What this page establishes
- A 2.5-year Noom Health RCT protocol has been published, indicating longer-term independent-format evidence is in progress.
- In a 12-week RCT of 105 participants using MyFitnessPal, weight change did not differ significantly by self-monitoring strategy (weight only, diet only, or both), with losses of 2.4-2.8 kg across arms.
- Consistent tracking (at least 6 days a week in at least 75% of weeks) was associated with greater weight loss than inconsistent tracking at 1, 3 and 6 months in a commercial app-based trial.
Quick answers
Which app produces the most weight loss?
The published between-group differences all sit in the same modest band, roughly 2-3 kg at three to six months.
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Tracking consistency predicts your result better than the choice between them does.Is Noom's evidence independent?
Mostly not. The largest trials are company-funded and announced by the company itself. That does not make them wrong.
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It does mean you should read the effect sizes in the trial rather than the framing in the press release, and note the 1.8-point in-program gap.Is MyFitnessPal enough on its own?
For self-directed people, often yes. It gives the most accurate intake picture of the three at no cost for the core features.
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It offers nothing to someone whose problem is motivation rather than information.
These three get compared as if they were competing versions of the same thing. They are not. Noom sells behaviour-change coaching with a psychology curriculum. WW sells a food scoring system with a community around it. MyFitnessPal sells nothing much at the free tier: it is a food database with a logging interface. The published outcomes land closer together than the products do, which tells you where the active ingredient sits.
Three mechanisms, one outcome
All three produce weight loss through calorie restriction. Noom routes you there through cognitive behavioural framing and colour-coded food categories. WW routes you there through a weighted points budget. MyFitnessPal routes you there by showing you a number and leaving you alone with it.
Self-monitoring is the shared active ingredient. Strip out the coaching, the community and the colour coding, and what remains in all three is a person recording what they eat and looking at the total. The trials support that reading. In a 12-week RCT of 105 MyFitnessPal users, weight change did not differ significantly by whether people tracked weight only, diet only, or both, with losses of 2.4-2.8 kg across arms.
The trial evidence side by side
The numbers below are the published between-group results. They sit inside a narrow band despite the products being priced and marketed as though they were different categories of intervention.
| Product | Best published result | Trial size and length | Independence |
|---|---|---|---|
| WeightWatchers | About 5.4% body weight at 6 months | 376 adults, BMI 27-45, digital program RCT | Peer-reviewed journal, company involvement typical for the field |
| Noom | 4.1% at 68 weeks vs 1.5% gain in controls; 1.2% loss vs 0.6% gain at the 16-week in-program mark | 427 adults, 16-week program plus 52-week follow-up | Company-funded and company-announced; a 2.5-year Noom Health RCT protocol is registered |
| MyFitnessPal | 2.4-2.8 kg over 12 weeks, no difference by tracking strategy | 105 participants, 12 weeks | Independent academic trial (JMIR mHealth) |
Noom: the psychology layer
Noom's differentiator is a daily curriculum drawing on cognitive behavioural techniques, plus messaging with a coach and a green-yellow-red food classification by energy density. The theory is that people fail on information-neutral tools because the barrier is behavioural rather than informational.
The evidence for the theory is mixed. Its own largest trial shows a small in-program difference and a larger gap at 68 weeks, which the company reads as durable behaviour change. That reading is plausible and it is also the reading with the strongest commercial value, so wait for the independent long-term data before treating it as settled. Adherence dropoff in this category is high.
WW: scoring plus community
Points has the longest trial record of the three and the widest clinical acceptance. Its edge is that the budget is simple enough to hold in your head, and its community layer gives some people a reason to keep going that an app alone does not.
Its weakness is cost relative to what you keep. Cancel the subscription and the Points values go with it, because the algorithm is proprietary. You keep the habits and the food knowledge, not the tool.
MyFitnessPal: a database, not a program
MyFitnessPal is the highest-ceiling and highest-effort option. Gram-level tracking gives you the most accurate picture of intake available outside a metabolic ward, and the free tier costs nothing.
