Overweight is a BMI greater than or equal to 25
Obesity is defined as having a body mass index (BMI) greater than or equal to 30 kg/m2.
**** In 1997, the World Health Organization (WHO) formally recognized obesity as a global epidemic and estimated that the worldwide prevalence of obesity has nearly tripled since 1975. Obesity is a leading preventable cause of death worldwide, with increasing rates in adults and children.
Classification of obesity based on BMI
BMI is a rough calculation of a person’s weight in relation to their height. Other ways of an accurate measures of body fat and body fat distribution include:
- Skinfold thickness tests
- Waist-to-hip ratio
- Screening tests, such as CT scans and MRI scans
Though obesity can be an outcome of various underlying conditions, the most common ones include genetics - which can affect how your body processes food into energy and how fat is stored, aging- which can lead to less muscle mass and a slower metabolic rate, making it easier to gain weight, inadequate sleep- which can lead to hormonal changes that make you feel hungrier and crave certain high-calorie food, pregnancy- as weight gained during pregnancy may be difficult to lose and might eventually lead to obesity.
Certain health conditions can also lead to weight gain, which may lead to obesity. These include:
- Polycystic ovary syndrome (PCOS), a condition that causes an imbalance of female reproductive hormones
- Cushing syndrome, a condition caused by having high cortisol levels (the stress hormone) in system
- Hypothyroidism (underactive thyroid), a condition in which the thyroid gland doesn’t produce enough of certain important hormones
- Osteoarthritis (OA) and other joint conditions that cause pain which limits the physical activity
Comorbidities associated with obesity:
Obesity is a major health problem strongly increasing the risk for various severe related complications.
Relationship Between obesity and Mortality:
**** Obesity is a global disease & according to the world health organization figures, at least 2.8 million people die each year as a result of being obese.
Obesity and Risk of Developing Type 2 Diabetes Mellitus (T2DM) in Male and Female Adults :
A strong association exists between central obesity and T2DM. Both insulin resistance and hyperinsulinemia correlate positively to visceral fat accumulation which constitutes an independent risk factor for T2DM.
Obesity-Related Inflammatory and Procoagulant State:
Weight gain progressively promotes subclinical inflammation in patients with obesity, which is mainly attributed to secretion of various proinflammatory factors.
Obesity and Reproduction:
Obesity can cause dysfunction of the hypothalamic-pituitary-gonadal (HPG) axis in both genders. Obese women present with a wide range of manifestations that extend from menstrual abnormalities to infertility, while obese men can exhibit decreased libido, erectile dysfunction, sub-fertility and more rarely hypogonadism.
Obesity and Cancer Risk:
**** Obesity, particularly central insulin resistance and chronic compensatory hyperinsulinemia. Increased insulin levels induce mitogenic effects and contribute to tumor formation.
Obesity & Covid:
Obesity plays a profound role in risk for death from COVID-19. A meta- analysis revealed that every 1kg/m2 rise in a patient's BMI was associated with a 2 percent increased risk of testing positive for the virus.
Pathogenesis of health problems associated with obesity
Management
Obesity & its wide spectrum of comorbidities can be prevented by the following measures:
- Following a calorie deficit diet.
- Limiting energy intake from total fats and sugars.
- Increasing consumption of fruit and vegetables, as well as legumes, whole grains and nuts.
- Engaging in regular physical activity (60 minutes a day for children and 150 minutes spread throughout the week for adults).
References:
- Bray, G. A. (2004) ‘Medical Consequences of Obesity’, The Journal of Clinical Endocrinology & Metabolism, 89(6), pp. 2583–2589. doi: 10.1210/JC.2004-0535.
- Kopelman, P. G. (2000) ‘Obesity as a medical problem’, Nature 2000 404:6778, 404(6778), pp. 635–643. doi: 10.1038/35007508.
- Ogden, C. L. et al. (2007) ‘The Epidemiology of Obesity’, Gastroenterology, 132(6), pp. 2087–2102. doi: 10.1053/J.GASTRO.2007.03.052.
- Wright, S. M. and Aronne, L. J. (2012) ‘Causes of obesity’, Abdominal Radiology 2012 37:5, 37(5), pp. 730–732. doi: 10.1007/S00261-012-9862-X.
