Losing weight is one thing, keeping it off is another.

In fact, research suggests that 80% of people who lose at least 10% of their body weight regain everything they lost, if not more.

So it's extra impressive when someone manages to sustain their weight loss.

One such person is Carter Good: In 2011, he weighed 305 pounds.

A post shared by Carter Weight Loss Coach (@cartergood)Apr 29, 2020 at 7:18am PDT

But within a year, he'd lost 100 pounds, and the year after that he lost another 40. Nine years later, Good hasn't regained the weight.

The 25-year-old from Austin, Texas, who is now a weight loss coach and qualified personal trainer, recently shared the 10 most important lessons he's learned about sustainable fat loss in an Instagram post.

Carter Good is now a qualified personal trainer. Carter Good

"I know that my weight loss is inspiring ... and so every time I share, I try to use it as a way to encourage and educate others on the right way to lose weight and get healthy," Good told Insider.

Here are the 10 lessons Carter Good learned through losing 140 pounds, and keeping it off.

Good learned the hard way about how to lose weight right.

"Initially, it was all through crazy restriction and cardio," he told Insider, explaining that he found a diet plan online and just cut the portions in half, which he now realizes was "not smart."

"Along with eating a very low-calorie diet, I would use the elliptical for 60 to 75 minutes every single day," he added.

Although this approachdidlead to weight loss, it wasn't sustainable because it was too restrictive.

"It took one to two years of education and mental growth to find more balance between my fitness goals and other life goals," he said.

It's essential to make the process enjoyable.

"Regardless of how long it takes you to lose weight, you're going to spend a much longer time maintaining a lean and healthy body," Good wrote on Instagram.

Good encourages people to understand that your weight is a tool, not your identity.

"People come to me with the goal of losing a certain amount of weight," he said. "Maybe it's a weight they used to be at, or maybe a weight their doctor recommends reaching.

"Either way, the number isn't the goal ... it's what happens when you get down to that number."

So instead of thinking about the number on the scale as the goal, focus on the habits, strategies, and routine you'll develop on the way.

Although the key to sustainable weight loss is creating a healthy lifestyle you enjoy and can thus maintain, and it's never wise to cut out every food you enjoy, youwillhave to make some changes, Good said.

"Most people struggle with their weight," he wrote.

"If you prioritize fitness, you're going to have to be disciplined. You'll often have to skip the next round of beers or pass on the late-night slice.

"That doesn't mean you can't have fun, though."

It's important still to enjoy your diet. Carter Good

The sad truth is that peanut butter, while being nutrient-dense and delicious, is also very energy-dense and easy to overeat.

"It's sad, I know," Good wrote.

"But for real. Measure that s---."

As healthy as kale and celery may be, there's no point forcing yourself to eat them if you don't enjoy them.

"Eat whole foods you enjoy," Good wrote.

"Include 'fun foods' you enjoy. You should never resent your diet."

Good wrote that as he lost weight, his cravings didn't vanish but he got "better at delaying gratification for a greater reward."

"People who are successful in fitness (and other areas of life) are the people who are able to delay gratification. Simple as that," he explained to Insider.

"Oftentimes with fitness, the 'easier' and 'more enjoyable' choice you make in the moment isn't the one that'll lead to being lean and healthy."

For example, watching Netflix on the couch is easier than going to do a workout.

"Part of becoming someone who makes fitness a priority is being able to make the harder choice in the moment that leads to a greater reward in the future," Good said.

"It's not an easy mindset to train, but the more consistent you can be from the start, the easier it gets especially once you start seeing results!"

Don't force yourself to eat healthy foods you don't like. Carter Good

"Ignore them," Good wrote.

You may be surprised by how people respond to your weight loss.

"Just like anything worth having," Good wrote.

Don't rush the process.

Good wrote that investing in your health and making fitness a priority is worth it because not only does it lead to feeling and looking better, but it allows you to do better for the people in your life.

"Losing weight has taught me about hard work, discipline, and delayed-gratification, which has helped me in so many other areas of my life," Good said.

"For example, if it wasn't for fitness, I would have never believed in my ability to build and grow my own business.

"It's also taught me that I can accomplish anything I want in life. I just have to be willing to work hard, be patient, and refuse to quit."

Read more:

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You're probably not experiencing 'starvation mode' if your weight loss has stalled here's what could be happening instead

I've been overeating in lockdown out of anxiety and loneliness. How do I stop myself turning to food for comfort?

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Fat loss lessons one man learned losing 140 pounds and keeping it off - Insider - INSIDER