Obesity Physical and Mental Health Consequences in Ageing

Introduction

Obesity is defined as abnormal or extensive fat accumulation that negatively affects health (Han & Bchir, 2013). According to the World Health Organization (WHO), obesity is defined as Body Mass Index (BMI) ≥ 30 kg/m2 and central obesity as a waist circumference greater than 102 cm in men and 88 cm in women (WHO, 2000). But in older adults, body composition changes that accompany aging make BMI less appropriate for use. This is because BMI relies on muscle mass to influence the ratio of height-to-weight, and aging is accompanied by a decline in muscle mass. BMI also relies on height, and there is often height reduction in older adults due to osteoporosis-related vertebral compression fractures and kyphosis. Better measures in older adults are waist circumference and waist-to-hip ratio. Both correlate well with measures of visceral fat as determined by computed tomography (CT) and with the rates of obesity-related diseases. Waist circumference, which is easy to measure, is a stronger predictor than BMI of mortality in older women (Keller, Shaw-Snyder, & Ainsworth, 2015).

It is a complex multifactorial disease arises from the interactions between genetic, environmental and behavioral factors together with other factors results in energy imbalance and promotes excessive fat deposition (Farooqi et al., 2010). Obesity is now recognized as the most prevalent metabolic disease worldwide, reaching epidemic proportions in both developed and developing countries and affecting all age group (Michalakis, Mintziori, Kaprara, Tarlatzis, & Goulis, 2013). Over the past several decades, the proportion of obese elderly increased. Improvements in health care have contributed to a significant increase in life expectancy and have influenced the growth of the elderly population. Projection indicates that by the year 2020 there will be 470 million people aged 65 and above in developing countries which will be more than double the number of the developed world (WHO, 1992). This increase is accompanied by a similar rise in the occurrence of age- and nutrition-associated diseases including obesity, cardiovascular disease, and diabetes mellitus (Westendorp, 2006). Elderly people who belong to middle and higher income groups are prone to develop obesity and its related complications due to a sedentary lifestyle and decreased physical activity. Obesity is a significant risk factor for coronary artery disease, hypertension, cholelithiasis, diabetes, osteoarthritis (Swami, Bhatia, Gupta, & Bhatia, 2005). The rate of dementia is also higher among obese older adults. Moreover, older persons who are obese (BMI ≥ 30) have a greater rate of nursing home admissions than non-obese seniors (BMI: 18.5 - 24.9) (Salihu, Bonnema, & Alio, 2009). The body mass index associated with the lowest mortality falls within the range of 18.5 to 24.9 in men & women between the ages of 30 and 74 (Stevens, 2000). It was found that BMI of 26 or more is a significant risk factor for diabetes and BMI more than 30 was significantly associated with arthritis and hypertension (Oster, & Maskides, 2005). Thus, with more people surviving in later life, more obese will be living and having certain morbidities as the effect of obesity.