Weight Control
Our body has complex systems to regulate food intake according to the need. If we are active and burn much energy, our appetite increases and we eat more food to replace the calories burned. Conversely, if we are passive and burn less energy, our appetite decreases and we eat less food.
The regulation of appetite is very complex and involves many systems in the body including the nervous and hormonal systems.
Hunger signals
When the body needs food certain hunger-signaling peptides like neuropeptide Y (NPY), orexin, and ghrelin increase and this activates the mind and body to seek and collect food and start eating.
Satiety signals
About thirty minutes after the start of eating, satiety signaling peptides (including leptin, cholecystokinin, glucagon-like peptide 1 (GLP-1), and insulin) are liberated from the gastrointestinal tract, pancreas, liver, and adipose tissue. The satiety signals reach the nervous system, which then gets the body to relax and stop eating. Important: Because of the delay in satiety, it is essential to eat slowly and to include breaks in the meal.
Weight Control Problems
The Western populations have experienced increasing problems relating to weight control.
In some people, the intake of food is much larger than the body’s needs, and this leads to weight gain, overweight, and even obesity.
In other people, the food intake is less than needed, and this leads to weight loss, being underweight, and in some the serious condition of anorexia nervosa.
How to assess your weight status and caloric needs
Body Mass Index (BMI)
You can obtain a measure of your weight status by calculating the Body Mass Index (BMI), which relates the body weight to the height using this formula:
BMI = weight in kg / (height in meter x height in meter).
Here is a link to a page, where you can calculate BMI easily using English or metric measures.
Optimally your BMI should be between 18.5 and 25. A BMI below 18.5 indicates being underweight. BMI in the interval 25–29.9 indicates overweight. A BMI of 30 or higher indicates obesity.
Caloric requirements
Your caloric requirements depend on your age, your body dimensions, and your activity level. Younger people need more calories than older people. If you are physically active, you need more calories than if you are resting. Here is a link to a page, where you can calculate your caloric requirements. Follow the directions on that page to make a correct calculation.
If you need to lose weight, you should eat less than your caloric requirements. If you need to gain weight, you should eat more than your caloric requirements.
How to lose weight
In the modern world, many find it difficult to maintain a healthy weight. An important factor is the abundance and easy availability of food. For this reason, we eat too often and too much.
Numerous diets have been devised, some of which may have a slight, temporary effect.
An important point is to limit the intake of carbohydrates, that are not essential nutrients. Excess carbohydrates will be transformed into fat and stored as such in the body.
Sufficient protein is important. The Ducan diet is based on high protein content in the food.
However, the most effective way of losing weight is to reduce the number of calories eaten by including a form of fasting on certain days. Popular examples are the Every-Other-Day Diet, the 5:2 diet, and the FastDiet.
What is realistic weight loss?
Over the long term, it’s a good idea to aim for losing 0.5 to 1 kilogram (1 to 2 pounds) a week. Generally, to lose that much, you need to burn 500 to 1,000 calories more than you consume each day, through a lower-calorie diet and regular physical activity.
You may accelerate the weight loss by exercising and thereby burn more calories as shown in the video below. However, you should remember that exercise can only be a supplement. And remember: exercising increases your appetite. The only effective way of losing weight is to eat less.