Modern society today is facing an epidemic of overweightness and obesity, as one-third of the world population is affected; and this ratio is on the rise. During the past two decades, the number of children who are overweight has doubled. Characterized by an abnormal or excessive fat accumulation, obesity is considered a serious threat to health. Both general obesity and abdominal obesity increase mortality risk. Usually, body mass index (BMI), which is a simple index to classify overweightness and obesity in adults, is calculated by dividing weight in kilograms by the square of the height in meters (kg / m2). As defined by the World Health Organization (WHO), BMI ≥ 25 is considered overweight and a BMI ≥ 30 is considered obese. In 2005, approximately 1.6 billion people older than 15 years in the world were overweight and at least 400 million people suffered from obesity and at least 20 million children younger than 5 years were overweight. Nowadays, overweightness and obesity is increasing in low and middle income countries.
The main cause of obesity and overweightness is an imbalance of caloric intake and caloric output. Obesity can lead to serious consequences, such as cardiovascular diseases, diabetes, musculoskeletal disorders such as osteoarthritis and cancers such as endometrial cancer, breast and colon cancer.
For weight loss and treatment of obesity there are several pharmacological and non- pharmacological treatments. However, none of these treatments have definite outcomes. According to one research, compounds extracted from citrus can be used as human food in order to lose or weight, as well as to improve one’s physique and to increase lean muscle mass. In order to reduce or control weight, such compounds can be used with or without restricting the amount of the calories taken or burned. The noted mechanisms of effect mainly include the increase of thermogenesis (increasing metabolic rate and facilitating lipolysis) and also suppressing hunger. The latter is especially more manifest in large amounts in individuals in whom high concentrations of active ingredients readily pass the blood-brain barrier.
In a study to evaluate the effects of Lemon Essential Oil on weight loss in mice. it was administered either alone or in conjunction with ketotifen (an antihistamine that causes weight gain) during a course of 45 days. There was an apparent increase in body weight and food intake in the mice that had received ketotifen in comparison to those in the control group. Loss of appetite might possibly explain the reason for a reduction of food intake and body weight in those mice treated with lemon essential oil. Interestingly, administration of the lemon essential oil in conjunction with ketotifen caused significant suppression of body weight gain and caused weight loss in rats. Based on the data obtained from this study, lemon essential oil plays an important role in weight loss and it can be very effective in the treatment of obesity resulting from drugs and related diseases.