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In the Instagram exchange that prompted this article, the account @ozzi__silva makes an unusually useful distinction.
He writes, in Portuguese, that he is not a scientist or an academic, and then points instead to his status as a prominent reference in Portuguese fitness.
That is not automatically a problem.
You do not need a PhD to explain a randomized controlled trial. You do not need a university position to be a good coach. An academic title does not guarantee clear reasoning, and the absence of one does not prevent someone from understanding evidence.
The interesting problem starts somewhere else.
Ozzi Silva's public brand is built explicitly around science.
He is publicly presented as the creator of Human – Greatness by Science. A Prozis profile describes the project as a science-based fitness and wellness coaching platform dealing with nutrition, sleep biology, physical performance, human behaviour and philosophy. Podcast appearances similarly frame his advice as grounded in current scientific evidence.
So the relevant question is not:
Is he a scientist?
It is:
What evidential standard should apply when “science-based” is the source of authority?
That question matters well beyond one Instagram account.
What the public brand actually does
The public footprint is broader than exercise programming.
A three-hour 2024 appearance on Conversas de Elite was organised around fitness and longevity, intermittent fasting, sleep and circadian rhythms, carnivore versus ketogenic versus plant-based diets, omega-3, multivitamins, vitamin D, creatine and neuroplasticity, hormonal optimisation through supplementation, testosterone, contraception and anabolic steroids.
A 2025 BMS Podcast appearance expanded into sleep, supplementation, circadian rhythms, mental health, anxiety, depression, carnivore diets, fasting and a proposed holistic role for fitness professionals.
In 2026, Conversas de Personal Trainers promoted an appearance under the title A Verdade Científica que Está a Desmontar o Fitness Moderno, describing Ozzi's approach as scientifically grounded and focused on separating knowledge from bad information.
This is no longer merely:
Here is how I programme squats.
It is a public communication model spanning exercise science, nutrition, cognition, endocrinology, mental health, longevity and supplements.
That breadth changes the evidential burden.
Sources:
Being a coach is not the problem
There is a weak criticism that should be discarded immediately:
He is not an academic, therefore he should not discuss science.
That is wrong.
Science is a method for generating and testing knowledge, not a protected language that only researchers may speak.
A skilled coach may know the applied literature in a narrow area extremely well. A researcher may know little about coaching practice. Good translation between research and practice is valuable.
The stronger criticism is almost the opposite.
If someone chooses science-based as the organising principle of a public identity, then scientific standards become relevant regardless of formal credentials.
At minimum, I would expect five things:
- Claims should be proportional to the strength of the evidence.
- Mechanistic plausibility should not be presented as demonstrated clinical benefit.
- Uncertainty and disagreement should remain visible.
- Expertise in one area should not silently transfer to unrelated areas.
- Commercial interests should be made obvious when products are discussed.
Those requirements do not depend on a university affiliation.
They depend on the word science.
A concrete example: the multivitamin post
The cleanest example is a public post hosted on Prozis under Human – Greatness by Science.
The post discusses whether multivitamins are useful, argues that modern foods do not provide the same nutritional quality as in the past, says the author personally uses an EVO multivitamin as a safety net, and states that the product ensures zero nutritional deficiencies.
The post then gives the discount code HUMAN.
This is useful because it allows us to separate four different questions:
They can coexist.
But they should not be collapsed into one another.
Source:
Claim 1: modern food has lost so much nutritional quality that a multivitamin is a sensible insurance policy
There is a genuine scientific literature on historical changes in crop composition.
Some modern high-yield crop varieties can show lower concentrations of particular minerals per unit weight. This is usually described as a dilution effect: yield increases faster than mineral accumulation.
That is a real phenomenon.
The stronger internet version is:
Food today is nutritionally depleted, therefore supplementation is broadly necessary.
That conclusion does not follow automatically.
A critical 2017 review of historical nutrient-composition claims found that comparisons across decades are confounded by changes in crop varieties, sampling, geographic origin, ripeness, analytical methods and databases. The review concluded that broad claims of progressive mineral depletion were not supported, although dilution effects in some high-yield varieties do occur.
Most importantly, even a measurable change in nutrient concentration does not tell us whether it creates a clinically meaningful deficiency.
Suppose nutrient concentration changes from $c_0$ to $c_1$.
