Noom Review: Can a Phone App Cause Weight Loss?

Noom Review: Can a Phone App Cause Weight Loss?

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Noom is one of the most popular weight loss apps, and it provides a comprehensive approach to dieting. The brand describes itself as "an award-winning weight loss program," and it offers users the ability to connect with coaches virtually for personalized support and training.

But is Noom proven to cause weight loss in research studies? And if so, how much? What makes Noom different from other weight loss apps? And how do real Noom users rate and describe the effects of the program?

In this article we’ll answer all of these questions and more, as we analyze results from clinical trials on Noom to determine if the program is likely to be effective for weight loss, and if so, how much weight loss it causes.

We'll explain how Noom works, feature unsponsored customer reviews, and share our concerns with the brand's food lists and data security measures.

We'll also compare Noom to Weight Watchers, and explain why Noom was sued for over $50 million in 2022.

Is Noom Proven to Work?

Noom has been studied in clinical trials published in legitimate, peer-reviewed medical journals which is a good sign about the legitimacy of the brand.

A medical review published in the Scientific Reports journal tracked nearly 36,000 Noom users, and found that the app caused weight loss on average.

31% of users lost greater than 5% body weight, 24% of users lost 10% body weight and 4% of users lost greater than 20% body weight.

The median duration of app usage was 267 days, so the annualized figures are even higher. 

A 2021 clinical trial examined whether Noom is effective for postpartum (post-childbirth) weight loss. Postpartum weight retention is a common problem, and Noom was found to be effective in this patient population.

After 24 weeks, the women lost an average of 8.99 pounds, and 80% of Noom users lost weight.

A clinical trial published in the International Journal of Environmental Research and Public Health evaluated body positivity and self-compassion in a cohort of Noom users.

Since some individuals struggling with obesity have related concerns about self-image, this is an important consideration.

Not only did the trial participants lose weight while using Noom, but their self-reported scores of body appreciation, body image flexibility and self-compassion significantly improved. This suggests that the coaching aspect of Noom's service may provide additional benefits to mental health beyond weight loss.

Noom has a Research section of their website with citations from over 40 clinical trials on their weight loss program.

Based on the available research, we consider Noom to be effective for weight loss and potentially effective for supporting mental health improvements. We're impressed by the significant clinical research backing for this app.

As we highlighted in our does Noom work article, some medical experts have concerns over Noom's weight loss strategies, but overall we consider Noom to be a significantly superior option to most commercial weight loss programs.

Real People Try Noom

A YouTube creator named Nicki DeAngelo reviewed Noom and shared before-and-after images in a video with over 95,000 views:

A YouTube creator named "MikhilaTALKS" claims to have lost over 20 pounds using Noom:

Why Was Noom Sued?

In June of 2022, Noom settled a class-action lawsuit for $56 million, according to Top Class Actions.

According to the above-linked article, Noom was alleged to have made it challenging to cancel auto-renewal plans, by not clearly disclosing the auto-renewal terms, and by not providing a simple way for users to cancel online.

This settlement has closed, which means that any user believed to have been harmed by this practice cannot take part in this lawsuit. The settlement funds are already allocated.

This is a red flag in our opinion about the ethics of this company, although a settlement doesn't assume guilt, and Noom has not admitted to any wrongdoing.

Is Noom's Food List Unscientific?

Noom food list

Noom categorizes foods into "green," "yellow" and "red" foods by caloric density and healthiness. Some of the "red" foods are shown above.

"Green" foods have low caloric density and "red" foods have high caloric density and low nutrition, according to Noom's website.

From a weight loss standpoint, this approach is logical. Denser foods can lead to more calories consumed per meal.

However, from an overall health perspective, we consider this categorization slightly concerning because the subconscious effect of foods being categorized as "red" may disincentivize users from eating healthy "red" foods like nuts and seeds.

Nuts and seeds are incredibly healthy foods that are not only proven in medical research to be associated with reduced all-cause mortality, but also with reduced rate of biological aging.

We would not want to disincentivize individuals from eating this category of whole foods at all.

How Does Noom Work?

Noom's app provides health information and tracking features that help consumers make more informed nutrition choices.

The app also pairs users with a health coach that can help support their weight loss goals. This type of individualized encouragement and accountability can help users stay committed to consistent weight loss.

The app has weight logging, food logging, water logging and step counting trackers that provide updated metrics which can help users lose weight on a daily basis.

Noom provides healthy recipe options as well.

Below is a video from YouTube creator Laura Marschel who shows what the Noom app actually looks like and how it works:

Our Data Privacy Concerns

Health and biometric data is arguably the most personal data that exists, and it’s a significant responsibility for health-related startups like Noom to ensure this data is stored securely and is not shared unnecessarily with third parties.

