The Shape Of Training report by Professor David Greenaway said doctors have to care for many more patients with chronic illnesses who often have several health problems at once.
It recommends a "better balance" between doctors trained to provide care across a general specialty area and those working on much more detailed specialised care.
The report, published by the General Medical Council, was broadly welcomed by professionals but some expressed concern doctors would lack the right skills.
Dr Rosemary Hollick, chairwoman of the Royal College of Phyisicians of Edinburgh Trainees & Members' Committee, said: "We believe completely there has to be an expansion of general medical training, involving greater exposure for all medical trainees to medicine for the elderly.
"However, this should be undertaken in tandem with expansion in the medical specialties, as many specialties are already operating beyond capacity and could not cope with a reduction in numbers to support an increase in generalists."
Dr Frank Dunn, president of the Royal College of Physicians and Surgeons of Glasgow added: "While there is much to commend in the report, we remain concerned about achieving the right balance between service and training."
Under the plans, doctors will undertake the two-year foundation programme following graduation.
A Scottish Government spokesman said: "We welcome Professor Greenaway's report as it provides a real opportunity to plan the future training of doctors to better meet the needs of Scotland's patients."