Claiming that this loss could amount to more than £40,000, chartered accountant Rachel Holmes said the Westminster government's "raid" on pensions could have a "devastating" effect on young people when they stop working.
In a release issued by Yes Scotland she said anybody taking up employment at 18, who would have been expecting to retire at 66, would have paid National Insurance contributions for 48 years in return for about 10 years of pension for men and 14 years for women, based on Scotland's average life expectancy.
But under Westminster Government plans, today's 18-year-olds will have to work until they are 70 before qualifying for the state pension. That means they will be contributing about 8% more in National Insurance but getting 40% less in pension, which could equate to more than £40,000.
Ms Holmes said: "The impact of the increase in the state pension age is much more severe than people realise and yet again, under the Coalition's continuing austerity programme, it will be another section of society that will be hardest hit - our young people who are already the first generation in many decades to be worse off than the generation before them."
She pointed out that the hardship would not affect the wealthiest who can pay £50,000 annually into a pension pot and receive tax relief. "'All in it together' sounds rather hollow in that light," she said. "Surely, like other small progressive independent nations, Scotland can do better. Surely we want to be a nation who looks after our elderly without the spectre of poverty looming ever larger."
But a Better Together spokesman said: "At a time where countries across the world are facing up to the challenges caused by the demographic timebomb, the SNP are trying to tell us that Scotland would, somehow, uniquely, be able to dodge any and all problems.
"The independent and impartial Institute for Fiscal Studies say that if we go it alone, our rapidly ageing population, the decline in the number of people of working age and the decline in oil revenues would mean tax rises, service cuts or a combination of the two. The SNP response is to say that they are wrong and that, actually, money will fall from the skies. It just isn't credible."
Chris Leitch, head of employment law at Tods Murray, said: "If Scotland votes Yes next year and the White Paper plans become a reality, Scotland could arguably be a more attractive place to be a pensioner than the rest of the UK."
Yes Scotland Chief Executive Blair Jenkins said: "The cost of a No vote is becoming painfully clear. The impact of George Osborne's pension plans, particularly on young people and on those whose state pension date is being extended every further at a time when they should be looking forward to the rewards after long years of work, is truly shocking."
Deputy First Minister Nicola Sturgeon said: "Scotland's lower life expectancy means that people experience fewer years in retirement than the UK average.
"That is why we are far from convinced by Westminster's rush to make people work for longer and for less."