I personally always ate more on non-fast days than I normally would have if I hadn’t been fasting at all but I usually didn’t eat so much that I didn’t lose weight anyway. Now I’m trying to maintain my weight while still fasting two days a week and I think I’ll be able to do that too, but I’ve bumped up my fast day calories to 500 from about 300 most of the time when I was trying to lose weight. I might still be losing weight, not really sure yet.

If you can keep down to normal calories on non-fast days, then you should be able to lose a couple pounds a week on average. If you’re like me (and most people, I imagine) and you eat more and don’t really try to diet, then you lose less. I think if I started going big into butter, cream, cheesecake etc. might gain weight even with 2 fasting days, but I don’t do that so I don’t know for sure. But lots of people report not losing weight and one obvious possible problem for them is overeating on non-fast days, so I recommend avoiding high cal foods on non-fast days, especially when you start so you can be sure to get some weight lost.

There is also the potential issue of lowering your base metabolic rate if you restrict you calories to below TDEE all of the time for a few months. But if you were actually doing this, you’d be losing too much weight (more than two pounds a week for an average size person). One possible advantage of intermittent fasting is that you can avoid this by eating to TDEE on non-fast days most of the time and still lose weight.

Ultimately though, to avoid the yoyo, you have to put together a plan you can live with forever. And for me that means not counting on non-fast days, not giving up cheese, cream, butter etc, or anything else in moderation but I’m ok with the two fast days forever. Some people eat less and go to 1 fast day.

Hi Fitbug:

The way 5:2 works is you go to bed, get up, eat 500 or fewer calories during your waking hours, go to bed, get up and eat to your TDEE or less – twice a week. On all 7 days of the week you can eat foods you want to eat – there are no forbidden foods, or foods you have to eat. For the first month or so focus on doing your diet days correctly (500 calories or less) and most everything else will fall into place.

Here is what TDEE means: http://thefastdiet.co.uk/forums/topic/tdee-for-the-curious-or-why-dont-i-lose-weight-faster/

And here are some tips for beginners: http://thefastdiet.co.uk/forums/topic/warnings-to-newbies/

The key is for the first month or so, focus on doing your two diet days correctly each week. You already realize you can’t overeat on your non diet days, but don’t get too worried until you have done 8 to 12 consecutive diet days correctly. Give 5:2 a chance to get going. Then you can focus on your non diet day menus.

Good Luck!

Fitbugslim, I found that after a few weeks my appetite and the amount I could eat on non-fast days changed. I could not eat the same amount of muesli for breakfast and then slowly changed to more protein/vegetable and less starch based food.

But I know where you are coming from with the good and bad foods, most of us here will have been told that we cannot have certain things because we are fat and want to lose weight. That is how calorie counting works but 5:2 is different. Nothing is totally forbidden, and in my case the moderation arrived in time all by itself.