Obesity is a complex chronic disorder that has become a global epidemic (WHO 2000). In 2014, official worldwide estimates indicated that approximately 1.9 billion adults were overweight and 600 million of them were obese. The number of deaths associated with obesity and overweight are higher than with underweight (WHO 2015). Genetic, environmental, 'lifestyle' and psychosocial factors affect energy intake and expenditure, and can influence weight gain (Kopelman 2000). Obesity and overweight are defined as excess body fat that can lead to health impairments (WHO 2015). Adults with a body mass index (BMI: weight in kilograms divided by height in metres squared) between 25 kg/m² and 29.9 kg/m² are defined as overweight and those with a BMI of 30 kg/m² or more are obese. Obesity can be subdivided into class I (30 kg/m² to 34.99 kg/ 1 Glucagon-like peptide (GLP)-1 analogues for normoglycaemic, overweight or obese adults (Protocol)