What is the best diet for humans? | Eran Segal | TEDxRuppin

What is the best diet for humans? | Eran Segal | TEDxRuppin

Translator: Rhonda Jacobs
Reviewer: Leonardo Silva This is me ten years ago. I weighed 40 pounds more than today, and like many people,
I wanted to lose weight. Like many people, I wanted to know
what is the best diet for humans. Many of us actually have an opinion
about this question. Some believe that a low fat,
plant-based diet is the best. Others, that a low-carb diet, rich in protein
and animal fat, is the best. Others have opinions
on how much sugar we should eat, or how much salt, cholesterol,
saturated fat, eggs or dairy products we should have in our diet. But the question of what the best diet is, is a scientific one, so there should be no room
for opinions or beliefs. If Diet A is really better than Diet B, then a study that compares
the two on enough people should show that definitively. No opinions, no beliefs,
just hard data, right? What is also clear is that
if the best diet does exist, then we haven’t yet found it because the incidence
of diet-related disease has increased dramatically
in the past several decades. Now, you might think it’s because
people don’t listen to what we tell them. But in fact, that’s not true, people actually generally
do follow dietary guidelines. But according to
the Center for Disease Control, if you live in the United States, there’s over a 70 percent chance
that you’re either overweight, diabetic or have non-alcoholic fatty-liver disease. And there’s overwhelming evidence
that diet and lifestyle are major drivers of these conditions. So why is it that after so much research, we still don’t have an answer
to the seemingly simple question of what is the best diet for humans? What I’d like to propose to you today
is that the reason we don’t have an answer is because we’ve been
asking the wrong question. And it’s the wrong question
because it assumes that the best diet depends
only on the food and not on the person eating it. But what if differences in our genetics,
lifestyle, our gut bacteria cause us to respond differently to food? What if these differences explain why
some diets work for some people but not for others? What if our nutrition needs to be
personally tailored to our unique make-up? This is exactly the question
we set out to ask in our own research, which I did with my colleague Eran Elinav and several graduate students
from the Weizmann Institute of Science. To take a scientific approach, we first searched for a metric
of healthy nutrition that we should study. Most studies examine weight loss
or risk of heart disease after some diet. But the problem is that these are affected
by many factors unrelated to diet, they take many weeks to change, and in the end, you get
a single measure of success. And if it didn’t work, well then
it’s very hard to understand why. And so instead, we searched for a metric that would still be relevant
for weight management and diet-related disease, but one that we could also easily
and accurately measure across many people. And this led us to focus
on blood glucose levels, and more precisely, changes
in blood glucose levels after a meal. We call this a “meal glucose response.” Why is it important? Well, because high
glucose levels after a meal promote both hunger and weight gain. After we eat, our body digests the carbohydrates
in the food into simple sugars and releases them into the bloodstream. From there, with the help of insulin, cells throughout our body
remove the glucose from the blood so that they can use it
as a source of energy. But insulin also signals our body
to convert excess sugar into fat and store it, and that’s a primary way
by which we gain weight. In addition, fast flow
of glucose into the blood often causes our body
to release too much insulin, which could lower our glucose levels
to below baseline, making us feel hungry and eat more. Meal glucose responses
are also very relevant for our health because they’ve been shown
to be risk factors for obesity, diabetes, cardiovascular disease
and other metabolic disorders. A recent study that followed
2,000 people for over 30 years found that higher meal
glucose levels after meals predict overall higher mortality. Finally, and not least important,
with recent technological advances, we can now follow a person’s
glucose levels continuously for an entire week. And since the average person
eats around 50 meals a week, it allows us to measure glucose responses
to 50 meals in just a single week. Meal glucose responses also provide us with a way to directly measure
the effect of every single meal, as opposed to common approaches that only evaluate
the effect of an overall diet. Now, of course, there are many factors
beyond glucose levels that influence a healthy diet. But this is a very important one, and solving it
can be a major step forward. Luckily for us, we managed to convince
1,000 healthy people of this idea, and we connected them
to one of these small glucose sensors and tracked their glucose levels
continuously for an entire week. And during that week, participants
logged everything that they ate on a mobile app that we developed. And so that allowed us
to measure glucose responses to 50 different meals for each person and around 50,000 different meals
across all 1,000 participants, making our study the largest one that was ever done
on this problem until today. So what did we find? Well, when we looked
at averages, we saw trends. For example, more
carbohydrates in the meal generally increase the response. This is not so surprising. Another, perhaps more surprising, trend is that more fat in the meal
generally decreased the response. But – and this is
the key finding of our study – for every trend we found, there were many people
who were very different from it. Basically, when the same person
ate the same meal on different days, the response was very similar. But when different people
ate the same meal, the response was very different. For example, white bread
induced almost no effect on the blood sugar levels of some people, but in others, it induced huge spikes. And the same was true
for every single food we tested, including rice, pizza,
sushi and even chocolate. For every food, there were some people
who had low responses, others who had medium responses, and yet others
that had very high responses. It wasn’t just about the food, it was also about the person eating it. So while averages
and trends are informative, for any given individual,
they may not mean much. Now, it wasn’t just about
how good the body was at handling sugar, each person had different foods
that spiked his levels. Some people even had opposite responses. For example, some people
spiked for ice cream but not for rice. But then others spiked for rice
and not for ice cream. In fact, more people spiked for rice
than for ice cream. Now, my wife is a clinical dietician, so when I showed her
this data, she was shocked, because as a practitioner, she of course
relies on general dietary guidelines, and so one of the first things that she tells her many
newly diagnosed pre-diabetics is to stop eating foods such as ice cream and instead eat more
complex carbohydrates such as brown rice. So, as soon as she saw our data, she of course realized
that for most of her patients not only does her dietary advice not help, but in fact, it pushes them faster
to develop the very same disease that her advice was meant to prevent. So these results of ours
on such a large data set convinced us that responses
to food are personal, and that diets that maintain
normal blood glucose levels must therefore be personally
tailored to the individual. They also show, in our view,
