The FastDay Forum

Hi all,

A different take on the calorie can be listened to here: http://www.bbc.co.uk/podcasts/series/foodprog/all, this programme puts the Dreaded C-word in some perspective. You need to scroll down a bit to find the correct episode, which can be downloaded onto your i-pods or -pads or whatever these contraptions are called. The same page (site?) contains interesting downloads on fermentation, kefir, yoghurt, agricultural policies and the like. Enjoy!

http://downloads.bbc.co.uk/podcasts/rad ... -1630a.mp3 direct link

Part of the Fundamentals of Human Nutrition course

Still believe a calorie is a calorie? : Robert Lustig MD

http://www.huffingtonpost.com/robert-lu ... 59564.html

[Betsysgr8]

Very interesting thread.

Wow! Thanks for the info!

Well I found it a rather frustrating radio programme. Far too much of Zoe Harcombe spouting drivel (sorry my opinion). The section tackling the 3500 calories = 1 lb of weight approximation was especially absurd IMO.

The conclusions - eat less carbs especially the sugars, eat more nuts, green veg, oily fish etc, are fine, but what had this to do with the central hook of the programme - that calories don't matter? I think calories do matter, they are just not the only thing that matters.

It is true that our '5:2 diet' has only one absolute requirement and it is a calorie restriction. But I hope all of us realise that a healthy diet is about more than that. One of the really good things (perhaps even the best) about 5:2 is that it encourages us to eat more healthily so that we can get the most sustenance out of our 500 or 600 calories on those fast days. Hopefully that then impacts at least to some degree on what we eat on the 5 days too. It has for me anyway.

Thanks for the summary on the radio program Dominic. I tried to listen at work but there are just too many distractions and noise so I gave up. I did read the Huffington article Navwoman posted which I thought was very enlightening.

dominic, I agree with your summary (thanks), but all this talk about calories, the whole TDEE-thing sometimes creates the impression that it doesn't matter where your calories come from ie junk or healthy foods. Also: the whole idea that 3500 kcals equal 1 lb of human adipose tissue seems a bit arbitrary. I found it enlightning to hear confirmed something that I had noticed before: that it's the carbs rather than the fat that makes you overweight, contrary to Dutch government guidelines and contrary to what many diets want you to believe.

Also: the whole idea that 3500 kcals equal 1 lb of human adipose tissue seems a bit arbitrary.

It has been validated in practice on many occasions, within experimental accuracy. If you take 0.8 lbs of fat and 0.2 lbs of protein it equates to 3632 kcals.

I agree with PhilT (from whom I first heard of this approximation) that 3500 kcal/lb seems a pretty good rule of thumb. It also fits pretty well with our own Tracker results.

I found a paper here which looks at it in more depth. Pure fat in the body contains energy @ 4280 kcal/lb (39.5 MJ/kg). (Note: adipose tissue - our fat deposits - also include roughly 15% water and 5% protein too.) Protein contains 2130 kcal/lb (19.7 MJ/kg). And weight loss also involves loss of water and (though it is only considered significant in the early stages of weight loss) glycogen.

The protein energy measure needs to be adjusted by a 'protein hydration coefficient' which the writer of the paper estimates at 1.6 g water per g protein, so this reduces the net energy per lb of lost FFM+associated water down to 820 kcal/lb (7.6 MJ/kg).

Assuming this deals with the water issue and ignoring glycogen, that leaves the issue of how much weight we are losing as fat and how much as FFM (in effect, protein+water).

I think it is normally assumed that one loses about 70% fat and 30% FFM, which would on these figures give a weighted average of 3240 kcal/lb. However Dr Michael Mosley has stated (based I think on the ADF studies of Dr Krita Varady) that with IF (including, we hope, 5:2) up to 90% of the weight loss could be fat. This would imply lower weight loss because fat is a more dense source of energy that FFM: we would need to save 3930 kcal/lb. Neither of these figures are too far away from the 'rule of thumb' 3500 kcal/lb. So I think it is still usable.

I found it enlightening to hear confirmed something that I had noticed before: that it's the carbs rather than the fat that makes you overweight

That may be true but not I think for the reason you imagine. It is quite possible to get fat by eating fat or protein, it is just that people tend not to gorge so much on these unless they are combined with carbs especially sugars. That is why having a lot of high GI carbs in the diet is so bad - it encourages feasting and hence taking in too many calories.

The converse is also true: it is quite possible to get thin on a high-carb diet and indeed most successful dieters have done so, and continue to do so. The anti-carb argument is that this is a much harder and (controversially) less healthy way to lose weight than by following a higher-fat calorie-restricted diet.

There is no way that one will convince me that calories don't matter or that carbs make us fat.
One of the easiest ways to lose weight is to eat a plate of rice for lunch and a plate of rice for dinner. It's what we eat WITH carbs that does all the damage. Sure carbs won't get me fat but if the carbs I eat is pizza with garlic bread and a big ice cream for dessert, then, well, you know...

The much-vilified Robert Atkins points out that one of his clients hardly changed his calorie intake, from 2127 a day to 1930, when doing the Atkins diet.

He went from gaining 2 pounds a month, over a period of 35 months, with his old way of eating, to losing 4 pounds a week over the first 3 months on Atkins.

The number of calories are irrelevant. It's the source of them that matters. Low-carb foods can be laden with calories, but weight can still be lost.

To be honest tomtank I don't believe it, and if it is true I would be interested to know more. (I don't mean that Dr Atkins didn't say it, only that it didn't happen that way.) I thought it was generally accepted that, whatever may have originally been claimed, the Atkins diet worked by calorie restriction - when people cut out carbs they just couldn't eat so much. I know it worked that way for me.

If it is true, how does it work? Where does all the energy go?

Τhere have been a number of experiments during which people lost weight by eating pizza, burgers, even Mars bars daily because they ate less calories than their TDEE...

I wouldn't trust Mr Atkins and the the success stories of his diet since I know that he is only trying to sell.

I lost 15 kilos doing Atkins, and was able to enjoy vast quantities of food, albeit low-carb ones!

I still follow Atkins on my non-fast days, and am really only doing 5:2 for the added health benefits.

On NF days, I eat a lot of cheese, butter and cream, and never cut the fat off meat. One added bonus, on Atkins, is that hunger pangs are non-existent.

I have never calculated my calorie intake on non-fast days. I will do that, though, to prove my point!

Being on Atkins never diminishes my appetite, so I am able to really indulge when not fasting.