2 formerly obese economists who lost a combined 120 pounds in 18 months relied on a controversial weight-loss strategy

Courtesy of Simon and Schuster

Rob Barnett, co-author of "The Economists' Diet,"before and after losing 75 pounds in 18 months.

• Christopher Payne and Rob Barnett are the authors of "The Economists' Diet."
• In the book, they argue that, if you're trying to lose weight, you need to step on the scale every day. Their argument is supported by some recent research.
• But some experts say weighing yourself daily can be confusing and demotivating.

The way Christopher Payne sees it, when you're trying to lose weight, "You're basically a scientist of your own body."

Payne is the author, along with Rob Barnett, of the book "The Economists' Diet: The Surprising Formula for Losing Weight and Keeping It Off," in which they teach readers how to use fundamental economic principles to shed pounds, just like they did.

At different points in their lives, Payne and Barnett were both overweight and successfully got themselves to a healthier place. Payne lost 45 pounds in 18 months; Barnett lost 75 pounds in 18 months.

Payne made the comment about being a scientist of your own body to defend one of the more controversial weight-loss strategies in the book: weighing yourself every day. The idea is that you weigh yourself in the morning, see whether the number has gone up or down, reflect on what you ate the day before, and tweak as necessary.

In the book, the authors cite research that links weighing yourself every day with losing weight.

In one 2015 study, published in the Journal of Obesity, researchers tracked 162 overweight adults over the course of two years.

Results showed that participants who weighed themselves daily and received visual feedback about their weight trajectories lost more weight than participants who didn't weight themselves as frequently.

The first group was also better able to maintain the weight loss. And it didn't matter how exactly the participants went about trying to lose weight.

Interestingly, men in the study lost significantly more weight than women did - though the researchers can't explain why.

To be sure, as The Washington Post pointed out, participants might have felt greater pressure to keep the weight off knowing the researchers would be keeping tabs on them. Meaning you might not see the same success as they did.

Another study, published 2016 in the International Journal of Obesity, yielded similar findings in women who weighed themselves frequently.

It's unclear exactly why weighing yourself every day may help with weight loss. In a statement, a co-author of the 2015 study said, "We think the scale also acts as a priming mechanism, making you conscious of food and enabling you to make choices that are consistent with your weight."

Some experts take issue with the idea that you should weigh yourself so often

Still, other experts advise against weighing yourself every day.

Moran Cerf, a professor of business and neuroscience at Northwestern University who has been studying decision-making for over a decade, told Business Insider's Chris Weller that people should weigh themselves just once a week. Your weight can fluctuate by a few pounds every day, Cerf said, and stepping on the scale so often can cause confusion.

One dietitian told USA Today she didn't recommend daily weigh-ins for most clients.

"You can get lost in those numbers and start to identify your self-worth with what's on the scale," she said.

I mentioned to Payne and Barnett that weighing yourself daily sounded like a version of the Quantified Self Movement, which focuses partly on learning more about your body through self-tracking.

Payne said it's similar, but "much more simplistic." In this case, all you're tracking is your weight - not how many steps you take, or how many calories you ingest, or anything else.

Barnett argued that if your weight is what you're trying to control, that's the only thing you should keep tabs on.

He also addressed the emotional piece of weighing yourself so often. When he was at his peak weight - about 250 pounds - he said, "I didn't want to know the number."

Ultimately, Barnett put it in very frank terms.

"Your obesity - or lack thereof - it's not a secret to anyone," he said. "You should get acquainted with that number."

He added: "It really is a life-changing thing to add this to your daily routine."