why the current nutritional paradigm that searches for that one best diet
is inherently flawed. The best diet for humans does not exist. Our responses to food are personal, so our dietary advice
must also be personal. And personalized dietary advice
was our next challenge. To tackle it, we measured
many parameters across participants that we thought may explain
people’s variability in glucose response to meals. And these included basic metrics
and lifestyle factors like age, weight, height and physical activity, but also blood tests, medical background
and food frequency questionnaires, and also DNA sequencing
of both the human genome and the gut bacteria composition
of each person. Now, of these, the gut bacteria was perhaps the most novel
component that we examined. For hundred of years, we know
that bacteria live within our body. But only with recent advances
in DNA sequencing could we begin to study them extensively. And when we did,
we found that this vast collection of hundreds of different species
that we each host, collectively termed “our microbiome,” has a major impact
on our health and disease. And what makes the microbiome
even more exciting is that unlike our genetics,
we can also change it even by simple means,
such as changing what we eat. Our bacteria help us digest
some of the food that we eat, and in turn, produce molecules
that are taken by our own cells and affect our physiology. For example, in our own research,
we studied artificial sweeteners, which the vast majority of us
consume on a daily basis in various diet soda drinks
and other products. And we found that consumption
of artificial sweeteners alters the composition of the gut bacteria
such that when transferred into mice causes the mice
to develop symptoms of diabetes. And so this and several other studies led us to ask whether the microbiome
would also be important for explaining people’s
glucose variability in response to meals. And so we took this microbiome
and other clinical data that we collected, and we used advanced
machine learning algorithms to automatically search for rules that predict personalized
glucose responses to meals. For example, one such rule could be that if you’re over 50,
and you have a certain bacterial species, then your response
to a banana will be high. The overall algorithm
combined tens of thousands of such rules that it automatically
deduced from the data. This approach is actually similar to how websites like Amazon
make book recommendations, except that we applied it
to how people respond to food. And we could show that this algorithm
could then take any person, even people who are not part
of our original study, and predict the response
to arbitrary meals with high accuracy. So as a final step, we asked
whether we can also use this algorithm to design personalized diets
that normalize blood glucose levels. So we recruited
and profiled new participants, and we asked the algorithm to predict
two diets for each person; in one diet, which we called
the “bad diet,” we asked the algorithm to predict foods for which that person
would have high responses. And in the other – “good diet” – we asked it to predict foods for which
that person would have low responses. And each person then followed
each diet for one week. Now, by design, the diets
had to be identical in calories. In fact, all breakfasts,
lunches and dinners had the same calories on different days. And it’s also important to note that each person received
a different personalized diet, and there were even some foods that were given to some people
on their good diet but to others on their bad diet. Now, to show you that these diets are not the obvious ones
you might think of, here they are for one of our participants. Now, take a moment and see
if you can guess for yourself which one the algorithm
predicted to be the good diet and which to be the bad diet
for this particular participant. And as you look at these,
notice that each diet contains foods that would not typically appear
in standard diets. And now for fun,
let’s play a quick guessing game, and you all have to participate. So, raise your hand if you think
the diet on the right is the good one. Okay. Now raise your hand if you think
the diet on the left is the good one. Okay, definitely we see
nearly a 50/50 split here, showing you that
it’s definitely not trivial to guess. And I can tell you
that for this participant, the algorithm predicted
the diet on the right, the one with the ice cream,
to be the good one. And so now the only question is
how good did these diets work. And what I’ll show you next is in our view perhaps the most striking result
that came out of our study. So here are the continuous glucose levels of this participant
when following the bad diet. And you can clearly see abnormally high
glucose levels after meals indicating that this participant
has impaired glucose tolerance and is likely pre-diabetic. But on the good diet,
the one with the ice cream and the same amount of calories
as the bad diet, this same pre-diabetic participant
achieved fully normal blood glucose levels without even a single spike
across the entire week. Obviously, we were very happy
to find out these results, and, in fact, we found similar results
for most participants for which we designed personalized diets
using our algorithm. Now, not only that, but the good diet
also induced several consistent changes in the gut bacteria of most participants. And it seemed that
these changes were beneficial, because bacteria that in other studies
were associated with good outcomes tended to increase after the good diet, and bacteria associated with disease
tended to decrease. And this result is of course
very intriguing because it suggests that in addition
to normalizing blood glucose levels during the intervention week, the good diet also induced
beneficial effects that may persist even beyond
the intervention week. So what’s the take-home message
from all of this? Well, based on the glucose
responses variability that we saw across 1,000 people, our conclusion is that
there is no single best diet for humans because we are all too different. It also means that if
a certain diet hasn’t worked for you, then maybe it was the wrong diet for you. Your dietary failures
may not be your fault. Your diet may have failed simply because it did not take information
about you as an individual into account. So what can you do
with this information now? Well, right now, you can actually measure your personal glucose responses
to your favorite meals using simple glucose devices
that you can buy at your local drug store. And I guarantee that you’ll be surprised at which foods personally spike
your glucose levels and which do not. As a more complete solution, we are working hard to make
our algorithms available to everyone so that you’ll be able, from your home, to provide basic
clinical information about yourself, send a sample of your microbiome, and in return receive
personalized dietary advice. We are also starting longer-term
dietary intervention studies in both pre-diabetics and diabetics
that will go on for a full year. Because we believe that if the effect
of normalizing blood glucose levels that we were able to obtain in one week
could persist for a longer time period, then we might be able to reverse,
and even cure, these conditions, which constitute one
of the worst epidemics of our times. More broadly, I believe that we are entering
a new era in the study of nutrition, one in which we will move away from asking
what is the best diet for humans, and instead, focus
on the more appropriate question of what is the best diet for me. Thank you very much. (Applause)

