Hi jonathan. Your post interested me so I had a look at it. I have no scientific knowledge or background but I have some comments to make.There seems to be a bit of confusion re energy intake in the report. Mice were used, naturally. Quote “1st ten days were put on an energy rich diet followed by 4 days of restricted energy intake. This cycle was repeated 4 times in the course of the experiment”. A control group was fed the same energy rich diet without fasting.
Quote “Surprisingly at the end of the experiment the total energy intake was aprox the same in both groups”. The mice that fasted….. had almost twice as much fat in their liver…….The intermittent fasting group also had more visceral fat…..
According to this research report it reads to me that the mice that fasted still had almost the same energy (fat) intake as those mice not fasting.
The experiment took place over aprox 56 days ie 10 days + 4 days (14) by 4. (My estimation.)
If the fasting mice had the same energy intake as non fasting mice over a shorter feeding time period then it is possible that this may affect fat storage in liver.
Now, if you have the original “The Fast Diet” book, page 43, Michael comments on similar research carried out by the Salk Institute for Biological Studies. The experiment lasted 100 days. Again mice were used. One group were forced to fast over 16 hrs per day. At the end these mice, despite having eaten exactly the same amount of food suffered much less liver damage and put on far less weight (28% less)……
So two different results from different experiments.
The Scientist in the Nordic experiment described the 5:2 diet as “A fad diet”. If you follow the links in the report you will see other research showing that the new “Nordic Diet” is the healthiest yet this “New” diet of healthy “Nordic” food uses food groups found all over the world. This new diet is not described as “A fad diet” Could there be some ulterior motive at work here?.”
Crucially in both experiments a high fat diet was the norm. We humans, when fasting do not, I believe stick to a high fat diet. In addition much other research into fasting and diet shows that “Fasting” generally has positive health benefits. Fasting has been around for thousands of years. Michael who made himself a guinea pig showed that his tests prior to his fasting were a worry but that after they showed positive improvements.
Finally remember there a two other main researchers in the book that Michael refers to. Krista Varady and Valter Longo, both experts in the field of Fasting research. Oh and I nearly forgot… all the posters following the 5:2 who report positive weight loss and other health benefits.
Good luck to you all out there.

Hi Jonathan,

Can I ask how you went with the tests in regard to fatty liver? I’m really enjoying 5:2 when I can stick to it, but wonder about long term effects to?