Go to the page content

Lifestyle intervention and obesity management

The complexities of the pathophysiology of obesity

According to the International Classification of Diseases, obesity is a chronic disease caused by a multifactorial aetiology including genetic, metabolic, behavioural, psychological and environmental factors.1,2 These factors together with the pleasure we derive from food (hedonic factors) can all influence energy balance, which in turn can lead to weight gain.3 Once established, powerful neuro-hormonal factors effectively defend the body against weight loss, thereby often making obesity a lifelong problem, where weight regain (or relapse) is the rule, rather than the exception.3

Metabolic adaptations to weight loss

Our bodies are programmed to respond to weight loss with weight regain.3-7 Weight loss alters the body's homeostatic system,8 which controls appetite, energy intake and energy expenditure, causing the body to increase hunger and lower the metabolic rate – this process is known as metabolic adaptation.8,9

Maintaining weight loss is challenging

A review of 14 long-term studies showed that one to two thirds of people with obesity regained more weight after weight loss achieved by dieting.10 Furthermore, the ACTION IO study* found that  81% of people with obesity have engaged in one or more serious weight loss attempts; however, only 11% were able to maintain a 5% weight loss for one year or more. 11

Infographic showing mean weight change of diets.

Visual adapted from Mann T, Tomiyama AJ, Westling E, Lew AM, Samuels B, Chatman J. Medicare's search for effective obesity treatments: diets are not the answer. Am Psychol. 2007;622(3):220–233.

Why diets alone don't work

Maintaining weight loss is challenging for people living with obesity, and findings such as that from the ACTION IO study show that patients living with obesity have the will to address a conversation about their weight.11

To understand what the effective strategies for obesity management are, we need to consider physiological, psychological and biological factors of obesity. Although lifestyle intervention continues to be key in the management of obesity, increasingly patients require pharmacological adjuncts in order achieve or maintain weight loss.12 It is also crucial to understand the multiple systems involved in the pathophysiology of obesity, and interventions to tackle these could be essential in providing lasting weight loss.

Download our 'Sustaining weight loss can be hard' leaflet below to help educate your patients about the potential challenges of effective weight management and share it with medical colleagues to support their daily practice. 

*The Awareness, Care and Treatment in Obesity MaNagement – an International Observation (ACTION IO) Study is the first international study to investigate barriers to obesity management among people with obesity and healthcare professionals in 11 countries worlwide, including Australia. A total of 14,502 people with obesity and 2,785 healthcare professionals completed the survey.11

Access further information and resources about Novo Nordisk treatments


  1. International Statistical Classification of Diseases and Related Health Problems (11th ed,; ICD-11; World Health Organization, 2019).
  2. Sanyaolu A, Okorie C, Qi X, Locke J, Rehman S. Childhood and Adolescent Obesity in the United States: A Public Health Concern. Glob Pediatr Health. 2019;6:2333794X19891305.
  3. Gadde KM, Martin CK, Berthoud HR, Heymsfield SB. Obesity: Pathophysiology and Management. J Am Coll Cardiol. 2018;71(1):69-84.
  4. Schwartz A, Doucet E. Relative changes in resting energy expenditure during weight loss: a systematic review. Obes Rev. 2010;11(7):531-47.
  5. Sumithran P, Proietto J. The defence of body weight: a physiological basis for weight regain after weight loss. Clin Sci (Lond). 2013;124(4):231-41.
  6. Rosenbaum M, Leibel RL. Adaptive thermogenesis in humans. Int J Obes (Lond). 2010;34 Suppl 1:S47-55.
  7. Rosenbaum M, Kissileff HR, Mayer LE, Hirsch J, Leibel RL. Energy intake in weight-reduced humans. Brain Res. 2010;1350:95-102.
  8. Greenway FL. Physiological adaptations to weight loss and factors favouring weight regain. Int J Obes (Lond) . 2015;39(8):1188-96.
  9. Lenard NR, Berthoud HR. Central and peripheral regulation of food intake and physical activity: pathways and genes. Obesity (Silver Spring). 2008;16 Suppl 3:S11-22.
  10. Mann T, Tomiyama AJ, Westling E, Lew AM, Samuels B, Chatman J. Medicare's search for effective obesity treatments: diets are not the answer. Am Psychol. 2007;62(3):220-33.
  11. Caterson ID, Alfadda AA, Auerbach P, Coutinho W, Cuevas A, Dicker D, et al . Gaps to bridge: Misalignment between perception, reality and actions in obesity.  Diabetes Obes Metab . 2019;21(8):1914-24.
  12. Gonzalez Jimenez E. Obesity: etiologic and pathophysiological analysis. Endocrinol Nutr. 2013;60(1):17-24.





Was this valuable for you?

Related articles