How to fact-check a health trend in under a minute: 5 checks
Before you try a health trend, ask five things: does it name its sources, does it say how strong the evidence is, does it promise a cure, does it work with your doctor rather than against them, and is the person selling the fix in the same breath? If it fails two or more, be wary. And once you know what's worth doing, the evidence on habits is clear: specific if-then plans, patience (habits take about 66 days on average), and supportive, shame-free coaching help changes stick.
Health advice is everywhere: in your feed, in adverts, in the group chat. Some of it is excellent. A lot of it is half-true, out of date, or selling something. If you live with a long-term condition, it can be exhausting to sort through, and expensive when you get it wrong.
These are the 5 checks I use before I post anything on my page. They take less than a minute, and they'll help you spot weak advice fast.
The 5 checks
1. Does it name its sources?
Good health information tells you where it came from: a named study, a review, or a guideline from a body like NICE or the NHS. "Studies show" with no study named is a red flag. So is a source that turns out to be a test in mice or cells.
2. Does it tell you how strong the evidence is?
Not all research is equal. One small study is a starting point, not an answer. Honest advice tells you whether something is backed by many good trials, a few small ones, or just a theory.
3. Does it promise a cure?
Words like "cure", "reverse" or "heal" are a warning sign for long-term conditions. Diet and lifestyle can make a real difference to how you feel, but promises of a cure usually outrun the evidence.
4. Does it work with your doctor, not against them?
"What your doctor won't tell you" is a sales tactic. Good evidence is published openly. Advice that sets itself against medical care is one to walk away from.
5. Is the fix being sold in the same breath?
Ask who benefits. If the person warning you about a problem is also selling the supplement, test or programme that solves it, look harder at their evidence.
How to tell strong research from weak
Here's the rough ladder of evidence, from weakest to strongest:
| Type of evidence | What it is | How much weight to give it |
|---|---|---|
| Personal stories | "It worked for me" | Can't show whether something works, because we don't know what else changed |
| Lab and animal studies | Tests in cells or mice | Useful for ideas, but most don't translate to people |
| Observational studies | Following large groups over time | Shows links, not proof of cause |
| Randomised controlled trials | People randomly put into groups | Can show cause and effect |
| Systematic reviews | Combine all the good trials on a question | Usually the strongest evidence |
The number trick to watch for
Headlines love relative risk because it sounds dramatic. If a risk goes from 5 in 100 people to 6 in 100, that's a "20% increase", but in absolute terms it's 1 extra person in every 100. Both numbers are true. Whenever you see a percentage, ask: "out of how many?"
What has strong evidence for making changes stick
Knowing what works is only half the job. The other half is doing it. Here's what the research says about building habits that last.
| Change | What the research shows | Evidence |
|---|---|---|
| Making specific if-then plans | A meta-analysis of 94 studies found that plans like "If it's 1pm, then I'll add vegetables to lunch" made people noticeably more likely to reach their goals than simply intending to. | Strong |
| Giving habits time | In a study of 96 people, a new daily habit took a typical person about 66 days to feel automatic, ranging from 18 to 254 days. Missing a single day didn't stop the habit forming. | Good |
| Feeling supported and in charge of your choices | A meta-analysis of 184 data sets found that support for people's sense of choice and confidence was linked to better health behaviours and wellbeing. | Good |
| Leaving shame out of it | In a study of over 1,000 adults, stigmatising health messages were rated as less motivating than supportive ones. Guilt isn't a good fuel for change. | Good |
None of this is about willpower. It's about planning, patience and the right kind of support, which is exactly how I've built my coaching.
From good information to habits that last
I hold every post on my page to these 5 checks. In coaching, I go one step further: we turn the evidence that passes into small habits that fit your life.
Evidence you can trust
I do the research reading for you and tell you honestly how strong it is, so you stop wasting money and energy on hype.
If-then plans built around your day
We turn each goal into a specific plan tied to something you already do, which is the method with the strongest evidence.
Six months, not six weeks
Habits take time to settle, so my programme gives us time to build one at a time and adjust through flares and busy weeks.
No shame, ever
Missed a day? That's normal and it doesn't undo your progress. We look at what got in the way and adjust the plan.
My take
Living with psoriasis since 2019, I've seen how much confusing advice there is, and how easy it is to spend money on things that don't work. That's why every post I make names its sources and says how strong the evidence is, even when the honest answer is "not very".
But information alone rarely changes anything. What helps my clients is taking the evidence that passes these checks and turning it into small habits, with support, until they stick.
Frequently asked questions
How can I tell if health advice online is reliable?
Check whether it names its sources, says how strong the evidence is, avoids promising a cure, works with your doctor rather than against them, and isn't selling the fix in the same breath.
What is the strongest type of health evidence?
Systematic reviews and meta-analyses of randomised controlled trials, which combine all the good studies on a question. Clinical guidelines, such as NICE's, are built on these.
What's the difference between relative and absolute risk?
Relative risk compares groups ("20% higher"). Absolute risk tells you how many people are affected ("5 in 100 rising to 6 in 100"). Headlines often use relative risk because it sounds bigger.
How long does it take to form a habit?
In one study of 96 people, it took a typical person about 66 days for a new daily habit to feel automatic, with a range of 18 to 254 days. The 21-day rule is a myth.
Sources
- Gollwitzer PM, Sheeran P. Implementation intentions and goal achievement: a meta-analysis of effects and processes. Adv Exp Soc Psychol 2006;38:69-119.
- Lally P, van Jaarsveld CHM, Potts HWW, Wardle J. How are habits formed: modelling habit formation in the real world. Eur J Soc Psychol 2010;40:998-1009.
- Ng JYY, Ntoumanis N, Thøgersen-Ntoumani C, et al. Self-determination theory applied to health contexts: a meta-analysis. Perspect Psychol Sci 2012;7:325-340.
- Puhl RM, Peterson JL, Luedicke J. Fighting obesity or obese persons? Public perceptions of obesity-related health messages. Int J Obes 2013;37:774-782.
Follow @habitiahealth on Instagram for a new evidence check most days.
I'm Shivy, a certified Integrative Nutrition Health Coach (Institute for Integrative Nutrition, 2020). I have a degree in biology and a master's in environmental science, and I've lived with psoriasis since 2019. I read the research on food, sleep, stress and movement and turn it into small, realistic habits. More about me.
This article is education, not medical advice. Always follow the advice of your GP or medical team, and check with them before changing your diet or supplements.
