In my experience, you almost never find outright falsehoods in the health space. By and large, people are trying to help, trying to explain what worked for them or what they think is the best approach for a given problem.
What I do see quite a bit of, though, is lots of outdated, decontextualized or overblown information that has been modified for its ability to sell and be repeated.
Worthwhile and valuable information can come from anywhere, even meal prep Instagram. Good information can come from unlikely places, and even the things that seem like they’re too good to be true (hello, ketosis) may still have some interesting science behind them. In fact, I’d say there’s normally at least a kernel of truth in claims that get all the way into the mouth of someone like Doctor Oz.
A lot of it is not practically useful truth, though. It’s an interesting story about something that happened in some lab rats once, or a piece of advice that is appropriate in certain contexts but is now (incorrectly) taken as dogma.
So how do you know the difference? How do you separate the valuable from the interesting, the interesting from the useless, and the useless from the complete bullshit?
Simple. Ask critical questions.
What follows is what I do every time I make a claim, or hear a claim. It’s how I distill and validate information about health (and really anything) before I try it myself or share it with anyone.
Even though I’ve normally gone through this process for anything I write about, I encourage you to double-check my work if you’re curious or skeptical. As much as I would like to be, I’m not right all of the time. No one is. I’m still just some guy on the internet. I still make mistakes, and trust claims that I should have verified, and don’t read every piece of science that comes out. I think it’s valuable to be critical of all of the information you receive.
The process goes like this: ask questions, do some research if necessary, evaluate the answers, ask more questions. Not too groundbreaking. The effectiveness really comes from what questions you’re asking.
The five main question types I like are as follows:
- Questions of clarification — what specifically is the claim? What specifically is the purported benefit?
This puts you on level ground by letting you understand what you’re trying to evaluate as true or not. “Better” is not a specific claim, 15% better is. “University Studied”1in case you’re not familiar, this is a real example. It’s what USP Labs used to put on the label of their JACK3D preworkout doesn’t imply any outcome at all, even though it seems like it does. Many things that claim to improve an outcome or process don’t specify by how much, often because the answer to this question is “not enough to really matter.”
- Questions of origin — where did this claim start? What could be true about it?
Often, it’s beneficial to try and identify a kernel of truth in the claim and work backwards from there. Imagine how something you know to be true could be twisted into this claim, by starting with that kernel of truth and then expanding out from there, validating each new assumption along the way.
- Questions of evidence — what proof do they have that this is true?
This is the most obvious line of inquiry, but often the hardest to get to the bottom of. Generally speaking, peer-reviewed research is better than anecdotal evidence, but not always — high-level coaches often see things in their practice that are true but not yet rigorously studied or true for everyone. Even if there is research, it’s often hard to interrogate study design and breadth of evidence, even with good scientific literacy. Plus, when someone links to research, is it actually proving the thing they say it is? Or is it just a link to a research paper that has nothing to do with the actual claim?
- Questions that probe assumptions — what else must be true for this to be true?
An easy way to disqualify something as spurious is if it requires something you know to be clearly false to be true. A common one to look for is assertions that violate the laws of thermodynamics.
- Questions of intent — why are they trying to assert that this is true?
Understanding what someone is trying to get out of giving you this information can expose charlatans and bad actors quickly. Folks who are trying to sell you something based on that information (supplements) are less likely to be honest than folks that are trying to sell you information itself. Folks that are “just trying to get their ideas out there” or simply giving you advice (solicited or otherwise) are somewhere in between — sometimes their intentions are good but their information is wrong; sometimes they’re trying to sensationalize the truth for their benefit.
As a real-world example, let’s look at a classic piece of total nonsense, the idea that eating many small meals in a day “stokes the metabolic fire” and “increases your metabolism.”
I’m cheating a bit here because my base of knowledge is a bit larger than the average bear’s, but a quick google will confirm for you that this is a true but potentially meaningless statement — without getting into a very deep dive about metabolism, lots of things change your metabolic rate and your total daily energy expenditure, from your exercise intensity all the way to the ambient temperature.
Eating food certainly does increase your energy expenditure (it costs energy to convert food into usable energy in the body, called the Thermic Effect of Food, or TEF), but does how often you eat the food make a difference?
- Clarify: What does “increase your metabolism” mean? By how much? What is the value of increasing your metabolism?
When you hear this claim, you almost never get specific numbers to go along with it. This is generally a bad sign, because it reeks of a lack of evidence. Plus, it means this claim is hard to evaluate — if it does increase your metabolism, by how much? What specifically do they mean by “increasing your metabolism” or “stoke the fire”? Is it enough to be worth the practical hassle of preparing and carrying around a bunch of tupperware with small meals in it each day?
