**3.1. Introduction**

Diabetes mellitus is a very common disease among elderly individuals, affecting approximately 20% of older adults aged 65–75 years and 40% of adults older than 80 years [58]. Fifty years and older men and women with diabetes live an average 7.5 and 8.2 years less than nondiabetic individuals [59]. Diabetic individuals are 2 to 4 times more likely to have coronary heart disease (CHD) than nondiabetics, and approximately 70–80% of diabetics are dying from CHD [60]. Elderly diabetics have increased the risk of premature death, functional disability, and comorbidities including hypertension, CHD, and stroke. Elderly diabetics also have a higher risk for various known geriatric disorders including depression, cognitive dysfunction, urinary incontinence, fall-related injuries, and persistent pain [61].

Worldwide lifestyle changes cause elevated prevalence of obesity and urbanization, accompanied with higher predicted prevalence of diabetes, particularly among persons 75 years and older [41]. According to national population estimates, there will be a 69% increase in numbers of adults with diabetes in developing countries and a 20% increase in developed countries between 2010 and 2030. Currently, the highest number of people with diabetes around the world is in the 40–59-year-old age-group; however, there will be slightly more people with diabetes in the 60–79-year-old age-group by 2030 [62]. Nutritional evaluation is suggested for all elderly diabetics at the diagnosis time and regularly thereafter, which provide the determination of patients with undernutrition [63].
