Krupa Shah, MD, MPH, Geriatric Fellow, Washington University at St. Louis, Division of Geriatric and Nutritional Science, St. Louis, MO, USA.
Dennis Villareal, MD, Associate Professor, Washington University at St. Louis, Division of Geriatric and Nutritional Science, St. Louis, MO, USA.

Obesity is associated with significant morbidity and mortality. In older adults, obesity can exacerbate declining physical function and quality of life that often accompanies aging, and can cause frailty. The value of treatment for obesity in older adults has been under debate because of the uncertain effectiveness of obesity therapies in this population as well as the potentially harmful effects of weight loss. However, current evidence shows that weight-loss treatment improves physical function and quality of life, and also eases the medical complications associated with obesity in older adults. Therefore, moderate weight loss that minimizes muscle and bone loss is recommended for obese older adults who have functional decline or medical complications.
Key words: obesity, body mass index, metabolic syndrome, weight loss, lifestyle modification.

Isabelle J. Dionne, PhD, Faculty of Physical Activity and Sports, University of Sherbrooke; Research Centre on Aging, Geriatric Institute of Sherbrooke University, Sherbrooke, QC.
Martin Brochu, PhD, Faculty of Physical Activity and Sports, University of Sherbrooke; Research Centre on Aging, Geriatric Institute of Sherbrooke University, Sherbrooke, QC.

There is a high prevalence of obesity in older adults up to the age of 80. While women generally gain body weight during the menopausal transition, men tend to accumulate an excess of fat mass earlier in life for as yet unknown reasons. Consequently, an increasing proportion of older adults are now obese. Obesity’s association with metabolic diseases such as metabolic syndrome, type II diabetes, and cardiovascular disease is widely recognized. However, recent evidence shows that, in older adults, obesity is also related to functional impairment and decreased quality of life. This review addresses the actual prevalence and definition of obesity in older adults, the energy-balance equation, and the known consequences of obesity. Finally, the heterogeneity of obesity in older adults regarding its association with metabolic diseases and functional capacity will be discussed, as well as how obesity treatment should be conducted in this population.

Key words: obesity, metabolic syndrome, diabetes, weight loss, impaired functional capacity.

Daniel Tessier, MD, FRCPC, Professor, Head of Geriatric Service, Sherbrooke Geriatric University Institute, Sherbrooke University, Sherbrooke, QC.

The concept of insulin resistance is a major field of interest in the medical literature. The basic science research has significantly increased our knowledge of this phenomenon, which has become a silent killer in our society. The main factors involved in insulin resistance are obesity (mainly abdominal), lack of physical activity, loss of muscle mass and secondary diminution in insulin action followed by diabetes mellitus. The changes in lifestyle and diet observed in many older subjects increases the risk of insulin resistance and diabetes. This paper will underline the main elements for primary and secondary prevention of insulin resistance in older adults.
Key words: insulin resistance, older adults, diabetes mellitus, obesity, free fatty acid, pharmacotherapy.