The FastDay Forum

Trying to tease out the differences between regimes on approximately comparable studies. Spreadsheet here

The best results in terms of effective calorie deficit (calculated from the loss of fat and fat-free mass) were from ADF of 125 / 25% of calories using either high or low fat diet. ADF using liquid meal replacements was the next most effective.

Harvie's original 5:2 with 2 consecutive "milky" low calorie diet days was a long way behind, although the dieting period was much longer.

Comments and observations ?

Hi PhilT

Just a quick observation, The units for fast calories where of 2 different types that makes comparisons difficult Some figures are in % others not. If this data could be clean you may have a better chance of differentiating the overall results.

Not an expert but thought I'd have a look.

Hi Phil,

In the first paper listed in your spreadsheet there is the comment that "Fat Free Mass remained unchanged" - but the sheet shows an increase (which I would not have expected without exercise) - what am I not understanding?

Pete

I haven't looked at the paper and spreadsheet yet...need to get to the PC, but my guess is that the change was not statistically significant.

CreakyPete wrote: In the first paper listed in your spreadsheet there is the comment that "Fat Free Mass remained unchanged" - but the sheet shows an increase (which I would not have expected without exercise) - what am I not understanding?

The numbers in my spreadsheet are correct - this is usually the case with me as words aren't my thing

There are some wrong numbers in the tables in the paper - well at least one. The "no change" may have been Not Significant.

jacquiann wrote: Just a quick observation, The units for fast calories where of 2 different types that makes comparisons difficult Some figures are in % others not. If this data could be clean you may have a better chance of differentiating the overall results.

Data not available or specific to individuals - most of these trials feed people their baseline calorie needs as 100% and apply redcutions to that level, so the actual calories would be a range and often isn't reported.

It's frustrating that no-one is doing it like we are! The nearest is the 2-day diet but the consecutive days and the milky diet may add confounding factors.

One interesting thing though is that compared with the progress tracker results, the ADF figures are not any better in kg/week lost but the 2-day diet is considerably worse. Of course our data is pretty 'dirty' but involves large numbers of subjects for whom the average starting BMI is actually probably below 30 whereas the 2-day diet study involved women with a BMI of 30.

I just interrogated the progress tracker and got the loss for women who started out obese (i.e., >30) doing 5:2 and have been following the diet for 1-3 months (median 6.5 weeks) and the result is a median weekly loss of 0.66kg (n=60) with a mean total loss of 4.65 kg), which is pretty similar to the ADF studies.

If you look at the calorie restriction over the week, doing ADF on 125%/25% gives a weekly calorie deficit of 25%, whereas doing 5:2 on 100%/25% you get a weekly calorie deficit of 20%, so its hardly surprising that it makes little difference (PhilT, just check my calculations here!).

20% is too round

550/7 = 78.6 so 21.4% which if anything reinforces your point.

Thanks

It looks like it's not worth the hassle of doing ADF unless you can keep your feed days to 100% rather than 125%, but the changes in the hypothalamus etc may result in too big a pressure on appetite to keep to 100%. Would be interesting to know how the ADF/4:3 people are finding feed days.

I think you're all just too clever!
I appreciate all the research and analyzing that you do, and the contribution you make this forum what it is.
Thanx.

I added the 2-day diet (Genesis breast cancer carb restricted 2 days/week)

CreakyPete wrote: Hi Phil,

In the first paper listed in your spreadsheet there is the comment that "Fat Free Mass remained unchanged" - but the sheet shows an increase (which I would not have expected without exercise) - what am I not understanding?

Pete

Extract from full paper :-

Body composition was also favorably altered with both diets. To elaborate, fat mass decreased to a similar extent in the ADF-HF group (5.4kg) and the ADF-LF group (4.2kg). As for fat free mass, non-significant increases were noted for both the HF diet (0.6kg) and LF diet (0.5kg). These data suggest that the weight loss observed with ADF results from a decrease in fat mass, and not fat free mass. A similar preservation of lean mass (0.5kg) was noted in a previous ADF study conducted by our group [15]. Interestingly, this retention in lean mass observed with ADF is not replicated with CR diets. For instance, consistent reductions of 3%–5% in fat free mass are generally noted after 8weeks of 25%–40% CR [16], [17]. The reason why ADF may assist with the preservation of lean mass is not known at present, but will undoubtedly be of interest in future studies in this field.

I was going to reply to a couple of the post where people were saying that they were going to do more fast days and say that my experience of ADF is that I'm losing weight at the same rate as the 5:2ers. But then that's just my experience so felt I shouldn't say it, so it's nice to have some confirmation that I'm similar to other people.