5:2 Diet Experiment

I started to hear about the 5:2 diet and other variants toward the end of 2012. A Horizon program explored the subject of intermittent fasting (IF), which I heard about by word of mouth. The program is no longer available on iPlayer so I’ve yet to see it.

Disclaimer: This is not dietary advice. Speak to a doctor before trying crazy diets you read about on the internet.

Anyway, I approach this from a strange position. I’ve never dieted before, and I’ve always been able to eat whatever junk I want without any fear of putting on weight. Assuming I was just one of the lucky ones, I just ate anything I fancied.

Then I hit my mid-twenties and things started to change. I didn’t suddenly pile on the pounds but sure enough, as every year passed I was getting slightly heavier. Maybe this was natural, maybe my sloppy eating habits were catching up on me. I don’t know. All I know is that I decided to do something about it. I didn’t fancy ignoring it into my forties and then struggling to shift a huge load of weight.

Enter the 5:2 Diet

In its simplest form, the 5:2 diet involves two fasting days and 5 normal (non-fasting) days. I chose Monday and Wednesday as fast days as they fit in well with work. I think you’re meant to leave a gap of at least a day between fasts to recover.

On fasting days I get a measly 600 calories to keep me going (500 for girls). I’m sure there are a million different ways of arranging that but I can’t skip a meal without feeling ill so I arrange my fast day like so:

Breakfast – Banana. (100 Cals)
Lunch – Soup. (Cuppa soup is fine and helps keep the portion small. (100 cals))
Dinner – Small meal of Rice, Chicken, and Veg or something similar. (400 cals)

Now that sounds like a savage diet and I would guess that if you ate like that every day you wouldn’t last very long. The best thing for me is that however hard this diet seems on fasting days, you can eat a normal amount of food on the other days. This suits me fine. It means I can still go out and eat, still have takeaways & chocolate (in moderation of course), and still lose some weight.


Many religions involve some sort of fasting, so this is nothing new. Even going back to hunter-gatherer days, if you didn’t catch an animal then you’d have to make do with some low calorie roots, berries or plants for dinner.

Side Effects

There are apparently some interesting (but not bad) side effects to this type of diet. Reduced cholesterol and other dangerous markers are the main benefit aside from the actual weight loss.

I found that on the day after a fast, I usually get extra hungry about an hour before lunch, but would not actually eat any more than usual. Overall I find that I seem to eat slightly less on the day after a fast than I usually would. On normal (non-fasting) days I don’t count calories at all.


After a four week trial of the 5:2 diet I lost half a stone (~3 Kilos / 7 Pounds). That doesn’t seem dangerously fast to me, and I don’t feel like I suffered any ill effects from doing so.

I hope there is some proper research published about this type of diet, as it actually sounds too good to be true. It sounds exactly like the kind of trash you get in glossy magazines, but so far my experiment has proven to me that it works.