Welcome here Phoxy,

Basic 5:2 is to have a maximum of 500 calories on your two ‘fast’ days a week, if you are a woman, and 600 calories if you are a man.

However, if you feel that this would be unsustainable, or if you try it and find that it is unsustainable, then Dr Mosley suggests raising the maximum limit to 800 calories on your two fast days. This will still work for your health and for weight loss.

You could also start by doing 800 calories on your fast days and later on see if you can cut the maximum calories down a bit.

Make it ‘do-able’ and a sustainable part of life and you will be doing it right!

Good luck.

Hi Phoxy
Weight loss is slower on 800 calories fasting but I managed to drop 30 pounds in 10 months doing 2 x 800 calories a week and have continued doing that since May to maintain my new goal weight. I struggled to do 500 calories days as I was too hungry on non fasting days so was eating too much on ‘slow’ days…..this doesn’t happen when my ‘diet’ days are at 800 so it works better for me. Everyone is different so finding your own way with 5:2 takes a little trial and error. Experiment and see what suits you best. Good luck and enjoy!