Hi:
I am seeing much more confusion between doing 5:2 and ‘fasting’. Another way to put it is confusion between severe calorie restriction and the length of time between eating. For the record, it is the severe calorie restriction twice a week that leads to weight loss when following 5:2 (and, perhaps, other ‘health benefits’), not the time between eating.
5:2 was born from a documentary Dr. M did on calorie restriction and life extension (not weight loss). Only one of the four basic segments of the show was on fasting. That segment was all about a four day fast that yielded good blood work results (‘fast’ meaning eating no food for four days) . However, the researcher involved said that to continue benefiting, you would have to do four day fasts monthly (I’m going from memory), and Dr. M decided that he could not do fasts that often even if he did get the positive results.
Another segment was on a man that had been eating 1900 calories a day for over 10 years. He weighed 134 pounds and was in excellent health. Dr. M decided he could not do that, either. A third segment was on ADF – alternate day fasting – where people alternated between eating 500/600 calories one day and eating what they wanted the next. That approach yielded good blood work and weight loss results regardless of what people ate on their non diet days. The fourth was on calorie restriction and Alzheimer’s. Initial research on animals indicates severe calorie restriction can delay its onset
At the end of the show, in consultation with the researchers, Dr. M came up with what we now know as 5:2 and decided to try it for five weeks. It worked for him, yielding good blood work results. The show noted as an aside that Dr. M lost weight. After it was aired, people tried 5:2 (presumably for the potential health benefits) and began losing weight. Recognizing a good thing when it appeared, Dr. M quickly wrote a weight loss diet book (not a life extension diet book), and the rest is history.
The point is 5:2 is about calorie restriction, not fasting in the sense of time between meals. To explain, I see people not eating (fasting) for 24 hours (say, 2 pm to 2 pm the next day) and thinking they will automatically lose weight. But they eat their TDEE before 2 pm (because they will not be eating for a ‘day’) and eat their TDEE after 2 pm the following day (because they are hungry), often with 500/600 calories in between. There is no calorie restriction, they do not lose weight, and they quit because ‘it does not work’. It is the same for 16:8, don’t eat until 5 pm or any other ‘time between eating’ diet plan. They can work, but only if you count your calories and make sure you eat under your TDEE every day. They are reduced calorie diets, that do not have the potential health benefits that come from severe calorie restriction, using an IF (‘Intermittent Fasting’) label. I have nothing against any weight loss diet ‘that works for you’, but this is the 5:2 site, so I am focusing here on how ‘the real 5:2’ works (not options or off-shoots).
So if you are a newbie here because you want to try 5:2, I recommend you start by doing 5:2 correctly for at least two months before you start thinking of doing something else.
‘Doing 5:2 correctly’ means going to bed, getting up, eating 500/600 calories while you are awake, going to bed, getting up and eating normally – twice a week. ‘Normally’ means eating your TDEE or less. Here is what you need to know about TDEE: http://thefastdiet.co.uk/forums/topic/tdee-for-the-curious-or-why-dont-i-lose-weight-faster/. And here are some general tips for those just starting: http://thefastdiet.co.uk/forums/topic/warnings-to-newbies/.
There are tens of thousands of people quietly being successful with 5:2. The ones who are not being successful generally are simply eating too much on their non-diet days (and often their diet days, too). It makes no difference if you eat a (small) breakfast, lunch and/or dinner on your diet days, eat only one meal or don’t eat anything, because time between meals is irrelevant. It is the severe calorie restriction twice a week that counts!
Good Luck!
5:34 pm
19 May 14