After your fortieth is harder to keep your figure slim and weight continue for a number of factors that change in your body. It may cost a bit more effort, but it is not impossible.
Changes
After the fortieth you will change some things in your body. Your cells regenerate more slowly, your muscle mass decreases, your hormonal changes. It takes more effort to keep the same weight and not to come. And if a gain weight, you need more effort to lose them again.
Slower metabolism
Your body needs energy to function, even if your body is at rest. Your basal metabolic rate (BMR) is the number of calories you burn when your body is at rest. This BMR is different for everyone depending on your gender, weight, height, etc. After your fortieth, your basal metabolic rate is lower. To be precise, take your metabolism after your fortieth every 10 years by 5%. To give an example: You are a woman of 40 and your BMR is 1400 calories.
Other Food
The solution is here and it is very simple. The number of calories you burn must exceed the number of calories you eat through your diet. But you must now get fewer calories for the same weight. That does not mean you should eat less, you can also choose to eat differently. Deepen your example in the Mediterranean diet. Replace unhealthy fats with healthy fats and carbohydrates by fast slow carbohydrates.
Do not even think about the diet
To follow a diet to lose some extra weight is definitely not the best option. Changing your life require changing in your lifestyle is. Make sure you use that many calories and good nutrients let empty calories such as sweets, cakes and snacks as many left.
More exercise
Another need is more exercise, and not just because it burns calories you. After you reach your fortieth; your muscle mass decreases. And if you, like most especially a sedentary, your muscles will disappear quickly. And the more muscle you have, the higher your basal metabolic rate (BMR). You lose muscle mass then your BMR even lower, unless you put them to work. A combination of cardio and some strength training is working the best.
Good balance
It is not just about looking good to keep seeing. A healthy weight contributes to your health. Try a good balance between healthy diet and exercise, then you succeed sure to maintain your weight, even after you are forty.