How can I find my ideal weight?

The World Health Organization (WHO) defines weight categories according to the Body Mass Index (BMI).

To calculate BMI, divide your body weight (in kg) by the square of your height (in m). An example: the BMI of a person with a height of 1.75 m and a weight of 70 kg is 22.86 kg/m².

The following values apply for adults over 20 years of age:

• Underweight: under 18.5 kg/m²
• Normal weight: 18.5 to 24.9 kg/m²
• Overweight: 25 to 29.9 kg/m²
• Obesity: 30 kg/m² or more

From a medical perspective, just looking at a person’s BMI, weight or waist circumference does not allow you to form an opinion about their health. In most cases, weight is not the cause, but rather a symptom of an unhealthy lifestyle or a physical problem. You can find further information on this topic below.

The terms normal and ideal weight are often used interchangeably. However, they do not mean the same thing. Normal weight is calculated using the BMI. Depending on your height, there is a weight range that is deemed “normal”. Conversely, ideal weight is personal. It depends on a person’s goals and what aesthetic appearance they are aiming for.

However, weight is not only associated with health and physical well-being in our society. It strongly influences our lives – from our career to our choice of partner. As a result of this social pressure, even healthy people with a normal weight often wish for a slimmer figure. On the other hand, there are also people who are comfortable with being overweight, and thus consider this weight to be the ideal weight.

David Fäh, doctor and nutritionist, says: “There is no simple answer to the question of what an ideal body looks like. I realise this time and again when I see athletes: while shot-putters are mostly severely overweight, marathon runners are often on the verge of being underweight. However, both are probably healthy. Radical diets make little sense to achieve your ideal weight. Often you lose sugar reserves, water or muscle mass and not the desired fat – those lost kilos are quickly regained. It is much more sensible and easier to maintain your own body weight. If you take care not to gain weight as you get older, you will come closer to your desired weight in the long run.”

Weight fluctuations of up to three kilos within a short period of time are normally no cause for concern. Possible reasons for this are changes in the body's water balance or carbohydrate stores. For example during intensive exercise, the body can lose between 1–2 kg. But if our digestive tract is full, this can also affect the number on the scales.

However, you should seek medical advice if you unexpectedly lose or gain weight without explanation within a few months. Because such weight fluctuations can indicate diseases:

• An overactive thyroid gland increases calorie consumption, while an underactive thyroid gland slows down metabolism.
• Gastrointestinal diseases and infections in the body can impact hunger.
• In the case of diabetes, the body no longer absorbs glucose. Therefore, it draws on fat reserves and the person quickly loses weight.
• Some types of cancer can affect hormone balance and weight – as can heart and lung diseases or side effects of some medications.
• Stress causes the body to produce more cortisol. This significantly affects eating behaviour and metabolism. Therefore, a change in weight can also have a psychological cause.

The number on the scale does not only depend on what we eat and how often we exercise. There are many other factors:

• Age
  As we age, our metabolism slows down and our basal metabolic rate decreases.

• Personality
  Neurotic, risk-taking, sociable or impulsive people in particular experience major weight fluctuations.

• Hormones
  Regulate hunger, appetite and energy balance among other things.

• Genetics
  Genetic variations influence energy balance and the regulation of hunger and satiety.
• Sleep
  A lack of sleep affects hormones. As a result, it alters the metabolism and the regulation of hunger and satiety.

• Socio-economics
  The lower the social status, the greater the risk of obesity. That said, education clearly influences weight more than income or occupational class.

• Stress
  Stress hypophagics lose their appetite, while stress hyperphagics – also called stress eaters – feel an increased desire for sugar and carbohydrates.

People who are within the range of normal weight according to the BMI have a lower risk of diseases related to body weight. On the other hand, being severely over- or underweight can have serious consequences on health.

Physical consequences of being overweight:

• Diabetes
• Heart problems and arteriosclerosis
• Bone and joint problems
• Breathing problems
• Some types of cancer

Physical consequences of being underweight:

• Osteoporosis
• Infertility
• Muscle atrophy
• Impaired wound healing
• Organ damage