100 thoughts on “What is the best diet for humans? | Eran Segal | TEDxRuppin

  1. humans shouldn`t have lost the rumen organ ( now what is left of it is the appendix, for not been used it atrophied ) maybe we would be stronger and fewer diseases , what I mean if we stayed ruminants as our ancestors in the beginnings of our civilization

  2. Wrong. It's about food sensitivities and allergies. I am strict Carnivore. I get an inflammatory defensive response to almost all foods. Many people have had miraculous healing of auto-immune diseases and even problems like depression and anxiety that were completely unexpected to heal by changing to beef diet. I am even sensitive to chicken, eggs, dairy, lamb and pork. With one blood test for food allergies you can answer the question he asked in his most complicated study.

  3. We can learn much from our elders. My grandfather is 90 years old and still going strong. I just eat whatever he eats lol
    And since im healthy, strong and never get sick im pretty sure im doing it right.

  4. There's no such a thing as a good diet. Ebb and flow is the only real thing. This is utopia at its best. Moderation and excess will always coexist!. There are no easy shortcuts at all!

  5. As an internist, I agree with what he says, a perfect diet doesn't exist, nor will ever exist, our genetics play a significant role, a no 2 person react to food alike. Therefore an indivusual diet although not practical at the current modern era, hopefully is the answer in the future.

    Lastly for time being, since the science still has no answer for the best diet,
    I highly recommend giving intermittant fasting lifestyle a try. For sure it's not for everyone, but at the current era it's the most suitable for the masses to try.

    I myself use IF, and the results are staggering to say the least, from pre-diabetic hba1c 5.8%, to a normal non-diabetic person with hba1c 4.8%.
    More energy, less fatigue, lost weight BMI from 29.5, to 24 for now.

    It's my antidote to sickness.

  6. If blood glucose-response is the parameter, and fats have a NEGATIVE effect on blood glucose, why doesn't he put more emphasis on it??
    "Eating fats is the most healthy, but lets focus on whether rice or ice cream is less bad for you."

