Noom is a popular dieting app, but does it work? Here's what you should know before signing up

• The Noom app sets a daily calorie limit and offers supportive networks to aid weight loss.
• Early studies indicate that nearly 80% of people who use Noom will lose weight.
• However, personal accounts that you can find online suggest Noom isn't all it's cracked up to be.

The Noom diet is a modern approach to dieting that uses a phone app to connect you to a supportive network to aid weight loss.

"Studies have shown that those who join a program with a friend/group rather than themselves are more likely to lose weight and also keep it off at six months," says John Higgins, a sports cardiologist at McGovern Medical School at the University of Texas Health Science Center at Houston.

While the overall premise of Noom is admirable, personal reports from members and coaches suggest the reality is a disappointment for some. Here's a breakdown of Noom and some final recommendations on what you should consider before signing up.

Research behind the Noom diet

Rather than a quick fix, the Noom app tries to change users' behavior over the long term.

Because Noom is relatively new, there aren't many studies evaluating how effective it is:

• A 2016 study found that about 78% of the 35,921 participants who used Noom lost weight over an 18-month period.
• And a 2017 study found that Noom appeared to help people lose weight over a six-month period and that getting feedback from their support group encouraged people to log their food more often in the app.

How much Noom costs

Noom isn't free. When you sign up, you have numerous payment options starting with an annual membership for $199 or a monthly plan at $66.35 a month.

How the Noom diet works

If you're trying Noom to lose weight, then after downloading and launching the app you'll create a weight-loss plan, where you'll provide personal information including your weight-loss goals, activity levels, and location.

Dieters will then start logging their food and exercise in the app to keep track of their total calorie intake for the day.

As you log your food, you'll notice that Noom has a color-coding system that categorizes food into three colors: green, yellow, and red.

• Green foods are foods with the least amount of calories per ounce and they include mostly whole grains, fruits, and vegetables.
• Yellow foods have more calories per ounce and include beans, low-fat cheeses, yogurt, and many low-fat types of meat.
• Red foods are the most calorie-dense and include red meat, juice, nuts, chocolate, and pizza.

Two weeks later, after starting the app, you will be assigned to a support group of other dieters along with a group coach.

These groups can be accessed 24/7, and the coaches check in daily and comment on your calorie intake for that day.

Though former Noom employees told Insider that coaches may be juggling hundreds of clients at a time and therefore cannot provide the individualized feedback a person may need to lose weight and keep it off.

Moreover, Noom coaches aren't necessarily registered dietitians but instead are trained through the company's "Noomiversity."

How the Noom diet came to be

The Noom app was created in 2008 by Saeju Jeong and Artem Petakov. According to the company website, the Noom diet was developed with an emphasis on psychology as much as nutrition.

It is not a prescribed diet in the sense that it doesn't restrict you to a certain type or amount of food. Rather it's a way to plan meals and change behavior with the support of a group.

Insider's takeaway

Noom may help some lose weight. However, its downsides are due to the fact that - at the end of the day - Noom is not a wellness company.

As Noom's chief psychologist told Insider in an e-mail, "Noom is a technology company." So, its bottom line is business, not improving your health.

So before you sign up it's important to do your homework:

• Check online reviews about subscription cancelations as there are complaints that Noom makes it difficult to cancel.
• Check online communities like Reddit for personal accounts of how helpful and personable their Noom coach was.
• Check reputable online weight-loss calculators like the Mayo Clinic's, to see how many calories you need per day to stay healthy while also remaining in a caloric-deficit for weight loss. Then cross-check that with the calorie restrictions that Noom recommends as reports indicate it can suggest an unhealthily low amount.

Lastly, Noom does not screen for a history of eating disorders. If you have a history of an eating disorder, Noom's color-coding food system may be triggering for you.

While Noom may be more financially appealing than hiring a registered dietitan, it's important to consider what you're getting for your money.