The FastDay Forum

Hi All:

There must be some newbies out there interested in how 5:2 and other diets work 'by the numbers'. Losing weight fast is really not an option over time if you want to eat anything along the way.

Good Luck!

Every once in awhile, someone does wonder about how weight loss occurs 'by the numbers'. Maybe this will help.

I've played around with TDEE a bit, and get all sorts of different numbers, depending on what calculator I use. Going by the one posted in the OP, it gives me a number of 1,900 with 'active' as active level (I do 3 days/30 minutes strength training and 2 days/20 minutes jogging/jump roping on rebounder). Since I'm experimenting with IF and maintenance right now, if I do the math for 6:1 it looks like 1 day would be 500 calories and then the other 6 days would be 2,133 calories a piece. Versus Varady's maintenance plan, which would give me 3 days of 1,000 calories a piece and then 4 days of 2,575 calories a piece. Interesting to see how the two are laid out, when factoring in TDEE I like the idea of 6:1 because I'd just have to deal with one day out of the ordinary per week. However, that leaves more room open to mishap, with 6 days at higher calories. Varady's plan sounds a bit better, but I don't know how I'd be able to eat that many calories on my 4 normal days-I foresee continued weight loss with this method and since my bmi is already around 19, I don't have a lot of wiggle room for more weight loss.

Will have to experiment with them and TDEE, and see which one is a better fit!

Feeling a tad fed up today, this is my 2nd week of fasting and yesterday was my 3rd fast day.
I know it's early days and I shouldn't weigh myself after a week, but I had hoped I would have at least weighed the same, but I am 4 pounds heavier
Is this normal? I have over 3 stone to lose.

Could be lots of reasons - what are you eating on your non fast days? Have you worked out your TDEE because I know some places it says a blanket 2000 cals for women on non fast days but that would never have made me lose weight even at my heaviest. There is loads of useful info on this site and a TDEE calculator (so you know what you should be eating on non fast days). Contrary to what they say in the media - 5 2 isn't '2 days of fasting and 'eat all you like' during the rest of the week!! Have a read on here - there's lots of great advice. But don't give up! It's not the fastest weight loss in the world but it is sustainable and it works.

Probably water retention.

I have been on the 5:2 diet for 18 months and after losing 9kgs I have come to a halt. Is this to be expected?

Welcome @mike&jean. Well done on your loss! Yes it is very normal to have a plateau. Lots of conversation threads about these here. Sometimes you just have to sit it out. Can you tell us more about your current BMI and maybe what you are eating?

I think three things are likely to happen as you lose weight. First, as your weight goes down, your TDEE goes down. You're carrying less weight around so you burn fewer calories than you did before. Thus, if you are consuming the same number of calories as when you first started losing weight, your calorie deficit is smaller, or non-existent. The second is that you might actually be consuming more calories than when you first started--you're not as careful, you're getting "fasting fatigue", etc. Finally, when you've been dieting for awhile, your TDEE is actually lower than predicted. This could also cause you to have a lower calorie deficit or to end up in surplus. (By you, I mean in general, of course)