For the science behind fasting try and find Michel Mosley’s Horizon programme 'Eat Fast and Live Longer' on You Tube.
It's true that more human trials need to be done to back up the claims that seem too good to be true but they might take a long time. One of the contributors to the documentary, who was researching dementia in mince though said in his opinion the current data suggested the implications for humans would be 'very good to excellent'.
As far as training goes if it’s true that fasting doesn’t reduce lean mass (muscle) then it seems better than constant calorie restriction. But I think you’d have to fast on rest days.
I have the same problem with either being strict or off the waggon, and I'd imagine a lot of others do too.
It's not easy and todays food culture seems based around cheap and seemingly addictive processed food and takeaways. I don't blame people (or myself) for getting fat with those pressures to contend with.
I don't think people today have any less willpower or are more lazy (even though there is more opportunity to drive rather than walk) than they were 30 years ago. The reason I believe there are 10 time more obese people and the average weight is rising is what we eat and when we eat.
I've restarted this week. I read on a forum something that sums up the thoughts above, someone said that 'fasting reset their apatite'. I also think that as you tend to take in lots of fluids such as fruit teas and water it helps flush out the system. Obviously high calorie alcohol is out which also helps cleanse.
It can be hard at 1st but in a strange way some people look forward to the fasting days. It does seem to have a positive effect on my metal state.
I don't know why but it seems to take my cravings away or at least lessen them. Almost as if breaking the cycle of processed food for a day reduces the addictive aspects. I'm much more inclined to cook a fresh health meal for tea than eat rubbish.
Now I don't particularly want the cakes people bring into the office, even on the feed days, whereas before I’d have one then be desperate for another. It would seem obvious that the weight loss is because of the lack of calories on fasting days but I suspect it also has a lot to do with the changes it makes to the feed days.
My friend did two non consecutive fasting days a week and she lost 2 stone this year. After trying to get down to a healthy BMI all her adult life (30 yrs) it really made a difference.
It sounds counter logical at 1st but really it is probably what we were designed to do before grain storage and refrigerators/freezers.
Weight loss is the thing that's made it popular but the health benefits seem more far reaching involving anti aging aspects. The horizon program that brought it to people’s attention claimed that it reduced the risk of cancer, off-set dementia, reduces cholesterol and controlled blood sugar levels. More human trials need to be done to back these claims up but you have to wait a few decades for that.
Obviously you would only want to do it on rest days but it seems a good idea for runner’s because the weight loss is all fat. A recent paper pointed out that conventional constant calorie restrictive diet weight loss is between 3-5% muscle.
I have done it before a knee operation derailed me a bit. I find it both easy and hard. It's very simple but it does take a bit of motivation at 1st. The big thing for me was how my overall attitude to food changed. Before I didn't ever feel that hungry but was always compelled to eat rubbish. Now I feel hungry but oddly not as compelled to eat, I can wait until a planned meal rather than raid the vending machine. I also think not eating between meals and avoiding processed food helps.