The biologically relevant question is not merely
It is whether total intake falls below requirements after accounting for
A historical difference in one food is not a diagnosis of deficiency in one person.
Source:
Claim 2: one multivitamin can “ensure zero deficiencies”
This is a much stronger statement.
The NIH Office of Dietary Supplements notes that multivitamin/mineral products do not even have a standard composition. Manufacturers choose which nutrients to include and in what quantities.
Many multivitamins contain relatively small amounts of calcium, magnesium and potassium. Individual requirements also vary with diet, age, sex, pregnancy, disease, medication, absorption, genetics and other factors.
A tablet cannot logically guarantee the absence of every deficiency unless we already know:
- which nutrients the person consumes;
- which nutrients the product contains;
- the dose;
- bioavailability;
- absorption;
- requirements;
- losses;
- relevant laboratory or clinical status.
Formally, for nutrient $j$,
where $I$ represents bioavailable intake and $R_j$ represents the person's requirement.
A generic product does not observe all three terms.
So “ensures zero deficiencies” is not simply optimistic language. It is stronger than the information available can support.
The NIH does acknowledge that multivitamins can help people whose diets do not provide adequate nutrient intakes, and recent COSMOS substudies have reported modest cognitive benefits in older adults. That is precisely why the correct conclusion is not “multivitamins are useless”.
It is:
Benefits depend on population, baseline status, formulation and outcome.
That is a very different statement from a guarantee.
Sources:
- NIH Office of Dietary Supplements: Multivitamin/mineral supplements
- COSMOS multivitamin cognitive trial and meta-analysis
Claim 3: the evidence is divided, so both sides deserve similar weight
This is a common form of scientific rhetoric because it sounds balanced.
But science is not a debate programme.
Two positions do not deserve equal weight merely because both positions exist.
Evidence should be weighted according to study design, sample size, risk of bias, replication, effect size, confidence intervals, pre-registration, outcome choice and relevance to the population being discussed.
For prevention of cardiovascular disease and cancer in generally healthy adults, the U.S. Preventive Services Task Force concluded that evidence is insufficient to recommend multivitamins for or against those outcomes. It specifically recommends against beta-carotene and vitamin E for that preventive purpose.
That conclusion is not:
scientists are split 50/50.
It is:
the evidence does not establish a sufficiently certain net benefit for those outcomes.
Those statements are statistically and epistemically different.
Source:
The commercial layer matters
The Prozis profile is not merely an archive of independent educational writing.
It identifies Human – Greatness by Science as a science-based fitness and wellness coach, provides the discount code HUMAN, and advertises a 10% discount associated with that code.
That creates a material commercial relationship around supplement recommendations.
It does not prove that a recommendation is false.
It does not prove bad faith.
It does not tell us what the financial arrangement is.
But it does create a potential conflict of interest that a reader should know about when evaluating product claims.
This distinction matters:
Instead,
A systematic review published in BMJ Open found that conflicts of interest are often poorly reported in health communication on social media and that financial relationships with industry are common among health professionals using these platforms.
Again, that does not establish misconduct by any particular influencer.
It establishes why disclosure is part of good evidence communication.
Sources:
- Human – Greatness by Science, Prozis profile
- Akl et al., BMJ Open: conflict of interest in health communication on social media
“Science-based” can become a form of branding
There is an important difference between using science and using the idea of science.
Actual scientific reasoning is often frustratingly conditional:
In this population, under these assumptions, using this outcome, the estimated effect was $x$, with this uncertainty.
Online communication rewards something different:
Science says this works.
The second sentence is easier to remember, easier to film, easier to sell and easier to defend in a comment section.
It is also frequently less accurate.
The problem is not simplification itself. Every educator simplifies.
The problem begins when simplification deletes the exact information needed to know whether a claim generalises.
A useful distinction is
whereas
That second category can look very scientific while being difficult to falsify.
Scope creep is another warning sign
The public material around Ozzi moves across an unusually wide range of domains.
Fitness programming is one thing.
Nutrition is another.
Sleep biology is another.
Clinical mental health is another.
Hormonal optimisation is another.
Neuroplasticity is another.
Contraception and reproductive biology are another.
A podcast episode description even labels one segment “Creatina para Aumentar a Neuroplasticidade”.
That title illustrates the problem well.
