Nutrition is confusing for everyone, even doctors and people with scientific training. When i first
started researching healthy food many years ago i was confused too. a lot of contradictory messages,
fat is good, fat is bad, carbs make you fat, on and on and on. little by little, as i kept digging,
things started to make sense and now i have peace of mind when it comes to food. i realized there's
one idea that made all the difference. every time i encountered confusion, this idea cleared it up.
all these contradictions in nutrition, eggs are good, eggs are bad, it's the fat, no it's the sugar,
and we can always find smart people on both sides, so sure that they're right and so convinced that
the evidence is on their side. how can that be? scientific evidence comes in three bags. bag 1 is
lab experiments. feed something to a mouse or throw something on cells in a petri dish and see what
happens. bag 2 are population studies. look at what people eat and see if they get sick, basically.
bag 3 are clinical trials. find volunteers, split them randomly ask them to eat different
things and see what happens. no bag is perfect. if it was perfect we wouldn't need the other two
together the three bags give us a lot of important information. confusing messages in nutrition are
like a magic trick. i show you one bag while hiding the other two. if you don't know there
are three bags, if you think there's only one big bag of evidence, that's very convincing and very
confusing. he showed me the bag! when two people argue contradictory messages they're looking
at different bags. here's the truth and here's the bag! that's not the truth, my bag is the true bag! no,
my bag is the real bag! we have to look at all three bags, that's called totality of evidence
and when you do, two things can happen: they can give you the same answer, everybody's
happy. if they give you different answers, you need a tiebreaker. bag 1, lab experiments, has
less weight. bags 2 and 3 involve living breathing humans so they're stronger evidence
many things are seen in test tubes or mice that don't pan out in humans. candidate drugs, disease
mechanisms, etc. what about bags 2 and 3? bag 3 weighs more. clinical trials. because you have
more control over the experiment. knowing about the three bags is incredibly powerful. questions
that baffle millions of people, including doctors, are suddenly clear to you. it's like knowing how
a magic trick is done. you can't be fooled anymore. lectins: if we throw purified lectins on cells in a
test tube, it can harm their function. so maybe that means foods with a lot of lectins like beans are
poison? confusion. look at all three bags. people who eat more beans in clinical trials or population
studies have better health outcomes. also, cooking inactivates lectins. so the effect of raw, purified,
concentrated lectins on cells in a test tube can be toxic but the net effect of cooked beans in
living breathing humans is overwhelmingly positive. clarity. saturated fat: in some population studies
people eating less saturated fat still had high risk of heart disease. so maybe saturated fat
doesn't matter? maybe you can eat bacon and butter and lard all day long and it makes no difference?
confusion. look at all the evidence. when we replace saturated fat with unhealthy foods
like processed carbohydrates, the risk of heart disease stays high. in careful trials replacing
saturated fat with whole grains, vegetables, nuts and seeds, some oil, the risk comes down
clarity. gluten: throwing some gluten components on intestinal tissues in the lab can cause cellular
dysfunction. so maybe whole grains are poison? confusion. look at all the evidence. people who
eat diets rich in whole grains, whether it's in population studies or clinical trials,
have lower disease risk. about 2% of the population are gluten intolerant and those people
should avoid wheat, barley and rye. they can eat the other 10 or 15 whole grains. as for the other
98% of the population, they can and should include whole grains in their dietary pattern. clarity. it
goes on and on. some fats are problematic so maybe all fat is poison and low fat is the only way to
eat and olive oil causes heart disease. look at all the evidence. people who eat olive oil have lower
risk of cardiovascular disease. population studies or clinical trials. nobody needs olive oil in
their diet but if you eat some it's not going to cause heart disease and if it replaces worse fats
it's actually an upgrade. some types of carbs have unhealthy effects so maybe all carbs are poison?
look at all the evidence. refined carbohydrates in excess can be problematic
but whole carbohydrates are health promoting. so next time you hear something about food that
leaves you confused, a headline or a bold claim, ask yourself: are they showing me all the bags?
here's more on how to find scientific information and here's a more detailed look at saturated fat
how to make sense of contradictory messages. thanks for watching, be well