strip muscle mass for this purpose. And I suspect anyone who has experienced this in the past is guilty of stripping the CHO WITHOUT adequately replacing the energy with the other substrates (FAT + PRO).
Robin, the brain will never be in short supply of energy – it will always preferentially be allocated the fuel. Yes, your brain likes to run on glucose but once you are adopted on running on fat fuel the brain is very happy running on ketones (even happier than glucose).
Matt wrote:
“Yet another short study (10 weeks) that really doesn’t prove anything. I am still waiting for a legit long-term study (18 months or more) that shows significant weight loss on a low-carb diet.
The existing long-term studies show that low-carb is the same as any other diet in the long run.”
Matt, if you could provide references for the existing studies that you mention that do not;
a) Include those who dropped out of the study in the final analysis
b) Reintroduce CHO to the ‘low carb’ group
I would also take the view that if low carb diets are just as effective as the degeneration-inducing, metabolic destabilising, high carb diets, then it’s a no brainer. Same results, less side effects. Easy choice.
I have been taking a new advanced peptide technology in the form of powder which is based on whey protein. I have combined this with healthy eating following a low glycaemic regime and you are supposed to exercise. I can’t believe how it has changed my life. I guess I have lost about 2 1/2 stone and 7 inches around my middle. It targets fat and helps you build lean muscle so you tend to lose inches faster than lbs and I felt great whilst I was taking it. As I am 71 it is quite nice to have a waist again, in fact it has given me a new lease of life and I feel like a teenager – well not quite.
Hold your horses Matt. The study is what it is: it doesn’t claim to be a long-term study. Let’s face it, no research group is going to receive funding for a long-term research project without proving the concept initially in a short-term study.
One criticism of all calorie restricted diets and especially of low-carb diets is that some of the resulting weight loss derives from lean tissue. This study is very important for showing that in the low-carb group, almost every ounce of weight loss was due to fat loss.
This was despite the low-carb group eating much more fat but the same total energy intake as the standard diet group.
Let’s also remember that, as always in these studies, there was wide inter-individual variation in both total weight and body fat loss.
For me, it confirms that although we are all different, a low-carb approach to nutrition is, on average, the best approach.
could someone please tell me if bad breath is an inevitable side effect of low carb eating? It’s really putting me off embarking on it. Thanks.
Another interesting study from Australia shows that high protein (= low fat &moderate carb) diet together with resistance training will decrease fat mass more than high carb (low fat&moderate protein) diet together with resistance training (-8 kg vs -11 kg in 16 weeks), on similar energy deficit. (Wycherley TP et al. Diabetes Care. 2010 Feb 11.).
Similar difference was observed for total weight (-11 kg vs -14 kg).
Yet another observation from the same study, participants on high protein diet only (no resistance training) lost -7 kg, resistance training helped losing extra 4 kg fat mass. Resistance training with high protein diet (&low/ moderate amount of carbs) seems to be good option for body shaping.