There is research on creatine and cognitive performance. A 2024 meta-analysis of 16 randomized trials found small improvements in memory and some measures of attention and processing speed, while finding no significant benefit for overall cognition or executive function.
Another 2024 systematic review concluded that the theoretical case for broad cognitive benefits remains weak in non-stressed populations, although some subgroups may benefit.
Neither result is equivalent to the simple claim
“Neuroplasticity” is a biological concept describing changes in neural structure or function.
A better memory score is not automatically a direct measurement of neuroplasticity.
This is a recurrent problem in wellness communication: a plausible mechanism is used as a more impressive name for an observed outcome.
Sources:
Popularity is not validation
The Instagram exchange that triggered this article contains another useful idea: social standing in fitness is presented as a response to criticism.
Popularity matters in communication.
It demonstrates reach.
It may demonstrate that people find the content useful.
It may reflect practical coaching success.
But it is not validation of a scientific proposition.
Let
and
There is no general rule that
The variables may sometimes correlate. They may also be almost independent.
A systematic review in Social Science & Medicine found that social-media influencers can affect health attitudes and outcomes in both positive and negative directions. That influence is precisely why evidential standards matter.
The ability to persuade is not the same variable as the probability of being correct.
Source:
Scientists do not own science, but science has rules
This is the part of the discussion that often becomes unnecessarily tribal.
Academics can be wrong.
Peer review can fail.
Published results can be biased.
Consensus can change.
Industry-funded research can be valid.
An influencer can read a paper correctly.
A coach can make a better practical recommendation than a professor who has never coached anyone.
None of that removes the basic standards of inference.
If an account repeatedly invokes science, a reader should be able to ask:
| Question | What a strong answer looks like |
|---|---|
| What study supports this? | A direct citation rather than “studies show” |
| What population was studied? | Age, health status, training status and sample |
| What was actually measured? | Clinical outcome, biomarker, questionnaire or mechanism |
| How large was the effect? | Effect size and uncertainty, not just significance |
| Was the study randomized? | Clear distinction between association and intervention |
| Does evidence disagree? | Explanation of why studies differ |
| Is a product being sold? | Clear commercial disclosure |
| Is this outside the speaker's core field? | Appropriate caution or referral to specialist evidence |
That is what “science-based” should buy the audience.
Not certainty.
Auditability.
The deeper problem is asymmetric scepticism
A common pattern in online health communication is to apply very high scepticism to institutions and very low scepticism to one's preferred alternative.
A weak observational study supporting a fashionable supplement is called promising.
A large trial showing no effect is criticised for imperfect adherence.
A mechanistic paper is treated as sufficient when it supports the narrative.
A mechanistic objection is dismissed as insufficient when it does not.
This is asymmetric scepticism.
Formally, the decision rule becomes
That is not evidence-based reasoning.
It is motivated reasoning wearing scientific vocabulary.
I am not claiming that every Ozzi Silva post follows this pattern. That would require a systematic content analysis.
I am saying that any account built around Greatness by Science should be evaluated specifically for this failure mode.
What good influencer science could look like
The solution is not to remove influencers from health communication.
That would be both unrealistic and undesirable.
Good communicators can make evidence accessible to people who will never read a systematic review.
The World Health Organization explicitly recognises the importance of credible health information on social media and has developed principles for identifying reliable sources.
A strong fitness communicator can add enormous value by translating the literature while remaining clear about where the evidence ends.
The standard can be simple:
Be as precise about uncertainty as you are confident about the headline.
If a supplement may help a subgroup, say which subgroup.
If evidence is mixed, explain why.
If a mechanism is speculative, call it speculative.
If a product is commercially linked, make the relationship impossible to miss.
If a claim crosses from fitness into medicine, cognition, endocrinology or mental health, raise the evidential threshold rather than lowering it.
Source:
Conclusion
The interesting thing about Ozzi Silva is not that he is not an academic.
He says that himself.
The interesting thing is that his public authority is nevertheless constructed around the language of science.
That creates a perfectly reasonable bargain with the audience:
you may use science as authority, but the claims then have to remain answerable to scientific standards.
In the public material examined here, there are examples where the communication moves beyond what the evidence can justify.
A multivitamin cannot guarantee zero nutritional deficiencies without individual information.
Historical nutrient-density research does not establish that modern food broadly requires supplementation.
A commercial affiliation does not invalidate a recommendation, but it does make disclosure and evidential discipline more important.
