After the holidays and after many comfortable winter evenings, many people notice they have put on weight, particularly on their hips, thighs and buttocks.
But one or two kg of additional weight should not cause panic, said Isabelle Keller of the German Society for Nutrition in Bonn.
"When people return to their usual nutritional habits and become more active, the kilos go away quickly," Keller said. However, there is a problem when people put on weight over the holidays year to year and never lose it.
Pills and laxatives are just as ill advised as crash diets. The pounds tumble off, but they return quickly once the diet is discontinued. A better approach is to recognise what is causing the weight gain.
It usually is overeating or eating a poor combination of foods. The only certain way a person can lose weight, keep their weight steady and remain healthy is to change to a balanced mixture of healthy foods and to get enough exercise.
A weight loss programme can be a good start. Germany's consumer testing organisation found one-third of 90 programmes tested to be recommendable or worth a try. All good diet programmes include a lot of vegetables, fruit, wholegrain, not more than 30 grams of fat in a day and little or no sugar.
"Eating meat three or four times a week is enough. Calcium in the form of milk should not be left out," said Dorothee Lennert of the Berlin-based organisation. It's important that a diet fit the person's needs, Keller added. Complicated calorie calculations before every meal is not practical, and when cooking all ingredients must be easily obtainable.
In addition a good time to start should be set. An especially stressful period or the beginning of a vacation are not good times to start, said Andrea Benecke, psychotherapist at the University of Mainz.
"And in light of the hormonal changes the body goes through during puberty and menopause, it is difficult to reach a weight loss goal during those times," she said. Dieting while pregnant or nursing should never be undertaken.
Lennert recommends people tell their family and friends loudly and clearly: "In future, I'm going to eat differently and cook differently. "Then it is up to them to stick to it. A good change of habit is to go shopping with a list and not to fill the shopping card with extras that aren't part of the plan.
"Drink something before or during the meal or eat a salad so that the stomach is active," Benecke suggests. Watching television while eating is a distraction that often leads people to devour more than necessary. Also, when pots of steaming food remain on the table, people tend to reach for more. It's not as easy to do that if the food remains in the kitchen.
An initial drop in weight that is noticeable on the scale is important for motivation. But the goal must be realistic and sensible.
"A big danger is losing too much weight too fast," Lennert warned. "Then the metabolism changes and uses the calories available more readily."
A weight loss of about two kg per month is completely sufficient.