Energy-restricted, diets using whole foods that replace variable amounts of carbohydrate with moderately higher intakes of protein and healthy fats can improve weight loss and correct disordered metabolism for people with lifestyle related disease, including Type 2 diabetes (T2D). However, as the scientific evidence evolves it is clear there is ‘no one-size-fits all’ eating pattern for weight loss, or maintenance of health. Moreover, much of the highest-quality evidence from randomized, controlled, trials is limited people aged less than 65 years and there is a paucity of research in people aged 65 years and older. For this specific segment of our population, the use of traditional energy-restricted diets is of concern because weight loss tends to acerbate loss of muscle mass, strength and function, which already occurs more rapidly with advancing age. This will presentation provide an overview of the latest research from our group, including research-to-practice trials, that have examined the effects of eating patterns varying in their quantities and sources of carbohydrate and protein, on outcomes including weight loss as well as other metrics of good health and quality of life. It will also highlight findings from two systematic reviews with meta-analyses conducted by our group that indicate increased dairy intake (as foods or supplements) can assist with optimising body composition. Finally, the challenges of translating these findings into ‘real-life’ weight and metabolic management programs for adults with cardiovascular disease and T2D, and particularly for those aged 65 years and older, will also be discussed.