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Both Noom and SlimFast are weight loss programs that promise to help people meet their weight goals.

While Noom is an app that focuses on long-term behavior changes, the SlimFast plan focuses on restricting diets through meal replacement shakes.

This article discusses the similarities and differences between Noom and SlimFast, alongside the health benefits and disadvantages of meal delivery.

Please note that the writer of this article has not tried these products. All information presented is purely research-based.

Below, we discuss the backgrounds of the Noom and SlimFast brands, alongside their reputation and reviews.


Noom logo over gray background

With Noom, a smartphone app encourages users to log their calories and replace high calorie foods with lower calorie options. It uses behavioral strategies to help people practice new habits.

Much of Noom’s marketing material focuses on the fact that users do not have to give up foods they love when following their plan.

Overall, the company have a positive reputation, with many nutrition experts stating that their services focus on overall health rather than stigmatizing some foods as “bad”. However, some diet skeptics emphasize that Noom can also encourage disordered eating or an obsessive focus on restricting certain foods.

All diets or weight loss plans may encourage disordered eating. Noom is not a plan that stigmatizes or labels foods “good” or “bad.” Their program allows people to adjust their diet through ways that are not focused on food restriction.

However, some Noom users have complained in online reviews about the company’s auto-billing practices. They also claim that the free trial is misleading.

Learn more about the Noom brand here.


Slimfast logo over gray background

SlimFast have been around for over 40 years. They began by providing meal replacement shakes but have now expanded to include snacks, protein powders, and other products.

SlimFast’s reputation in the health community is generally negative. Numerous blogs argue that it encourages unhealthy eating, eating disorders, and an unsustainable approach to weight loss.

Because the focus is on cutting calories, some reviewers say it does not teach dieters how to remain healthy over the long-term.

However, the SlimFast program remains popular as an accessible and simple plan.

Learn more about the SlimFast brand here.

The main difference between these two is that the Noom plan helps those who wish to maintain a moderate weight via an app, while the SlimFast program revolves around offering food and food replacement products.


A person can use Noom to suit any dietary preferences. They can even use the service alongside meal delivery programs or replacement programs, such as SlimFast.

Users enter their current and ideal body weight in the dedicated app. The Noom app then calculates their ideal daily energy intake, offering options for exercise, diet, and combinations to help people reach their weight goals.

Users can choose how quickly they want to progress, receiving daily tips for staying on track. They can also get help from a diet and health coach.

Noom offer their services as an app with a free trial. Users then pay a membership fee to continue with the program and receive regular coaching.

Noom is available for purchase online.


The SlimFast plan is a meal replacement program designed to decrease the number of calories a person consumes each day.

While the plan does not make specific exercise recommendations, individuals can increase weight loss with more exercise.

The SlimFast program includes:

  • One meal per day: Encourages one “sensible” meal per day, with a list of recommended recipes.
  • Two meal replacements: The SlimFast plan offers a range of meal replacement shakes that provide a range of nutrients, including vitamins and protein. Users on a specific diet, such as the keto diet, can choose shakes appropriate for those plans.
  • Three snacks: Participants also receive three SlimFast snacks per day. This includes a range of granola and meal replacement bars. They can also replace these bars with healthy snacks of a similar number of calories, such as dried fruit or a small serving of nuts.

SlimFast is available for purchase online.

Neither program forbids any specific food. However, SlimFast does restrict how many traditional meals a person can have per day.


Noom is the less restrictive program. Users can select their foods and then get input on how those foods fit into their overall goals.

The app also publishes a list of recipes, including user-submitted favorites, which fit into a person’s specific goals. Some examples include:

  • crispy sesame chicken with a sticky Asian sauce
  • bacon, egg, and kale breakfast salad
  • overnight oats
  • coconut energy balls
  • grilled romaine with cherry tomato salad


SlimFast’s more restrictive plan limits users to just one traditional meal per day. In addition to its shakes and meal replacement bars, some of its recipe options include:

The Noom service costs less per month — users subscribe for 6 months, usually for around $150.

However, because the program does not include food, the monthly menu cost may be higher, especially for users who focus on switching to fresh or whole foods.

Noom is available for purchase online.

The SlimFast plan is the more expensive option as it includes snack bars and shakes. A one-month supply of the food costs around $100.

SlimFast is available for purchase online.

Some alternatives to these two programs include:

There is some limited research into the effectiveness of Noom and SlimFast.


The evidence supporting Noom’s behavioral approach is fairly positive. A 2015 study found that users following the plan lost approximately 7.5% of their body weight over 15 weeks. They also maintained a weight loss of 5.2% from their body weight after a year.

A 2015 paper assessed the overall quality of weight loss apps rather than comparing their outcomes. It ranked Noom as the highest quality app, citing factors including the calorie calculator, behavior management strategies, and estimated calorie needs.

The 2015 research also found that Noom could improve fasting glucose in people with metabolic syndrome. A 2020 study of the service as a diabetes prevention tool found that it could help users keep weight off for at least a year. However, it did not observe a significant difference in average blood glucose levels.


The research supporting SlimFast is mixed, with a 2015 study finding little evidence of harm from the program. It also found no compelling evidence of sustained weight loss, particularly compared to behavioral programs such as Weight Watchers.

A 2006 study compared SlimFast to three other commercial diets, including Atkins, Weight Watchers, and Rosemary Conley’s Eat Yourself Slim. Participants in all four groups lost weight compared to controls.

However, some research also suggests that highly restrictive programs and meal replacement shakes may be a tool for dangerous weight loss for people with eating disorders.

There is no recent research directly tying SlimFast to better health outcomes.

Noom and SlimFast are both weight loss programs. Noom have an app that guides people in reaching weight goals by changing behaviors, while SlimFast offer meal replacement shakes and other products.

Reviews and research suggest that Noom may be more beneficial and healthy than SlimFast, although people will respond to the diet plans differently.

Those who are looking to maintain a moderate weight may wish to speak with a doctor and identify specific weight and health goals before choosing a weight loss program.