“Meta-rules” are a small but powerful way to change your eating habits and keep off unwanted pounds, according to former obese economists Christopher Payne and Robert Barnett. The friends, who once worked together at Bloomberg, used the philosophy to drop a combined 120 pounds.

Payne and Barnett have written a book about their weight loss journey: “The Economists’ Diet.” They say their philosophy, which they adopted from behavioral economist Dan Ariely, applies their knowledge about economics to mindful eating.

“There’s a glut of food, we’re eating too much,” Payne tells NBC News BETTER. “This is how we have to impose eating austerity in order to get our bodies back.”

“Meta-rules” are small rules you establish that dictate how you eat

Whether you make it a rule to only eat dessert once a week, or to ban sugary drinks, “meta-rules” help you lose weight because they reduce decision making about what goes in your stomach, Payne and Barnett say.

“It’s almost like an oath to yourself to take decision and choice out of it,” Payne says. “But in another sense, what we’re talking about is just habits.”

The men give the following tips in addition to applying “meta-rules” to weight loss.

Weigh yourself every morning. This will force you to be conscious of how your eating habits are affecting your weight.

Never waste calories on food you don’t love.

Have two light meals and one square meal per day.

If you know you’re going to eat a large meal later, skip a meal earlier in the day.

Become calorie conscious. You may even want to keep a food ledger and count your calories.

Christopher Payne before and after. Courtesy Christopher Payne, Nadia Ziyadeh

Losing weight takes time

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Payne and Barnett insist “meta-rules” are not a fad diet: they won’t help you lose weight quickly.

“It’s a long-term process about changing behavior for the good,” Payne says.

You do something quick, and then you almost toss it out and go back to your old ways.

Payne says it took him 18 months to lose 45 pounds, or about 2.5 pounds a month. Barnett says it took him over a year to lose 75 pounds.

“We would generally caution against [losing weight quickly] because we don’t think it gives you enough time to instill the habits you’re going to need to [keep the weight off] for the rest of your life,” says Barnett. “You do something quick, and then you almost toss it out and go back to your old ways.”

Robert Barnett before and after. Julia Schmalz, Anne Marie Hathcock

Developing mindful eating habits is more effective than exercise

You might think that exercise is enough to maintain a healthy weight, the authors say, but developing positive eating habits through “meta-rules” outperforms the gym.

“For many of us, [exercise] is not something we’re going to keep up forever,” Payne says. “You need to be able to keep up the sustainable habits.”

“Meta-rules” are about changing your behavior for the long-haul

Both men say “meta-rules” helped them lose weight and keep it off.

“There’s plenty enough to worry about in life, and it just so happens for me the one thing I don’t have to worry about is my weight,” says Payne. “But it’s not that I have some perfect physique — far from it — it’s just good enough, and that’s great.”

Barnett says his blood pressure has gone down and he no longer takes medication.

“I think whenever you can sort of naturally control something like that as opposed to needing a pill, that’s great,” says Barnett. “So hopefully I’ll be around for my children for more years and that kind of thing because of losing weight.”

How to change your eating habits with “meta-rules”

Make some rules: Creating “meta-rules” for mindful eating will help reduce decision making about what you’re going to eat. For example, you might make a rule that you’re only going to drink your coffee black, or that you will only eat out twice a month.

Creating “meta-rules” for mindful eating will help reduce decision making about what you’re going to eat. For example, you might make a rule that you’re only going to drink your coffee black, or that you will only eat out twice a month. Practice patience: “Meta-rules” are not a fad diet. Losing weight is a slow process. Remember: it’s not about being thin, but rather, changing your behavior, which will help keep the weight off.

“Meta-rules” are not a fad diet. Losing weight is a slow process. Remember: it’s not about being thin, but rather, changing your behavior, which will help keep the weight off. Eat well first, exercise second: While exercise is great, it probably won’t help you stay in shape if you’re not also watching what goes in your mouth. “Meta-rules” help keep the weight off even when you can’t make it to the gym.

While exercise is great, it probably won’t help you stay in shape if you’re not also watching what goes in your mouth. “Meta-rules” help keep the weight off even when you can’t make it to the gym. You have to be in it to win it: Whether you’re tired of being overweight or just want to be healthier, “meta-rules” will help you develop healthier habits for the rest of your life.

More weight-loss success stories (and tips to borrow)

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