Noom and SlimFast are two very popular weight loss programs.

However, while both are often used by dieters hoping to shed extra weight, each program takes a very different approach.

This article reviews the pros and cons of Noom and SlimFast to see how they compare.

Basics mobile app with tools and resources to promote weight loss
offers support from a virtual team
no foods are off-limits
partial meal replacement program
provides shakes, bars, and smoothies
offers a mobile app with tools and resources
Menu options encourages foods with a low calorie density, such as fruits, vegetables, whole grains, legumes, and lean proteins provides shakes, smoothies, and snacks that suit several dietary patterns and health conditions
Cost $59 for an auto-recurring monthly membership
$199 for annual membership
1-week trial available
no membership fee
shakes: $1.25/serving
shake mixes: $0.45/serving
snacks: $1–$2/serving
Effectiveness may be effective for long-term, sustainable weight loss meal replacements may boost short-term weight loss
Benefits provides social support
creates a custom plan
not overly restrictive
easy and convenient
doesn’t eliminate any foods or food groups
options available for several dietary needs
Downsides entirely virtual
may be challenging for those who aren’t tech-savvy or have limited access to a smartphone or tablet
can be expensive
focuses on processed products
increased risk of weight regain
expensive long term
emphasizes calories rather than nutrients

Here’s a closer look at how each program works.


Noom is a mobile app that helps you modify your diet and lifestyle to promote sustainable weight loss and overall health.

It collects information about your medical history, lifestyle, and weight loss goals to create a custom plan tailored to your needs. Using the app, you can easily track your daily activities and log your food intake to hold yourself accountable and work toward your goals.

Plus, Noom provides access to a library of healthy recipes, along with your own support team, which consists of a goal specialist, group coach, and virtual support group.

Unlike other programs, Noom doesn’t require you to restrict or eliminate any foods from your diet. However, it promotes foods with a low calorie density, which means that they contain a low number of calories relative to their volume.


SlimFast provides a range of meal replacements and snacks to support weight loss.

This diet replaces two of your daily meals with SlimFast bars, shakes, or smoothies and gives you three snacks per day, which can either be a SlimFast product or any other low calorie snack.

It also requires you to eat one “sensible” meal per day, which should contain 500–600 calories.

To get started, download the SlimFast Together app on any smartphone or tablet. The app provides recipes, meal planning tools, educational resources, a shopping list generator, and tool to track your food intake and activity levels.

Here are the types of meals that you can expect to enjoy on each program.


Noom doesn’t provide any meals or snacks as part of its program. Instead, it suggests foods to include in your diet and provides a variety of recipes.

On the app, foods are categorized as green, yellow, or red based on their calorie density.

Green and yellow foods have a low calorie density and should comprise the majority of your diet. These foods include fruits, vegetables, legumes, whole grains, and lean proteins.

Red foods, which have a high calorie density, include chips, cookies, and chocolate. These items are also permitted — but only in moderation.


SlimFast offers a variety of meals and snacks, including bars, shakes, smoothies, snack cups, and fat bombs.

The company offers various plans, such as:

  • Original. The original plan from SlimFast includes products high in both protein and fiber.
  • Keto. These keto-friendly products are low in carbs and rich in healthy fats.
  • Advanced Nutrition. This plan includes meal replacement shakes and smoothie mixes that are high in protein and low in carbs.
  • Advanced Energy. The shakes in this plan contain as much caffeine as a cup of coffee.
  • Diabetic Weight Loss. These products are free of added sugar and specifically formulated for those with type 2 diabetes.

Here’s a price breakdown for Noom and SlimFast.


Noom is a subscription-based service that starts at $59 per month for an auto-recurring monthly membership.

You can also purchase an annual membership for $199, or around $16.58 per month.

Plus, Noom offers a cheap 1-week trial — which starts at just $0.50 — when you sign up.


SlimFast doesn’t have any subscription plans or membership fees.

The app is free to use, and the products that you purchase are the only expense for following the program.

SlimFast products are available at many retailers and range quite a bit in price. Premade shakes generally cost around $1.25 each, while shake mixes cost about $0.45 per serving. Other SlimFast snacks and products typically cost $1–$2 per serving.

If you consume 2 premade SlimFast shakes and 3 SlimFast snacks per day, you can expect to spend around $254 per month. This figure doesn’t include other groceries or meals.

While both programs may aid weight loss, Noom is focused on making dietary and lifestyle modifications for long-term weight management. Thus, it may be more effective than SlimFast.


