
Ask HN: How do I evaluate a scientific study? - cjw3
Recently I’ve been trying to base more of my decisions on published literature rather than secondary and tertiary sources, mostly in the area of health and diet. But apart from sample size, I don’t know where to start in evaluating the merits of a study. When comparing existing results to make a decision, what sort of factors should I consider? Experimental design? P-value and significance level?<p>It’s particularly an issue when so many issues have contradictory studies, and it’s hard to decipher which one is more likely to be correct!
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sethammons
Nobody knows anything and so many things are in dispute.

Listen to your body. Take up an exercise regiment.

Expanding: we've learned that excess sugar is likely really bad, and a bunch
of other stuff. Learn what you do good on. Spend some time doing vigorous
exercise (like, panting, sweating, want to lie down and stop type vigorous).
After you get used to that, do an elimination diet. Go to lean meats, eggs,
green veggies, and water only. Plenty of water. Do that for a few weeks.
Notice how your body feels while exercising. Then, spaced out (like a week
between each step), re-introduce other foods. Roots, nuts, legumes, dairy,
pasta, bread, etc. Try to avoid sugary stuff, but do re-introduce it like
everything else.

Most people find that different foods make them literally feel gross or bad,
especially during working out. You'll learn what makes you bloat or gain
weight. Find the things that don't fit for you, and just leave them mostly out
of your future menus.

Vitamins? Protien? Supplements? Same process. Introduce and listen to how you
feel. You'll then know more about you than any flawed study will.

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sn9
It generally takes biology students at the advanced undergrad to early grad
student level two years of weekly literature reviews with groups of their
peers and mentors where they discuss the merits and shortcomings of research
papers before they become able to reliably be able to do this on their
own.They start out spending several hours per paper to dive deep before taking
less than an hour (my professor took 30 minutes) when they're proficient.

For a layman to try to do the same without the same feedback mechanisms is an
exercise in futility that will almost certainly result in misunderstandings.
Most people online without that necessary background who claim to accurately
interpret research literature are fooling themselves and the people who
believe them.

If you want to have a more informed and evidence-based perspective on some
field, you should start with the resources that are tested on millions of
students every year, constructed in a coherent fashion to communicate the more
reliable findings of a field that are considered essentially true by
consensus: I am talking about textbooks, of course.

And if you can't be bothered to seriously read and learn the contents of
thousands of pages of textbooks, how much can you say you really want to
understand the context of research papers that assume that knowledge
implicitly?

If the above seems to be more work than you care to commit (a completely
reasonable conclusion!), just stick to some basic heuristics that seem to have
been held true for decades or longer and are consistent with the advice of
medical professionals over the ages.

Michael Pollan's advice to "Eat food. Mostly plants. Not too much." is pretty
solid.

If you want to go further, you could try to max out your RDAs for all your
micronutrients from a diet composed of whole foods by playing around on sites
like Cronometer.

For more evidence-based health recommendations centered around lifestyle
changes, the Barbell Medicine Youtube channel is pretty solid.

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ajaxaddicted
When you are looking at health related studies, look for the following magic
keywords: "Double-blind, placebo-controlled randomized study"\- ideally, not
funded by the meat, egg or diary industry. The more plant based whole organic
foods you eat, the better. If you don't feel in an optimal state - don't
guess, dont listen to "your body", dont follow random advice from people on
the internet - find people who a actually medical professionals and(or)
certified nutrionists. Do a blood, SIBO, gut microbiome tests to see where you
stand.

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jmnicholson
[https://www.statnews.com/2018/12/13/solving-fake-news-
proble...](https://www.statnews.com/2018/12/13/solving-fake-news-problem-
science/)

