Ronny Terry is a Swindon-based personal trainer. He has previously worked as Performance Analyst with Swindon Town FC and on obesity initiatives with the NHS. Tweet your questions to @SWITCHFITUK or visit www.switchfituk.co.uk

What is a healthy amount of weight to lose in a week? I have seen 1-2lbs quoted often, yet outrageous claims of a stone or more. I’d like to lose some weight but in a healthy way.

Weight loss really should be renamed ‘fat loss’. Fat is really what people are attempting to lose when starting a diet.

To some it may be surprising that the total loss may include other body mass such as muscle tissue, water and stored glycogen. Therefore a reduction in weight does not necessarily mean it is all from fat.

In order to lose weight a caloric deficit must be created and it is the size of this that will initially determine the rate of loss. Exercise can play a part in creating this deficit, but all the running in the world will make little difference if you are consuming more energy than you burn.

But with too large a deficit and poor nutrition, there is greater risk for losing body mass that is NOT fat.

Take in too few calories and your body may utilize muscle tissue for energy. It will also deplete stored glycogen (sugar) which carries with it a significant quantity of water.

Larger deficits may also have a negative impact on hormonal balance, which can be counterproductive. If your body senses inadequate quality and volume of nutrition, it will eventually slow down.

You may become sluggish, tired, hungry, burn less fat for fuel, and store more fat in an attempt to conserve energy.

For most individuals, 2lbs (or 1% of body-weight) would seem a reasonable pace for fat loss while maintaining body composition. That does not mean it is not possible to safely lose more with a well-balanced nutritional strategy, especially if you are working towards a time orientated goal. Everyone is different and starting weight, method, sex, age, levels of activity, support network and will power are all determining factors that should not be ignored.

Large, rapid weight loss usually comprises of significant amounts of body mass other than fat and is not sustainable or healthy for the majority people.

Consult your GP if you are planning on losing weight and have any concerns.

For more information about Ronny, visit his website at www.switchfituk.co.uk.