Today, according to the CDC, more than one-third of us in the United States are considered obese. If you find that number startling, consider that a recent Washington Post article stated that nearly three-quarters of Americans aren’t saving adequately for retirement. While we as a country spend billions of dollars on diets, gyms and the next weight loss miracle pill, there is a rather simple recipe for weight loss: eat less and move more. In a time where so many are willing to spend money on weight loss, more and more people are looking for lower cost options when it comes to their finances. The issues of both weight gain and lack of savings, though, are primarily a direct result of the same thing: our own behaviour.

While we all know that eating that doughnut or fast food dinner isn’t in our best interest, sometimes our financial behavioural problems may not be so obvious. From 401(k) contribution amounts to changing investment allocations to where to even begin saving, a multitude of challenges face us that are far more complex than simply skipping that side of fries.

We all know the person with the iron will, who chooses the salad over the burger and the gym over happy hour, who, despite all life’s temptations and commitments, maintains a healthy lifestyle. The same can be seen in the financial world: the intelligent investor who carefully selects 401(k) and investment allocations, utilizes dollar-cost averaging irrespective of market performance, and always seems to make the right financial decisions.

Now imagine for a moment being armed with a personal trainer, nutritionist and chef; how much easier would it be having people to hold you accountable as you work towards your weight loss goal? The same can be said of your financial life. With a swell of information now at our fingertips, the increasing popularity of low-cost robo-advisors and an abundance of financial media, it becomes increasingly more tempting to manage your finances alone. While not necessary for everyone, like the weight loss team assembled above, a group of financial professionals surrounding you could certainly make things easier.

Behavioural finance, while a relatively new field, combines psychological theory with economic principles to better understand why people make irrational choices as it pertains to their finances.

The prevailing thought for many choosing to manage their own investments is, “I can do it for less if I do it myself.” Taken at face value, this is true. Low-cost index funds are undoubtedly cheaper than having an advisor manage your accounts. However, the underlying dilemma becomes price versus cost. Price is the fee of the professional team assembled; cost is what’s really at stake. Though it may seem like a rather harmless decision in the moment, the wrong investment choices can potentially cost a person millions of dollars when compounded over time. This is the true cost of our own behavior.

Dalbar, an auditing and research firm specializing in financial services, found in 2015 that over the previous 20 years the average equity investor’s annualized rate of return was 4.67%, while over the same timeframe the S&P 500 Index saw an annualized return nearly double that, at 8.19%. W hile that is not an advisor managed account but the S&P itself, it illustrates how investor returns dramatically lag the market as a whole due in part to behavioral issues ranging from stock picking to market timing.

Using the above numbers from Dalbar, the investor rate of return is 4.67%, (assuming there is no fee) vs. the S&P’s 8.19% return, less a 1% advisor fee. Using these figures, an initial $100,000 investment managed on your own over 20 years would grow to roughly $250,000 on average vs. about $400,000 if following the S&P. The price you intended to save was $1,000, but you actually cost yourself $150,000!

I am fond of telling my clients I earn my fees in down-market years, not up-market years, which always draws a puzzled look from those sitting across from me. I present a hypothetical situation. “Suppose you leave my office right now and go to the nearest shopping mall. You have no form of payment other than your most recent investment statement. Pick out a dollar amount of goods equal to the number on your statement, and try to pay with said investment statement. What do you think would happen?” My clients usually laugh and say they would receive nothing because “it’s just a piece of paper,” to which I always respond, “Exactly. It’s just a piece of paper, but the moment we panic we can turn paper losses into real losses.” This resonates with a number of clients thinking back to what many of them experienced in 2008. While some weathered the storm and rode the market back to all-time highs, many others moved to the sidelines, scared to brave the choppy investment waters, losing almost a decade of returns.

Whether it be trying to predict the ups and downs of the market, an aversion to loss, speculating on the next hot stock, or a host of other impulses, it doesn’t take much to derail a well-intentioned financial plan. Having someone by your side through the inevitable ups and downs of the market can be an invaluable way to mitigate our own behavioural impulses, which are often driven by fear, anxiety, and yes, our own greed.

Just as it’s hard to pass on all those foods we know we shouldn’t be eating, correct financial choices aren’t always easy. Those of us who lack the necessary discipline will never see any real results. Remember, the same lack of discipline that’s expanding your waistline could also be reducing your retirement bottom line.