Some research suggests that Noom is a good option for those seeking to lose weight.

In fact, a small 8-week study funded by Noom found that women who used digital coaching programs, including Noom, achieved greater weight loss and better emotional eating behaviors than those in a control group (1).

Similarly, a study in 35,921 people showed that nearly 78% of participants reported weight loss after using Noom for an average of 9 months (2).

Several of the program’s key principles may be responsible for these results.

For example, Noom focuses on dietary and lifestyle modifications to support sustainable weight loss. A 10-year study in 2,886 people associated long-term behavioral changes with improved weight loss maintenance (3).

Furthermore, Noom encourages foods with a low calorie density, which may decrease appetite and support weight loss (4, 5).


Studies note that meal replacement programs like SlimFast benefit short-term weight loss.

One 12-week study in 174 people showed that eating one low calorie meal replacement per day led to significant reductions in body weight, belly fat, and total body fat (6).

In a large review of 23 studies, weight loss programs that incorporated meal replacements led to greater weight loss over a 1-year period, compared with diets that didn’t include meal replacements (7).

Several older studies, one of whose lead authors was a member of the SlimFast Nutrition Institute, have also found that SlimFast may be effective for weight loss — and as effective as traditional, structured diet plans (8, 9, 10).

SlimFast products are also high in protein, which can help keep you feeling full and reduce levels of hormones that control hunger and appetite, such as ghrelin (11).

Here are some of the other benefits that each program has to offer.


Noom provides access to online groups and personal coaches, which may benefit those who prefer social support to help stay on track.

It also collects detailed information about your diet, lifestyle, medical history, goals, and preferences to create a plan tailored to your needs. This may make it a good option for people who haven’t previously achieved success with one-size-fits-all diets.

What’s more, Noom isn’t overly restrictive or difficult to follow. In fact, you can still enjoy many of your favorite treats and indulgences in moderation.


SlimFast is simple, straightforward, and easy to follow, requiring dieters to prepare just one meal per day on their own.

It’s also very convenient and saves time by providing meal replacements and snacks that are ready to enjoy without any preparation.

Like Noom, SlimFast doesn’t ban any ingredients. Instead, it lets you enjoy your favorite foods in moderation as part of your one “sensible meal” per day.

SlimFast also offers products tailored to several eating patterns, including low carb, keto, and diabetes-friendly diets.

Both programs have a few potential downsides to consider.


Although Noom offers social support from personal coaches and peers, it’s completely virtual. All communication occurs through the app’s messaging system.

While this limitation may be fine for many people, it isn’t ideal for those who prefer in-person or video consultations. It may also be challenging for those who aren’t as tech-savvy or have limited access to a smartphone or tablet.

Additionally, Noom can be relatively expensive, especially if you opt for a month-by-month membership.

Unlike other programs, the subscription fee only provides access to the app. Other expenses like food, cooking tools, and workout equipment aren’t included.


Rather than teaching you to make healthy dietary and lifestyle changes, SlimFast focuses on replacing meals and snacks with packaged products.

While this system may be convenient, it’s unsustainable in the long run and may increase your risk of weight regain once you transition back to a typical diet.

It may also get expensive over time, as the plan requires that you eat two SlimFast meal replacements per day, alongside multiple snacks.

Furthermore, while SlimFast doesn’t eliminate any food groups or ingredients, it focuses solely on calories rather than nutrients. As such, it may be challenging to build healthy habits, foster a positive relationship with food, and improve your overall diet quality.

For some people, the number of calories provided by SlimFast may be insufficient, which may lead to side effects like fatigue, nausea, and constipation (12).

Plus, inadequate calorie intake may increase your risk of nutritional deficiencies, especially if you rely solely on SlimFast products to meet your needs.

SlimFast may be a convenient, simple, and effective option for short-term weight loss. It may also help save you time by swapping several of your meals and snacks for premade SlimFast products.

However, it emphasizes meal replacements and calorie counting, which may not be as effective as dietary or lifestyle modifications for long-term, sustainable weight loss.

Noom, on the other hand, provides tools, resources, and support to help you reach your goals. While it has several drawbacks, it may be a better option for promoting weight loss and improving your health in the long run.

SlimFast is a program that uses prepackaged meal replacements and snacks to promote weight loss.

Meanwhile, Noom is a mobile app that offers tools and resources to help you make healthy changes to your diet and lifestyle.

Although both may aid weight loss, Noom is likely a better choice for long-term, sustainable weight loss.