Background: The older adult population is increasing and depression is commonly observed within this community. This study is one of the firsts assessed depression and its risk factors in a healthy well-nourished over-55 years old population.Method: Beck Depression Inventory-13 (BDI-13) was used to determine depression in 766 individuals. a full report of socioeconomic factors was gathered. Lifestyle and physical activity were assessed using Health Survey Questionnaire 36-Item Short-Form and International Physical Activity Questionnaire, respectively. The dietary nutrient intake was recorded using an adjusted dietary recall.Result: A total of 58% of the population had mild to severe depression. The differences between depression groups for age, gender, SF-36 quality of life scores, and nearly all the social-economic factors were significant. females (OR=2.229 (95%CI:1.641-3.026), p<0.005) and higher age was associated with depression (OR=1.073 (95%CI:1.049-1.097), p<0.005). The impact of age, physical activity, having sport, economic level and smoking on depression were independent of all other factors. most nutrients and energy inversely associated with depression (protein (p=0.043), fiber (p=0.037), iron (p=0.041), vitamin B6 (p=0.011) and caffeine (p=0.009) was independent from the energy intake). The predictor decision tree model for depression according social-economic factors is also illustrated.Conclusion: Depression can be prevalent in a nearly healthy population. Many factors can increase the risk of depression. Currently working in males and having sport, economical level, and living with someone in females were the main depression predictors. The impact of protein, fiber, iron, vitamin B6, and caffeine on depression was independent of energy intake.