Intermittent fasting, The Fast Diet, The 5:2 Diet

Posted on May 9th, 2015

This post is inspired by my many patients who have absolutely transformed their health by practicing intermittent fasting.

In over 20 years of practicing medicine I have never recommended that my patients undertake dieting for the simple reason that fad diets do not work in the long-term. People might lose some weight initially but as soon as they stop the diet the weight eventually comes back on. I hesitate to call intermittent fasting a “diet” for this reason; and really it should be thought of as a healthy way to live rather than as a diet.

Intermittent Fasting (IF) has been practiced for centuries by various groups of people and is a core practice of many religions. More recently scientists have shown that IF is likely to have health benefits that include a lower risk of diabetes, a lower risk of heart attack and stroke, a lower risk of cancer and a lower risk of dementia. These benefits have yet to be absolutely proven by science but there are currently studies going on in all these areas.

Intermittent Fasting as a workable lifestyle modification was developed by Dr Michael Mosley and Mimi Spencer and called the “5:2 Diet” or the “Fast Diet”. If you are interested the book has much more information than this brief introduction.

IF is very simple:

There are 7 days in a week

It works best if you do not fast on 2 consecutive days. Most people fast on week days e.g. Mon & Wed or Tues & Thurs, however there are no absolute rules about this.

The fasting days are flexible e.g. if your fasting day is usually a Wed and you are invited to dinner with friends you can switch your fasting day to a different day.

If you undertake this method correctly it will work. To do it properly you must accurately calculate all the food and drink you consume on your fasting days. This requires 2 things: a set of digital kitchen scales (you can purchase these online for as little as $35) and a Calorie Counting Reference. If you have a smart phone there are many Calorie counting Apps that are free (e.g. MyFitnessPal, FitBit etc.). If you are not so technically inclined there is a detailed Calorie counting reference at the back of Dr Michael Mosley’s book (which you can buy for as little as $14)


Food Weight Calories
Cucumber, Lebanese 100g 12
Carrot 100g 42
Capsicum, red 100g 25
Baby Spinach 100g 23
White wine vinegar 15ml (1tbsp) 3
TOTAL   103 Cal

Add to your salad Australian Lamb backstrap 100g = 130Cal Total = 233Cal