There is no coaching layer, so it does the least for people who quit through loss of motivation rather than lack of information. The barcode scanner sits behind the paid tier now, which matters more than it sounds: scanning is the friction reduction that keeps people logging.
The database itself is crowdsourced, which is both why it covers almost every product on a supermarket shelf and why entries are sometimes wrong. Verify anything you eat weekly against the label once, and the error stops compounding.
Consistency is what predicts results with any of them. In a commercial app trial, logging at least six days a week in at least 75% of weeks was associated with greater weight loss at one, three and six months than inconsistent logging.
Cost, cancellation, and what you keep
Ask what remains when you stop paying. From MyFitnessPal you keep a habit and a rough sense of portion sizes. From WW you keep the same, minus the Points arithmetic. From Noom you keep whatever the curriculum taught you, which is the whole premise of the product and the hardest thing to verify.
None of the three has a mechanism to prevent regain once the subscription ends. That is not a flaw specific to apps. It is the same maintenance problem that follows every intervention on this site, medication included.
If you are on or coming off a GLP-1
On a GLP-1, the useful function of any of these is protein tracking rather than calorie capping. The deficit is handled. Missing your protein target is the risk, and only MyFitnessPal shows you grams of protein without arithmetic.
On the way off one, the calorie-capping function becomes the point again, and it becomes the point abruptly. Appetite returns before the habits are formed. A logging habit that is already running before the taper starts is worth more than which of the three you chose to run it in.
That argues for starting whichever tool you pick while the medication is still working, rather than after. The trial data on tracking consistency points the same way: people who log at least six days a week in at least 75% of weeks do better, and building that habit under low appetite pressure is easier than building it under high appetite pressure.
The evidence, one row per claim
| Claim | Tier | Source |
|---|---|---|
| Noom's largest RCT (427 adults, 16-week program plus 52-week follow-up, published 2026 in Obesity Science & Practice) reported 4.1% mean body weight loss at 68 weeks versus a 1.5% gain in controls, with 41% of Noom participants reaching at least 5% loss versus 19.5% of controls. | emerging | Noom (company release describing its own RCT — locate the journal article before citing as independent) |
| In the same Noom trial, the 16-week in-program difference was small: 1.2% loss in the Noom arm versus 0.6% gain in controls, a 1.8 percentage-point gap. | emerging | GlobeNewswire (Noom press release) |
| A 2.5-year Noom Health RCT protocol has been published, indicating longer-term independent-format evidence is in progress. | established | PubMed — Noom Health 2.5-year RCT protocol |
| In a 12-week RCT of 105 participants using MyFitnessPal, weight change did not differ significantly by self-monitoring strategy (weight only, diet only, or both), with losses of 2.4-2.8 kg across arms. | established | JMIR mHealth — comparing self-monitoring strategies RCT |
| Consistent tracking (at least 6 days a week in at least 75% of weeks) was associated with greater weight loss than inconsistent tracking at 1, 3 and 6 months in a commercial app-based trial. | established | J Behav Med — consistent self-monitoring in a commercial app intervention |
Questions people ask
Can I use one of these while taking a GLP-1?
Sources
- Noom (company release describing its own RCT — locate the journal article before citing as independent)
- GlobeNewswire (Noom press release)
- PubMed — Noom Health 2.5-year RCT protocol
- JMIR mHealth — comparing self-monitoring strategies RCT
- J Behav Med — consistent self-monitoring in a commercial app intervention
Keep reading
- WeightWatchers Points: How the System Works and What the Trials ShowPoints explained as calorie counting with deliberate distortions, plus the real trial numbers and the GLP-1 pi
- Energy Balance: The One Mechanism Behind Every Method on This SiteThe mechanism page. Every other page here is a different way of arriving at the same physiology.
- Adherence: The Variable That Beats Every MethodThe strategy page. Design the plan around the way you fail, because the method itself is close to interchangea
- Losing Weight Without a GLP-1: What Actually Works, By the NumbersEvery non-drug method ranked by published effect size in one table, with the 'natural alternative to Ozempic'