Is very common for people who yo-yo diet, where they are constantly taking off weigth and putting it back on again, in an endless emotional roller coaster to end up weighing more than if they had never dieted in the first place.
The reason for this is the body begins to change in an effort to maintain energy levels and by doing so stores more fat.
This also causes the body to use less energy for all activities even when exercising and as a result it becomes more and more difficult to lose weigth and even when you go on a similar diet to one you might have previously achieved some weigth loss from it is likely that you won't be able to lose the same amount of weigth the next time around.
People who are constantly on yo-yo diets cause their metabolism to change to an extent where they require a bigger reduction in their calories than a normal person would to maintain their new weigth due to the body's new and reduced demand on energy.
This is linked to our evolution where food would often be scarce and the body adjusts accordingly to conserve and maintain its fat reserves when there is a shortage of food.
The downside of this happening is that after people go off these particular diets they tend to put on more weigth than they were before they started and in doing so it becomes all the more difficult the next time to try and lose their additional weigth so if you are the type of person who can't stick to a particular program for any length of time then you are better not starting at all and just making small steps by reducing portions of food will have better results long-term and will be a lot easier to maintain.
