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The 5:2 Lab

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Hi Madge! Funny you should mention that...I was just thinking it should be added as I believe that people with a recent dieting history are slower to lose weight. It was about 10 years since I last dieted and the weight has been dropping off me despite me being sedentary! I would never eat low-fat etc diet type foods beforehand either which again may be relevant. I'll add your thoughts to the plan!
Great minds think alike! I don't think it's just recent dieting history with me though. Even in my 20's I had to make a special effort just to remain in the top end of my 'normal' weight range. Roll on twenty-five years and things don't get any easier. It's led me to have my thyroid tested a few times over the years - but it always comes back annoyingly normal!
I have found this very interesting to read (if a little over my head) :bugeyes:
I was wondering though, if you should also ask about whether people are taking any vitamin supplements as part of their daily routine as I have read some articles that suggest vitamin B (specifically B7 I believe) can affect the metabolism?
Very interesting thread and I'll happily cooperate with any efforts you make to study these factors but I have serious concerns about the calorie data you collect.

Back in Feb I asked about the accuracy of calorie figures given on food labels and I think the consensus was that they were allowed to be sort of right - within a range of 25%.

Given that supermarkets' marketing departments have every incentive to understate calorie content the chances are that supermarket meals labels under record calories by 10%-15%.

Leaving that aside I only have a vague idea about how I would calculate the calorie content of home cooked food with anything like reasonable accuracy.

Indeed it seems to me that one of the strengths of this diet is that there is no need to count calories on feast days and personally I've chosen to go for as close to zero as possible on fast days.

The conclusion I draw from this is that calorie counts given by people for what they eat are not likely to be much better than an honest but educated guess. Certainly they are unlikely to be accurate to within 10%.

The calorie restriction in 5:2 over a week is approx 20% so I don't think it unreasonable that people's rate of weight loss is fairly variable.

Then there are all the other factors that have been mentioned.........

Another thought - It's taken me 15 years to get to being obese. It would be wholly unreasonable for me to expect to regain reasonable shape in anything less than a year to 18 months.
You are right of course about the inaccuracy of our calorie estimations. It is likely to be underestimated. However, my TDEE is supposed to be variously, 1900, 1750, or 1654 depending on the calculator. My guesstimate of calories consumed is around an average of 1500 per day including fast days (probably more than that as we know), most feed days I'm up to the 1900 mark and yet I have lost nearly 1kg per week. The maths doesn't add up!

So I think we may not need to be that accurate. In fact what might be relevant could be whether people think they are restricting on feed days, because what goes on in the brain is important to weight loss/gain, appetite etc.
I have lost nearly 1kg per week. The maths doesn't add up!
Do you have two measurements from the doctors scale to validate the loss ? I think you said something about weighing there being several kg different to at home.

If it isn't the scales, then a calorie is not a calorie when it comes to weight loss :oops:
Yes, I do actually...105 kg before starting, 90 kg a couple of weeks ago so that's 15kg, which agrees with the change on my scales if not the actual numbers on the dial! But thinking about it, even if the scales are not accurate in the absolute reading the change is going to be valid. If the scales are 10% out (which is what they seem to be) then a change of 18kg would have an error of 1.8 kg, which still does not add up correctly. I have been doing 5:2 for 20 weeks with 2 weeks off over Xmas with no weight loss. So 18 weeks = 18 kg or even 20 weeks = 16kg, it's still more than the apparent energy balance suggests.

I have pondered on this for quite a while. It seems odd that metabolic differences could add up to so much but perhaps they can.

Factors that might result in a higher TDEE than estimated:
higher lean mass due to large muscles? (but my estimation of body fat using the skinfold thickness method and the tape measure method suggest that %body fat is approx what the TDEE calculators assume)
Freezing cold house?
Perhaps the HIIT protocol does more than we think - the exercise bike says it uses a huge 25 cals! (but I didn't start that until halfway through those 20 weeks)
Greater NEAT than expected? (but I do sit on my backside at the computer most of the day as you can tell from how much I'm on the forum!)
Insomnia resulting in more thrashing around in bed burns up a lot of calories? (seems unlikely as that has been the case for ages and I would not have been obese in the first place)
Over-active thyroid? (again unlikely as I would not have been obese, I have no symptoms either)

Factors that might result in a lower calorie intake than estimated
Um, I'm unusual in my reporting behaviour by over rather than underestimating?
Free-range/organic eggs, milk etc contain fewer calories than the standards I'm using for calculation? (extremely unlikely)
Some kind of digestive change resulting in fewer calories being absorbed from food that has been triggered since starting 5:2?