  7. It's wise, over the long haul, to improve one's diet incrementally, by choosing more healthy foods, such a better quality oils. Sugar has to be minimized, along with hard to digest foods. If you eat mostly junk food, you do have to make major changes. Now, I'm going to state something that will sound absolutely insane, but I have support for this statement, and welcome your inquiry or criticism.
    Chew for energy, chew for a smaller stomach.
    To get a handle on this crazy sounding statement, Google search the 'hunger hormones'. I can unpack these cryptic statements to give you powerful leverage on how to control your weight. This is, basically, an approach to weight control from the digestive angle. I can give you the easiest way to lose weight and keep it off. I lost 50 lbs in one year and have kept it off, now, for 5 years.

  8. All these years of looking at epidemiological data, at (often conflicted) experiments, it' all like trying to extrapolate the beauty of The Milk Way by looking at stars.

    Every animal evolved to eat certain foods and food types. Horses don't eat meat. Tigers don't eat grass. Yes, we are omnivores, but humans everywhere through all time want fatty meat as most desired. It's why meat on the grill gets us hungry, tofu does not. And proof that meat, most specifically cooked meat, was our ticket getting bigger brains because we did not waste energy supporting a huge plant digesting belly.

    Plant foods got us through times of bad hunting and allowed women and children to contribute to the tribe's pantry.

    Meat is digested entirely w/i the small intestine. Compare this to plant foods that need further bacterial digestion in the colon, often leading to IBS and other colon diseases.

    Eat primarily animal products. I've yet to see anecdotally, including YT, of anyone doing all meat or all animal products and finding problems with it. As Dr. Shawn Baker's site says, "Meat heals." The afflictions people have had for decades that went away going carnivore is huge. Conditions untreatable.

    Back to basics, eat animal products. It's what you evolved to eat.

  9. People keep asking WHAT to eat the real question is WHEN to eat. I reversed my step dads type 2 diabetes with a ketogenic diet paired with a fasting routine. In 2 months no lore diabetes and to this day he has no problems

  10. Idiots. They would have had to test the person after the bad diet because their microbiom would have changed after the bad diet

  11. "The best diet for humans does not exist" Eran says in this talk. I've known that for decades. Everyone is different. Everyone reacts to different foods in their own way. That's why it's so difficult to pin down the best personal diet and why, with some of us, it takes so long for us to get it right.

  12. I think it's better to ask, what type of diet do our MICROBES prefer since it's they that sweat away to digest and break down our food! We know that microbes our adaptable, but what do they prefer?
    It seems that most beneficial bacteria that live in our mouth, sesophagus, stomach and digestive tract are anaerobic. So we have plenty of Lactic Acid Bacteria. These bacteria prefer a slightly acidic environment.

    We know that human blood should be slightly Alkaline (Ph around 7.35), however 'we dont eat for our blood', since our blood dont digest our food – we eat for our microbes in our digestive system. Let's think about it for a second….Beneficial microbes in our Digestive tract prefers a slight acidic environment (below ph 7 )which helps to keep bad bacteria at bay.

    Fruits & vegetables and fermented foods Are MORE acidic when RAW and in their natural state. When Raw are cooked, acids are broken down during the heating process, rendering it more alkaline …. However interestingly, after these foods are digested by our microbes and energy is produced by our cells, they waste products have more of an acidic effect on blood ph, compared to raw fruits and vegetables.

  13. Insects, fish, shoots, leafy greens, fruits (seasonally) and rhizomes. Stick yourself in the wild and you’ll figure out the answer. We would regress same as domesticated pigs do back into wild boars.

  14. It's based of your genetics and every person should have a different diet. Obivously some people will have the same diet. Some scientists say look at your ancestors 500 years back or so and look at basically what they ate. Like if they ate more meat or veggies.

  15. Type II Diabetes is unequivocally due to sugar, ie carbs. The epidemic of obesity and diabetes can categorically be shown to be caused by carbs and the insulin spike they cause. That should be a clue!

  16. We need to understand one thing that we all are humans and we are not made to measure the insulin spikes in our blood or the protein carbs or fats requirements of our body…we are made to work hard physically to gather our food from nature and eat it…this is perhaps the best way to stay fit by far…and will remain always

    Now some people like this guy and many others are making this one line simple formula so complex that it feels like a far fetched dream to stay fit, which clearly is not the case…

  17. Lost a ton of weight few years back by eating the same food but MUCH less of it. Kept everything between 1600-1800 on sedentary days and 2200-2400 on high active days and was able to lose 65 pounds in eight months. Not saying this is the best but it worked.

  18. Excellent presentation and phenomenal research. Did you start with a hypothesis, or were you testing for other purposes?

