Hamburg - Finally, you've lost the 15 kilograms you had hoped to lose, your body has emerged healthy and more agile and that dress that gathers at the waist fits you again.

After dieting goals such as these have been achieved, it's easy to start thinking that a piece of cake here, a chocolate bar there, or a little glass of sparkling wine in the evening - exactly the things forbidden during the successful diet - can't be so bad.

But, beware: the faster old habits return, the quicker the pounds pile on again. People who want to avoid yo-yoing, characterized by repeated weight loss followed by weight gain, have to be prepared to completely change the way they eat and commit themselves for life to a new way of eating.

"The alpha-to-omega of successful weight maintenance is continuing physical activity and eating a balanced diet," said Gudrun Prinz, a nutrition consultant with Germany's main public health insurer. The important thing is after dieting for a while is to continue eating several small meals a day as most diets advise.

"Weigh yourself regularly and eat only when you feel hungry," said Prinz. She added that people, who want to maintain their weight, should apply the eating and exercising habits they learned while they were dieting to their lives.

Margret Morlo, a spokeswoman for a German association for nutrition and dietetics, said the way women are portrayed in the media makes women's bodies and their weight an important topic.

"In the media women who are thin, shapely and exceedingly pretty are presented as representative of the 'normal' population," said Morlo. Many women would like to conform to this ideal, and therefore pay particular attention to their bodies.

"In a smaller portion of the female population, a health aspect possibly is brought to bear because sporty and slim women live healthier lives than overweight or even obese women."

People who have successfully lost weight, but cannot maintain the weight loss should research the cause and understand why it happens. Many women eat because they are frustrated over how little time they have for themselves. For others, the root problems is they don't have enough to do.

"One of the tactics I suggest is that women who eat out of boredom take up a hobby or challenge," said Morlo. "Then whatever is triggering the eating disappears and so does the excess weight."

It's important that women who take care of their families do not forget to allow themselves enough rest and free time.

"A person's environment can ease or impede a change in eating," said Lucia Pferdekamp, spokeswoman for a German association of independent health consultants. "It's helpful when the partner is supportive and even better when he encourages exercise."

If a woman finds that her partner is not supportive, she should seek allies, such as a girlfriend or the members of a fitness or nutrition group. But even when the family is supportive, setbacks in weight loss cannot be ruled out. And typically pounds tumble off slower than one hopes.

"Often the weight-reduction goal is set too high and resistance against the goal - one's own as well as resistance in the environment - is not well recognized and not taken into account," said Pferdekamp. The result is the person trying to lose weight is frustrated and motivation sinks. In this case it's best to keep a cool head.

"Setbacks are normal. No one should take the blame for that and a fear of failure should not be established," said Pferdekamp. It's better to accept the situation, reconsider the goal, believe in oneself and continue working on the necessary changes.

People who are dieting are often reluctant to reveal it because they fear failure or feel ashamed. The reasons are many, however, women should confide their goals to colleagues and relatives.

"You should communicate openly with the people around you, making it clear that you're goal is to lose weight and that you've changed the way you eat," said Prinz. Then it's easier for colleagues to understand why at an office party you turn down cake and alcohol.

"You can't change your environment, but you can give it a clear signal that you haven't changed your personality and you are not sick or crazy, you are just trying to lose weight and that's doing you good."