How come so many supposedly genetically-gifted people seem to be piling on the weight and letting themselves go? Personal Trainers, and founders-owners of The DoubleVision Conditioning Centre, Stephen and Mark Gray, have compiled the three most likely reasons.

Take on board what they say to avoid the same fate!

1. Following very strict starvation diets: these make you lose muscle (hence the gaunt look of a lot of these stars), increase your appetite and cravings which result in an increased chance of rebound weight as you ultimately can't survive long-term on so few calories.

2. Setting unrealistic deadlines: leaving themselves very little time to get into red-carpet shape means that crash diets are the only answer for the likes of Britney. This means she has to diet so hard that a balanced life goes out of the window and, sooner or later, she ends up bingeing on food and alcohol.

3. Missing meals: by missing meals celebs may lose weight in the short term, but not only does this cause moodiness (anyone ever heard of someone famous hitting a photographer?) but it also lowers metabolism so that when they do start eating they are more likely to put on fat.

Visit www.doublevisionpt.com and begin meeting your fitness goals today!