- Origin: Where could this claim have come from? Are there kernels of truth inside of it?
Two things that we know are true: many competitive bodybuilders eat six or more meals throughout the day, and there is an energy cost to digesting food, TEF.
Again, I’m cheating because I happen to already know this, but this is all information that can be had with a simple google (in fact, many claims can be confirmed or busted with a simple Google search — there is a cottage industry of blogs and companies like Examine.com who love gathering the evidence for and against this kind of stuff).
So then, we’ve expanded to three questions we need to look for evidence for: why do bodybuilders eat many small meals, how does TEF actually work, and does eating more frequently make it cost more energy somehow?
- Evidence: What can we find that supports (or does not support) this claim?
There’s no magic trick here. Just google it, and then know how to evaluate evidence. If there are links to scientific papers (or the evidence is itself a scientific paper), that’s good. If it’s anecdotal forum posts or Quora answers, that’s not necessarily wrong, but not a guaranteed fact either.
Google search one: eating six meals a day. You’ll find pretty quickly that there’s a lot of stuff about the exact myth we’re talking about (I picked an easy, well-trod one), but if you dig in a little bit, you realize that much of the actual recommendations being made by bodybuilders for bodybuilders is to eat six meals a day while bulking (that is, intentionally gaining weight), because for a 250 pound man on anabolics that’s trying to gain weight, it’s challenging to physically eat enough calories in just three meals. It has nothing to do with ‘the metabolic fire,’ it’s a simple matter of getting too full.
There are some additional recommendations to eat many small meals even when intentionally restricting calories to keep the body in an ‘anabolic’ (muscle building) state, but there’s not really ever evidence provided for this being very valuable, and it’s irrelevant to our question about metabolism. It’s a separate claim; to evaluate it, we’d have to start at the top again.
Google search two: the Thermic Effect of Food. Specifically, if the thermic effect of food is changed by how many meals you eat, or how frequently you eat, or something else. A good way to go about this search would be looking for how to measure TEF or how to estimate TEF. Most things that explain how to measure or estimate something necessarily break it up into its constituent meaningfully-impactful parts. We can also google directly for something like meal frequency thermic effect and find a scholarly article about exactly the question we’re asking.
Without getting into how to evaluate research methods and statistical data (I can do a deep dive on this in a future AMA if anyone’s curious, just shoot me an email): read the abstract and the conclusion or results section. It will normally give you your answer in plain-ish english.
Food seems to have a fixed thermic effect based on the food type and amount you eat, not how frequently you eat it. Many small meals would keep the metabolism constantly slightly elevated, but one huge meal would make it way higher and stay elevated for longer — but the total effect (the area under the curve) would ultimately be the same.
- We’re actually done at question three here, because there’s a decent amount of hard, relatively undisputed evidence about the claim. This will be true most of the time. Questions four and five are in a sense bonus questions, mostly only relevant if this isn’t the case — if the evidence is inconclusive, inconsistent, or there just isn’t that much of it, they can help to expand the questions to interrogate the question asker and the question itself.
What does this mean practically? Well, it means that there doesn’t seem to be much biologic advantage to eating a bunch of small meals instead of some number of larger ones.
From here, you can go down different, related lines of questioning to get the full picture of the claim. Are other reasons that one might want to eat many small meals in a day? Do they have evidence? Some potential ones you could look into:
- Blood sugar control (only really true/relevant if you’re diabetic, prediabetic or otherwise too metabolically inflexible to run on mostly fat for a period of time),
- Nutrient utilization somehow being superior when smaller meals are eaten (this is not how your digestive system works),
- There’s a maximum amount of protein you can utilize per meal (bunk, assuming you’re eating at least daily),
- Anabolism, including if anabolism is desirable or worth optimizing for (maybe; probably only if you’re a professional bodybuilder),
- Sports performance (actually some evidence being relevant, but it’s mostly about nutrition around actual training/competition, and striking a balance between fully-fueled and overfull),
- It helps with weight loss or appetite (If it feels good to you, go for it, but no conclusive evidence that I could find),
- And so-on. This can be a deep, deep rabbit hole if you want it to be.
Unsurprisingly, the real answer to “should I eat a bunch of small meals all the time?” is “it depends on what you’re optimizing for.” This is often the case for health and fitness-related things — few people are actively lying, but many people are repeating or implementing information without critically evaluating it first. Even if you have sources you trust, it’s still smart to do some of the work yourself.
PS: You’ll note that I only cite one source in this long practicum, which is much fewer citations than I normally provide. That’s intentional — I’m telling the truth here, but if you want to confirm that, you’re going to have to do your own research this time.
Enjoy your newfound skepticism.