Some 210,000 people in Scotland were unemployed last year – an 80% rise on the low point of mid-2008.
Almost half of this rise was among those aged under 25, a report by the Joseph Rowntree Foundation (JRF) has found, with 90,000 young Scots now without work.
JRF noted "shocking inequalities" in the health of Scots depending on their incomes.
It also identified a significant rise in those resorting to part-time work, with a rise of 60,000 part-time workers recorded between 2008 and 2012. The number in full-time work fell by 120,000.
The number of people turning to part-time hours who want a full-time job rose from 70,000 in 2008 to 120,000 in 2012.
Anti-poverty groups have demanded government action as the report warns the independence debate must not obscure "the need for policy development to tackle poverty issues that will exist whatever decision the Scottish people take in 2014".
Julia Unwin, chief executive of the JRF, said: "This report presents clear and unambiguous evidence of the poverty levels among working-age adults, rising numbers of people working part-time for want of a full-time job, high unemployment among young people and some shocking statistics on the health of a nation.
"Not to act upon these findings risks condemning this and future generations to a cycle or poor health and no wealth."
The research, carried out for JRF by the progressive think-tank The New Policy Institute, said the number of children living in poverty in Scotland fell from 340,000 to 220, 000 (21%) in the first decade of the new millennium.
However, the number of childless families on low incomes rose from 125,000 to 150,000 in the four years to 2012.
According to the research, a boy born in the most deprived 10% of Scotland has a life expectancy of 68, eight years below the national average and 14 years below boys born in the least deprived areas.
For girls born in the most deprived 10%, life expectancy is 76, four years below the national average and eight below that of girls in the best-off 10%.
In the poorest communities, cancer mortality rates have barely changed despite improvements in the national picture.
While there was a steep fall in deaths from coronary heart disease in the poorest parts of Scotland from about 150 per 100,000 in 2000 to about 100 per 100,000 in 2009, the rate is still twice the Scottish average.
The report said the findings revealed real and growing problems, adding: "They are problems that cannot wait."
Barnardo's Scotland called for action to support young people, while predicting that child poverty levels would rise sharply in Scotland. "Tackling child poverty must be a priority whatever the government is in power," a spokeswoman said
Children in Scotland chief executive Jackie Brock said: "The findings reveal Scotland has a long road to travel if we are to tackle poverty and inequality."
John Dickie, head of the Child Poverty Action Group in Scotland, said politicians needed to address the issues in the report urgently, adding: "Rising poverty, increasing inequality and fundamental attacks on our social security will be the backdrop to the independence referendum."
Citizens Advice Scotland chief executive Margaret Lynch said the report's findings were supported by the fact Citizens Advice Bureaux are seeing more people in crisis.