It is estimated that by 2050 there will be 2 billion people aged 60 years and older in the world. The evidence base for the health benefits of good nutrition and physical activity, as well as weight loss among overweight and obese adults, is growing and a number of policies and guidelines are available to guide health professionals in serving older people at various stages of the lifecycle. There are many potential influences on dietary habits including individual factors, families and friends, community characteristics, the food and supplement industry, and public policy. This review focuses on the evidence base for factors influencing diet in older adults, food insecurity, Na, vitamin D, vitamin B12, protein, obesity and the benefits of energy restriction in overweight and obese older adults. Research is needed to continue to increase the evidence base for appropriate ways to improve diet and health in older people. Also, much of the available information is from the US, so there is a need to conduct research in other areas of the world.