The Science Behind Obesity 

Obesity is a complex chronic disease influenced by many factors both inside (biological) and outside (environmental) the body. 


By Mads Tang-Christensen, Corporate Vice President Obesity Research |  3 min read

Food is our main source of energy. The energy we need to live our lives every day comes from the food we eat. Our body weight increases when our energy (food) intake is not equal to the amount of energy we use. This is referred to as our "energy balance", and is influenced by factors or how they interact both the inside and outside of the body. 


Inside the body: biological factors 

Your genes play a big role in determining your physical traits. Just like you can inherit genes that give you blue eyes or curly hair you can also inherit genes that predispose you to developing obesity.  Obesity associated genes have been linked to energy balance, fat storage and appetite.

Our appetite or desire for food helps us to help regulate our food intake and maintain a healthy weight. 

Specialist cells in the stomach and the gut play an important role in regulating our appetite as do hormones. For example, when we are full hormones in the stomach and the gut send a signal to the brain telling it that we have eaten enough.


However if something goes wrong with our appetite then this can lead to us not eating enough (malnutrition) or eating too much (overweight and obesity) both of which can cause serious health difficulties.

Our emotional wellbeing can also influence our appetite. For example stress, tiredness or emotional upset can sometimes lead us to eat more. Getting enough sleep is also very important in helping us maintain a healthy weight as studies have shown that a lack of sleep can make us feel hungry and eat more. 


Outside the body: environmental factors

Where you live and how you live can both have an impact on whether or not you develop obesity.

We all know how important regular exercise for a healthy life. Activity is the body’s way of burning off excess energy that we have consumed. If we don’t’ burn off the excess energy, our bodies store it as fat. Therefore it is important to take regular activity to prevent weight gain. 

A number of aspects of modern life have also had a significant impact on our ability to maintain a healthy weight. These include the increased availability of cheap unhealthy foods that are high in fat and sugary drinks. 


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