The FastDay Forum

I was talking to somebody who is doing the fast diet and she said her friend has been doing it for a while but she starts her 24 hours after lunch. Basically she has a proper lunch and then has 500 calories between then and lunchtime the next day so you only have one dinner and one breakfast for 500 cals. Apparently it works just as well and she has been loosing a pound a week.

Has anyone heard of this or experienced in themselves? I would be interested in hearing back from others.

Currently I fast Wednesday and Fridays.

Graeme

Seems to be alot of variation in ways to do it from what I am seeing, but as described above, she is actually 1000 calories on her fast day because she is doing 500 at dinner and 500 at breakfast the next day, so it isn't really the same thing as 5:2.

I had a go with a graph to compare regimes :-

[carorees]

Goodness, this is getting technical!

In the end, we all agree that the calorie deficit over the week is what controls weight loss while having long periods without food or minimal food seems to suppress appetite and may bring other benefits too (as yet unknown to what extent). For most, the simplicity of only having to count calories on the two fast days is preferred, but as long as the basic precepts are followed, you can design your own system. And many have.

Fasting lunchtime to lunchtime will work fine as long as the calorie intake is low enough and there are some long food-free periods.

With your graph, I'm not sure of the relevance of comparing mid-night to mid-night calendar days when mid-night doesn't coincide with any calorie intake event or the start/end of a calorie deficit period.

Thanks for the graphs, I did one on an hourly basis which got even more involved. Your variant with a bigger lunch and a cut back on the second dinner in particular.

I use midnight for a number of reasons, one being that it doesn't have much risk of clashing with a meal and getting embroiled in a "which day does this belong to" debate.

Secondly all of the clinical trials (which underwrite the concept of ADF and modified ADF) use calendar days, typically having no calorie intake after 22:00 sometimes earlier.

Thirdly their are circadian rhythms of leptin, thyroid hormones etc so "different things" are likely to happen overnight.

Fourthly at midnight people are usually in bed. So those are my reasons for considering a day as a diurnal / calendar day and not a sliding 24h window.

I'm also aware that some (not you) seem to take a 24 hour reduction as meaning a normal lunch followed by a normal lunch the following day (possibly an hour later) with 500-600 calories for dinner & breakfast. That runs the risk of having a much reduced deficit if (unlike you) lunch is the main meal of the day.

I agree that over a week you achieve the calorie reduction. So does someone cutting a percentage off every meal - continuous calorie control. However, as we know that continuous calorie reduction does not achieve some of the metabolic improvements, but ADF does, then we need to ensure that what we do or recommend is as close to the ADF protocol or modified ADF as tested as possible.

Of course if one is simply interested in calorie reduction then any changes anytime that add up to a weekly, monthly or annual deficit are fine.

The question is in my mind is their any evidence that two calendar days at 1,000 calories is a sufficient reduction to deliver the results that attract people to the 5:2 plan, especially the "health" benefits other than simple weight loss and things like retention of Fat Free Mass that is seen with a high restriction of calories but not with a moderate one.