Noom's Privacy Policy claims that user data can be shared with the following groups:

  1. "Other services"
  2. Service providers
  3. Financial services and payment processing
  4. Corporate transactions
  5. Legal and law enforcement
  6. Advertising providers
  7. Other groups required to "protect our customers and others"

We disagree with this practice on ethical grounds. We don't believe that companies gathering health data should share customer personal information with third parties, especially advertising providers.

At the time of updating this article, there's no information on Noom's Privacy Policy page about practices to anonymize or encrypt this sensitive data.

We urge Noom to stop the practice of sharing personal customer information with third parties, even if that means they need to charge slightly more per month to offset any potential revenue loss.

Noom vs. Weight Watchers

Since Weight Watchers (also referred to as "WW") is another popular weight loss program, consumers are often curious about which is likely to be more effective.

The good news is that both programs are proven in legitimate clinical trials to cause weight loss.

An extensive medical review published in 2016 examined the efficacy of various commercial weight loss programs including Weight Watchers and Noom.

The study authors found that individuals using the Weight Watchers program experienced 2.6% greater weight loss than a control group after 12 months.

The same medical review found that Noom caused more weight loss than Weight Watchers, as we documented in our Weight Watchers reviews article.

It's also notable that the results achieved in the clinical trials on Noom, highlighted in the first section of this article, were far superior to 2.6% greater weight loss than placebo.

Overall, we consider Noom more likely than Weight Watchers to cause weight loss.

How Much Does Noom Cost?

Noom has a variable pricing model.

Longer plans are cheaper per-month, and shorter plans are more expensive on a monthly basis.

At the time of updating this article, the price of a monthly Noom plan is $70, while an annual plan costs $209.

This means that the annual plan only costs $17.42 per month, which we consider to be quite reasonable given the research backing. This is cheaper than most gym memberships and most commercial diet programs.

For those who can afford it and who are committed to long-term weight loss, we would recommend the annual plan given that it's only 28% of the cost of the monthly plan, on a per-month basis.

Our Clean Weight Loss Picks

There are food-based nutrients which have been shown in medical studies to be effective for weight loss.

Dietary fiber was shown in a medical review published in The Journal of Nutrition to cause 16 pounds of weight loss in 6 months when combined with moderate caloric restriction (750 calories per day below baseline).

MBG Organic Fiber Potency+ is our top fiber pick because it's certified organic, provides 7 g of fiber per serving and costs under $1.85 per serving at the time of updating this article.

MCT oil was shown in a meta-study to cause more than one pound of weight loss over 10 weeks. This equates to potential annualized weight loss of 6 pounds per year with less than one tablespoon's worth of MCT oil per day.

Bulletproof MCT Oil is our top MCT oil product, because the only ingredient is MCT oil derived from coconuts. and it currently costs only $15.50 for over a month's worth of product.

Ginger intake "significantly decreased body weight" according to a 2019 meta-study on ginger and weight loss that analyzed data from 14 clinical trials.

Pique La Ginger is our top ginger product, because it's an organic tea in convenient crystallized form, and all that's needed is to pour the powder into a glass and add hot water.

All three of the products mentioned in this section are entirely free of additive ingredients that we consider to be unhealthy.

Pros and Cons of Noom

Here are the pros and cons of Noom in our opinion:


  • Clinically proven to work
  • Unlikely to cause side effects or health risks
  • More effective than most weight loss programs
  • Mostly positive online customer reviews
  • May benefit self-esteem of users
  • Affordably priced


  • Brand sued over alleged auto-renewal issues
  • Food color coding disincentivizes eating some healthy foods
  • Noom may sell customer data to advertisers
Stay up-to-date on our research reviews


Noom is effective for weight loss. It's one of the most well-studied weight loss programs in the US, and the average weight loss results achieved by Noom users are impressive.

This program seems to support long-term, sustainable weight loss, which is a good thing for users. Many weight loss programs that we've reviewed to date on Illuminate Health are effective short-term, but lack long-term research backing.

Noom was shown to cause greater weight loss than Weight Watchers in a medical review cited in this article.

In 2022, Noom settled a class-action lawsuit for over $50 million that alleged that the company made it challenging for users to cancel auto-renewal plans.

We disagree with the company's color coding of food, because it disincentivizes eating some healthy foods like nuts and seeds.

Noom has a large number of third parties that it may share customer data with, including advertisers. We consider this to be questionable from an ethical perspective, given that Noom collects sensitive customer health data.

The brand also fails to document whether sensitive data is anonymized or encrypted, in their Privacy Policy, at the time of updating this article.