So this leaves us with the conclusion that a calorie might not necessarily be a calorie! This is one reason why I'm so keen to find out what links the other people who have had a good weightloss.

Did you see that paper which suggested that some people do better on low fat diets others on low carb diets and that the difference in weight loss could be as much as a factor of 2? Perhaps it is the balance of carbs and fats (or even fibre) in the diet which needs to be personalised? A lot of people on here are still eating diet food, especially on fast days, which I don't. Perhaps it is the 24 hour fast that gives some benefit. Perhaps it is the fact that I hadn't been on a weight loss diet for around 10 years.

Still enough about me! I'm not the only one with good losses to show. I wonder if Moogie could extract the ranges as well as the medians from the progress tracker? That might give us some interesting info.
Just a little addition to the above! This is the progress tracker data for people like me:

51 forum members matching your selection are tracking their weight loss progress, 47 of whom have lost a total of 235.79kg over a combined total of 369 weeks and 5 days (mean average 7 weeks 6 days).
This is a mean average of 0.637kg lost per member per week (median 0.567kg).


Whereas for me:
You've lost 17.8kg since starting your diet 19 weeks 2 days ago (your start date to last recorded weigh in). That's a mean average of 0.923kg lost per week.
And there's more!

I just found an online bodyfat calculator which gave an estimate of 34% fat (based on waist measurement) so I plugged that into the Katch-McCardle formula to get a TDEE of 1766 if I am sedentary or 2023 based on exercising three times a week. So could it be that the HIIT protocol burns a lot more than one would expect from the 5 minutes I spend on it three times a week?

We should certainly ask about this in the questionnaire!
This so interesting - sorry I haven't actually read all posts in the middle so apologies if I repeat something.
I have not joined the progress tracker at the moment, but can report average losses of about 1 lb per week on 4:3 simply because I still overeat on food days. Portions are under control but snacks are not (yet)

It would be so exciting if you could crack this nut - however what I see as your biggest stumbling block is recording actual reliable intakes from a large enough sample. I just read the Robert Lustig article in the Guardian this morning - though I was aware of that whole sugar-related research. And I think there is is mentioned that the problems with volunteers' food diaries are many fold, under-reporting and under-estimation being the main one of course, but quite a few others I had never considered. Short of incarcerating your subjects and catering for them for prolonged periods it's just not possible. So you are relying on perceived and self-reported data on consumption and exercise etc. TDDEs can be calculated though it would appear that even there we have no certainly. Personally I work with a sedentary TDEE and then add my exercise on top - I do cycle to work for example but I don;'t work every day and so on.

What you found with HIIT is probably true though.
I think that we have to assume that the under-reporting/over-reporting will be broadly similar across people (I big assumption I know but as you say without incarcerating people in a lab there is no choice). If we take the top and bottom quartiles of weight loss we will, hopefully, be comparing a group of people who mis-report with another group that similarly mis-report! Similarly if we calculate the TDEE using a standard formula for everyone (or even use several TDEE calculators) again the error will be similar in both quartiles.

It is quite likely that there will be just too much noise in the system to find any statistical differences, but without trying we'll never know. Even a trend would be worth finding because people who are struggling could at least try to change what they are doing and see if it works!
I fiddled around with your data hoping for a bright light to come on, but was disappointed.

You did report intake around 1400 or less for three weeks, and the Christmas period gain was modest compared to the stated intake (resulting in a very low TDEE estimate).

With my smoothing "adjustments" your median TDEE is 2628, for what its worth.

You need someone to send you some doubly labelled water ;-)
Hi.Would it be possible/of any scientific use to track what those of us who have a BMI under 25 are getting up to, as well, please? I need/want to lower my "fat content" and would be very grateful for any additional tips which would help me to lose weight more effectively. As others have said it's pretty clear that weight loss becomes slower as people near their optimum weight so loss becomes harder for everyone as progress is made, and any little tips might help. :heart:
I really think we need to make the attempt to find out if there are any factors linking the big losers that are not found in the little losers as we are getting more and more posts from people who are getting very poor weight loss.

I will put together a questionnaire and ask for volunteers!
I have made a stab at a questionnaire: http://dl.dropbox.com/u/32116230/52fast ... naire.docx

Please review and tell me what to add/remove!
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