And a cognitive effect is not automatically evidence of increased neuroplasticity.
None of these observations requires questioning motives.
They require only a distinction that should be obvious:
The difference is not a credential.
It is whether the audience can inspect the evidence, assumptions, uncertainty and incentives behind the claim.
References
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Conversas de Elite. Ozzi Silva aka Human: Fitness com Ciência, Masculinidade e Feminilidade Tóxica. 23 September 2024. https://podcasts.apple.com/pt/podcast/ozzi-silva-aka-human-fitness-com-ci%C3%AAncia-masculinidade/id1596992067?i=1000670406719
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BMS Podcast. **O Super Coach, Tempo e Dinheiro Mal Gasto, Humanos No Fundo do Poço e a Maldita Ancestralidade Ozzi**. 27 May 2025. https://podcasts.apple.com/pt/podcast/o-super-coach-tempo-e-dinheiro-mal-gasto-humanos-no/id1768149438?i=1000710048162&l=en-GB -
Conversas de Personal Trainers. Ozzi Silva: A Verdade Científica que Está a Desmontar o Fitness Moderno. 4 April 2026. https://podcasts.apple.com/pt/podcast/cpt-93-ozzi-silva-a-verdade-cient%C3%ADfica-que-est%C3%A1/id1489272184?i=1000759183554
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Human – Greatness by Science. Prozis profile. https://www.prozis.com/pt/pt/m/209197/human?OT=AFFPT1003
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Human – Greatness by Science. Multivitamínicos: Benefício ou Desperdício? https://www.prozis.com/pt/pt/m/209197/human/2650707?oti=PDP_SOCIAL
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NIH Office of Dietary Supplements. Multivitamin/mineral Supplements: Fact Sheet for Health Professionals. https://ods.od.nih.gov/factsheets/MVMS-HealthProfessional/
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U.S. Preventive Services Task Force. Vitamin, Mineral, and Multivitamin Supplementation to Prevent Cardiovascular Disease and Cancer. 2022. https://www.uspreventiveservicestaskforce.org/uspstf/recommendation/vitamin-supplementation-to-prevent-cvd-and-cancer-preventive-medication
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Marles RJ. Mineral nutrient composition of vegetables, fruits and grains: The context of reports of apparent historical declines. Journal of Food Composition and Analysis. 2017;56:93–103. https://www.sciencedirect.com/science/article/pii/S0889157516302113
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Vyas CM, et al. Effect of multivitamin-mineral supplementation versus placebo on cognitive function: COSMOS trial and meta-analysis. American Journal of Clinical Nutrition. 2024;119:692–701. https://pmc.ncbi.nlm.nih.gov/articles/PMC11103094/
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Xu C, et al. The effects of creatine supplementation on cognitive function in adults: a systematic review and meta-analysis. Frontiers in Nutrition. 2024. https://www.frontiersin.org/journals/nutrition/articles/10.3389/fnut.2024.1424972/full
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Creatine supplementation research fails to support the theoretical basis for an effect on cognition: Evidence from a systematic review. Behavioural Brain Research. 2024;466:114982. https://doi.org/10.1016/j.bbr.2024.114982
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Powell J, Pring T. The impact of social media influencers on health outcomes: Systematic review. Social Science & Medicine. 2024;340:116472. https://pubmed.ncbi.nlm.nih.gov/38070305/
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Akl EA, et al. Conflict of interest and funding in health communication on social media: a systematic review. BMJ Open. 2023;13:e072258. https://bmjopen.bmj.com/content/13/8/e072258.abstract
- World Health Organization. Global principles for identifying credible sources of health information on social media. https://www.who.int/teams/digital-health-and-innovation/digital-channels/global-principles-for-identifying-credible-sources-of-health-information-on-social-media
This article analyses public communication and publicly available commercial material. It does not assess Ozzi Silva's motives, private coaching, private life, or personal character. Commercial affiliation is discussed as a potential conflict of interest, not as evidence that a claim is false.
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Diogo Ribeiro (2026). When “Science-Based” Becomes a Brand: Ozzi Silva, Fitness Influencing and Scientific Authority. Faculty of Media Arts and Design, Technical University of Porto. https://diogoribeiro7.github.io/healthcare/when_science_based_becomes_a_brand_ozzi_silva/.
