Is your brain chemistry responsible for your weight gain?

Is your brain chemistry responsible for your weight gain?

“Obesity” is a term frequently heard on the news and seen in our population, but what does it really mean to be obese? The World Health Organisation (WHO) classify Obesity as “An excess of body fat leading to negative consequences on health” (1997).

Clinically speaking, obesity is measured by Body mass index (BMI). Body mass index considers weight and height to determine whether the body is a healthy weight. Table 1 shows what is considered non-healthy and healthy ranges.

BMI Range BMI Category
Less than 18.5 Underweight at risk of moderate health problems
18.5-24.9 Healthy weight not at risk to serious health problems
25.0-29.9 Overweight at risk of moderate health problems
30.0-39.9 Obese at risk of serious health problems
More than 40.0 Morbidly Obese at risk of serious health problems

Table 1: BMI categories explained.

Obesity is an increasing problem, our nation has lower activity levels and increased calorie diets and we are ‘piling on the pounds’ as a result. A 2014 study showed that more that 1.9 billion adults are overweight and 600 million are obese. This figure has doubled since the 1980s, but why? What has changed since the 1980s that has led to such a rapid weight gain?

Causes of Obesity

There are are a multitude of causes to obesity as it is described as a multifactoral disease. We now live in an obesogenic society, which gives rise to increased weight gain. The changes in society that have led to a rise in obesity include:

  • Increased calorific diets- As the years have passed our diets have increased in processed foods containing saturated fats, sugars/refined carbohydrates. This has led to waist lines ballooning and health declining. Less people are cooking at home from fresh produce, therefore they don’t know what is truly in their food. Less food is home grown and it is more easy than ever to have food delivered to your door. Moreover, eating has slipped down the list of our priorities, we don’t take time to concentrate on our food and so we don’t take time to notice we are full. Overeating is one of the biggest issues in nutrition today.
  • Decreased activity- In addition, to poor dietary intake there has also been a decline in physical activity. Firstly, we have moved from an agricultural to an industrialised world. Less jobs are physically taxing. We have fewer factory workers, builders and land workers, and more desk jobs with very little physical movement. Secondly, technology has taken over, we spend more hours sat watching television and playing games that most other nations. In addition to this small changes such as remote controls and mobile phones have reduced calories burnt by approximately 40kcal per day. Lastly, it has become so costly to stay fit due to the rising cost of gyms and health clubs.

What is the link between brain chemistry and obesity?

What is a craving? Simply put it is a desire for a certain food or food group. This desire is determined by our brain chemistry. Fluctuations in hormones can lead to an addiction to a particular food or food group. Recent research found that there could be a link between brain chemistry and overeating. The brain chemical in question is Serotonin, the ‘happy hormone’. The link isn’t entirely understood but it’s believed to control food intake and is linked to consumption of carbohydrates. High levels of Serotonin in the brain are triggered by drastic peaks in the blood concentration of refined sugars. This creates a sort of “High”. From then on, when carbohydrates are consumed it causes Serotonin to drastically peak, which causes a dysregulation of carbohydrate intake that leads to an engrained need to overeat in order to enhance mood.

By controlling Serotonin levels, or naturally supplementing them, for example with 5-Hydroxytryptophan (5-HTP), it will cut out those persistent cravings for a Serotonin high caused by junk food, processed meals and desserts. Recent studies have shown that targeting and stimulating Serotonin receptor 5-HT6 has been effective in reducing food intake, overeating and body weight.

How to manage Obesity?

The premise of weight loss may sound simple but it’s setting good habits that is the difficult part. Statistics state you must do something seven times for it to become a habit. Nutritionally it’s important to concentrate on good home made meals, packed full of fruit, vegetables, lean meats and wholegrain carbohydrates. Cut out the refined sugar found in processed foods and desserts and break free from your Serotonin induced sugar addiction. For exercise, it is simple, get up and moving, whether it’s an evening stroll or training for a marathon, all forms of movement are value for weight loss. For more information on losing weight please click HERE.

Although, there is very little evidence 5-HTP is thought to be hugely effective in tackling cravings and reducing body weight. 5-HTP is a natural supplement extracted from the Griffonia Simplicifolia plant. 5-HTP in the body is the precursor of Serotonin. Usually the body would go through 3 steps converting Tryptophan to 5-HTP and then to Serotonin. However, when 5-HTP is naturally supplemented the body is able to produce more Serotonin. When taken for dieting purposes 5-HTP will break the vicious circle between carbohydrate consumption and a Serotonin high. One study showed that taking 5-HTP alongside a normal and a calorie controlled diet could generate large losses in weight compared to a placebo under both conditions.

Obesity can rarely be blamed on anything but the person. It’s time to take control and tackle those pesky cravings.

  1. WHO. (1997). Obesity-Preventing and Managing a Global Epidemic.Available: file:///C:/Users/OV/Downloads/WHO_NUT_NCD_98.1_(p1-158).pdf.
  2. WHO. (2016). Obesity and Overweight. Available:
  3. Wurtman,RJ. Wurtman, JJ. . (1995). Brain serotonin, carbohydrate-craving, obesity and depression.. Obesity Research. 3 (4), Pg. 477-480.
  4. Sargent BJ, Henderson AJ. Targeting 5-HT receptors for the treatment of obesity. Curr Opin Pharmacol 2011;11:52-8.
  5. Cangiano C, Ceci F, Cascino A, Del Ben M, Laviano A, Muscaritoli M, Antonucci F, Rossi-Fanelli F. "Eating behavior and adherence to dietary prescriptions in obese adult subjects treated with 5-hydroxytryptophan." Am J Clin Nutr. 1992 Nov;56(5):863-7.
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