• It must be introduced slowly.

• It must not be too severe in the degree of restriction or the weight loss that accompanies it (see below).

  Note: Weight loss is not the aim of Calorie Restriction, but is a usual by-product of it.

• It must incorporate FULL nutritional content of ALL nutrients except calories.

• Calorie restriction for children is completely contraindicated and ideally no-one under the age of 20 should attempt these methods.

• It is never too late to start, but the older you are when you start the slower must be the introduction of calorie Restriction.

• Calorie restriction methods are inappropriate for diabetics, people with eating disorders or chronic disease, or who are suffering mental disease requiring regular medication, unless supervised by a suitably qualified adviser.

The most important aspect of calorie restriction methods is that the diet must contain an optimum level of ALL the nutrients required for good health, within a calorie intake which is tailored to the individuals particular needs, bodyweight etc.

Walford and Weindruch¹⁵ give guidelines for successful application of these methods to humans.

• First it is necessary to find your 'set point'. This represents the weight you were (or are) between ages 20 and 30 whether your weight has remained stable since then or not.

• Based on this set point you must ensure that as you adopt calorie restriction methods (full nutrition with calorie restriction) which does not allow your weight to fall more than 25% from that set point weight, or less than 10% below it, in the first year.

• An intake of between 1800 and 2000 Calories per day will satisfy the requirements of Calorie Restriction for most people.

• One well formulated multimineral and multivitamin supplement is suggested daily to ensure no that deficiency is triggered by the programme.

• The programme should be started slowly (especially important in the elderly) and weight loss should not be rapid.

• The selection of foods is based on what are called Exchange Units.

Exchange Units
This is a method commonly used by Diabetics, in which each category of food (Fat, Grain/starch, High Protein, Fruit, Vegetable and Dairy) is assigned a fixed unit of measurement (cupful, tablespoonful etc) which represents a particular number of calories (and in the case of fats and proteins a set number of grams of each of these).

Exchange Units give you the chance to select foods according to personal taste while staying within a framework which guarantees balance and full supply of essential nutrients.¹⁶

Lists are provided which tell you how many Exchange Units each measure of a particular food group carries, and whether it contains protein or fat and if so how many grams of each.

You are also told how many Exchange units of each category, and how many grams of protein and fat you need (based on your current bodyweight) to consume daily in order to ensure good health.¹⁷

Using these guidelines you construct your own choice of foods making sure of the required number of Exchange Units, grams of protein and fat, and in so doing the calorie intake will take care of itself. You do not need to count calories!¹⁸

Other Methods?
A long list of life extension methods have been promoted over the years.