Noom is a subscription-based weight loss app that uses behavioral psychology to change how you think about food, rather than just telling you what to eat. It combines daily lessons, a color-coded food system, calorie tracking, and coaching to help you build habits that stick after the program ends. The core idea is that lasting weight loss comes from understanding why you eat, not just what you eat.
The Color-Coded Food System
Instead of banning foods or assigning points, Noom sorts everything you eat into three colors based on calorie density: the number of calories per gram. Green foods have fewer than 1 calorie per gram, yellow foods fall between 1 and 2.4, and orange foods (formerly called “red”) exceed 2.4 calories per gram. The logic is simple: foods with lower calorie density tend to contain more water, fiber, and protein, so they fill you up with fewer calories.
Green foods include fruits, vegetables, non-fat yogurt, grilled chicken, eggs, tofu, brown rice, and quinoa. Yellow covers things like avocado, black beans, hummus, pasta, low-fat yogurt, and whole-grain tortillas. Orange includes nuts, nut butters, oils, bacon, full-fat dairy, chips, cookies, and soda. No food is off-limits. The system just nudges you toward eating more green and less orange over time.
Some foods get bumped up or down a color based on nutritional context. Whole grains like brown rice and quinoa get moved down one level because of their fiber content. Non-fat dairy lands in green, low-fat in yellow, and whole-fat in orange. Diet sodas are labeled yellow despite having zero calories because of low satiety and high processing. Alcoholic beverages and regular sodas get pushed up a color to encourage moderation. These adjustments mean the system isn’t purely mathematical; it factors in how satisfying and nutritious a food actually is.
Daily Lessons and Behavioral Psychology
Each day, Noom delivers short lessons through the app that draw on principles from cognitive behavioral therapy and the Diabetes Prevention Program, a well-studied federal weight loss curriculum. The lessons cover topics like stimulus control (rearranging your environment so healthy choices are easier), portion control, problem solving around setbacks, stress reduction, recognizing social cues that lead to overeating, dealing with negative thinking patterns, and relapse prevention. Most commercial weight loss apps include almost none of these. One analysis found that strategies like problem solving appeared in only 3.3% of competing apps, while topics like stress reduction, relapse prevention, and managing negative thoughts appeared in 0%.
The curriculum is designed to be read in a few minutes per day, delivered in a conversational tone with quizzes and prompts. Over weeks and months, the lessons build on each other, moving from basic food awareness to deeper behavioral patterns. The goal is to help you recognize the triggers, emotions, and thought patterns behind your eating habits so you can interrupt them.
Coaching and Community Support
Noom pairs users with coaches who are trained through the company’s internal certification program, called Noomiversity. Coaches use motivational interviewing techniques during conversations, which means they ask open-ended questions to help you identify your own barriers and solutions rather than simply telling you what to do. A coach might ask something like “When was the last time you felt motivated? What has changed since then?” to help you find the root of a setback.
The base subscription includes access to Noom guides and interest-based group communities for support through in-app messaging. Individualized coaching sessions via phone or video chat are available for an additional fee. The app has also introduced an AI assistant called Welli that helps with food logging and answering quick questions between coaching sessions.
Tracking Tools in the App
The app includes a food database with barcode scanning for packaged items, available on both iOS and Android. You log meals, and each food automatically gets its color label so you can see the balance of your day at a glance. There’s also water tracking and a calorie budget that adjusts based on your starting weight, goal, and activity level.
This is where Noom differs most clearly from a program like Weight Watchers. WW assigns point values to foods based on macronutrients and gives you a daily budget to spend however you like, with certain “ZeroPoint” foods you can eat freely. Noom’s philosophy leans more toward teaching you to intuitively choose lower-calorie-density foods rather than counting and spending a daily currency. Both approaches work, but Noom bets that understanding calorie density as a concept will serve you better once you stop using the app.
Does It Actually Work?
A cross-sectional survey study of previous Noom users who had lost at least 10% of their body weight on the program found that 75% maintained at least 5% weight loss after one year. At the two-year mark, 64% still maintained that 5% loss. For the more ambitious benchmark of keeping off 10% of body weight, 49% of users held on at one year and 42% at two years.
These numbers are solid compared to general weight loss statistics, where most people regain a significant portion of lost weight within a year. A 5% loss is the threshold where health benefits like improved blood sugar, blood pressure, and cholesterol typically begin. That said, the study surveyed people who had already been successful on the program, so it reflects maintenance among motivated completers rather than everyone who ever downloaded the app.
Noom Med: The Medication Option
Noom now offers a separate program called Noom Med that pairs its behavioral tools with prescription weight loss medications. You complete an online health assessment, then connect with a licensed clinician who evaluates whether medication is appropriate for you. If prescribed, options can include GLP-1 medications like Wegovy and Zepbound, or oral medications like metformin, depending on eligibility. The program includes ongoing access to a clinician for medication management and refills alongside Noom’s standard coaching and habit-change curriculum. Noom Med costs extra on top of the base subscription.
What It Costs
Noom is subscription-based, with pricing that varies depending on the plan length you choose. The app typically offers a trial period, after which you select a monthly or multi-month plan. Longer commitments come with a lower monthly rate. Add-ons like personalized meal plans, custom workouts, a metabolism test kit, and one-on-one behavior change coaching each carry additional fees. Noom Med, with its clinical evaluation and medication access, is a separate higher-cost tier. Pricing can shift with promotions, so the exact numbers depend on when you sign up and which features you select.
How Noom Differs From Calorie Counting Alone
Plenty of free apps let you track calories. What Noom adds is the psychological layer: daily lessons that teach you to notice patterns in your eating, reframe negative self-talk after a slip-up, and redesign your environment so the path of least resistance leads to a healthier choice. The color system simplifies food decisions without requiring you to weigh portions or do mental math at every meal. Over time, the idea is that you internalize these principles well enough that you no longer need the app at all.
Whether that tradeoff is worth the subscription price depends on what’s held you back before. If you already understand nutrition and just need a tracker, a free app does the job. If you’ve lost weight before but always regain it, the behavioral curriculum is what sets Noom apart from simpler tools.