Let's see. Do I want an investment adviser or a financial adviser to help plan for retirement? A variable annuity, fixed annuity, or no annuity at all? How about stashing savings in an S&P 500 index fund - they're all the same, right?

I don't have vertigo, but whenever I consider my options for retirement saving, my head spins. Then I heard about President Obama's AARP speech last week and wondered if the diagnosis - and a simple, straightforward treatment - had been sitting around untried all along.

That's how it looks to Barbara Roper, director of investor protection at the Consumer Federation of America. For years, Roper has pushed a theme that the Obama administration now embraces, even if it shies away from using a legal name for it - fiduciary duty - as inscrutable to most people as a generic drug's.

I caught up with Roper last week to ask why she and Obama are focused on the same answer for what ails this key corner of our financial system: requiring all who offer retirement advice to act in the best interests of their clients, even if it means less profit for the advisers.

The problem they're trying to address is vast, with Social Security promising a limited safety net and the demise of most fixed-benefit pensions. We're increasingly reliant on private savings. Yet some people's prudence gets undermined by a Wild West system full of lax and confusing rules and little enforcement.

For many of us, it's not only hard to distinguish among the financial products available, it's even hard to tell which advisers to trust and which to treat warily.

Obama framed the problem simply: "Right now," he said, "there are no uniform rules of the road that require retirement advisers to act in the best interests of their clients." Though the proposed rules from the Labor Department aren't yet public, Roper says it's clear that Obama wants to make that key requirement - a fiduciary duty - finally apply across the board.

Investment adviser or financial adviser? Turns out that the first one already has a fiduciary duty, according to the Securities and Exchange Commission: "a fundamental obligation to act in the best interests of your clients and to provide investment advice in your clients' best interests."

That's not true of a "financial adviser" - a term used by insurance brokers who aren't under the SEC's purview, and also by stockbrokers and mutual-fund firms.

"There's overwhelming survey data that suggests that people can't distinguish between investment advisers and broker-dealers," Roper says. Nor do fact sheets or financial education seem to matter. "You can't educate or disclose your way out of this problem."

But the problem is far too big to ignore. A new report from the Council of Economic Advisers puts the damage caused by advisers' conflicts of interest at a staggering $17 billion a year.

One example comes from those S&P 500 index funds - which are definitely not all created equal.

In a 2013 report, Roper said some funds charged far more than the low-fee versions sold by companies like Vanguard, Fidelity, or T. Rowe Price. One version of the Rydex S&P 500 Fund, with about $349 million invested, had a net expense ratio of 1.5 percent - "roughly 20 times the expense ratio on the Fidelity fund," Roper told the SEC.

"You can't say you're paying for better research or management," she says. Instead, you're paying for the broker-dealer's conflict of interest - because the funds compete by offering better deals to the brokers who sell them.

Like Obama, Roper hastens to note that many professionals give the best possible advice, anyway.

"It's no great mystery that brokers respond to those incentives," she says. "The surprise is when they don't - when they stand up to management and work in the best interests of the investor."

The new Labor Department rules - if not beaten back by lobbyists, as happened to an earlier version in 2011 - would support those upstanding advisers by making it everybody's duty to act in their clients' best interests.

New rules can't block all conflicts of interest, or make my head stop spinning. But they're the right place to start.