  19. I am very happy to learn of this research – I am 61yo and according to my Oral Glucose Tolerance Test results I have Impaired Glucose Tolerance like the person in your example. I have been logging responses to meals with a Continuous Glucose Meter for a couple of months now and have been surprised by several of my responses which I would not have predicted using the Glycemic Index or Load. I believe that an analysis of the microbiome is the missing link in my quest. I should also note that I have achieved to maintain my glucose in a healthy tight range of values by time-restricted-feeding and postprandial exercise so it may be that I have not yet achieved the level of control that the person in your example achieved with more frequent and unrestricted meals.

  20. The reason for variations in people's insulin response is due to the Particular individual's activity Doing the day or lack of it' And their level of energy reserves in the form of glycogen in the liver or the muscle. It is not due to any other reason other than that.

  21. They tested white bread, (white) rice,pizza, sushi, chocolate, ice cream, foods with addend sugar but these are all junk foods. Why didn't they test whole unprocessed plant foods? Everyone I know who eats these are slender and thriving. Unless you have a particular food allergy, a whole, unprocessed plant food diet works well universally. Also, such a short-term study, one week, testing just one parameter is insufficient to determine such sweeping results.

  22. Once your pancreas slows or stops producing insulin, I don't think it can "be cured." Maybe I misunderstand the prof at 18:30. Gut bacteria and microbes are all the rage now. Maybe for good reasons.

  23. Vegan, but we manuka honey, and cbd oil! Works for me, no meat or dairy! Plus, just 1 meal a day, no breakfast, 1 meal at 12, and if you, want to lose weight, 1 drink, and 1 meal, a day!

  24. Well, eat boiled cold potatoes and that will restore your bacteria, as such that will restore you health topics. No one who was poor has been overweight and humanity has eaten starch menus for more than 1000 years……………………

  25. What did Adam and Eve eat? That's the best diet. Pick from the plants and eat it fresh, unprocessed, not even heated. Cooking kills the life elements, and live plant elements add life to us. But it's not quite that simple. Our soil is not the same as Eden soil, the minerals in our soil are usually very low, and out of balance. What's not in the soil the plants cant get. Poor nutrition built in, and poor health results. So we have to figure out how to remedy that. The revolution in agriculture being called nutrient dense or high brix methods are heading that way. Get it right and the flavor goes way up, appealing to the appetite. The production goes way up, appealing to the wallet. The "bad" bugs no longer like to eat it, which eliminates use of toxic insecticides. (chemical companies do not like that) byproduct of excellent flavor is increased demand, with drives up prices, more wallet joy to the farmer.

  26. The human digestive system is universal, hence there must be an ideal diet for humans. However, in individual cases, some modification is needed to make the diet work for that individual. In other words, there is a universal good diet for humans, but it may apply differently among individuals.

  27. quit about halfway through. didn't seem like that interesting a point. in my experience the best diet is the masai diet. the masai only live on foods from cows–milk, cream, beef, and they also extract blood from the cows and drink it without killing the cows.
    they do have one rule about food mixing–"if a man eats meat and drinks milk on the same day, he is a glutton"
    for me I've lived about 14 years 90% on cow milk and cow cream–wonderful diet.

  28. why was there no mention of race, or more specifically nationality or region that your ancestors have lived and fed for thousands of years? i'm sure Asians would process rice differently than Europeans…

  29. He hypes up the algorithm and then it produces a recommendation diet of sugar, soy & dairy… Come on man you're supposed to be a scientist.


  31. We do know the ideal diet, many of us just don't want to accept and implement it. It's staring at us in plain sight. Which 'diet doctors' are lean and trim? It's obvious. Forget glucose spikes and other complex metadata and saying that everybody is different, because we're not and it's not that complicated. I know of only one diet that has been proven to reverse heart disease, diabetes, cancer, etc., and the people who promote it are all slim and in good health.

  32. Just try every food, whenever that food increases your appetite (higher blood glucose level), stop eating it, period.

  33. At the end you say that eating ones correct diet can alter gut bacteria. So, can one eat to alter gut bacteria? For example, can a person eat certain foods to adjust their gut bacteria for a specific type of diet?

  34. What does seem to work for everyone is intermittent fasting. It can take a long time but eventually your body levels itself out to a normal weight.

  35. I have one question listening to this study…Yes, people have different levels of sugar in the blood eating the same food. But do these participants have the same level of insulin resistance, how much insulin has been discreet from pancreas??! Again, your study and algorithm are based on sugar level, which is not the right approach, imo. Lack of bigger picture I think…

  36. Awesome! This research can make a huge difference. Isn’t Ayurveda proposing different diets for different body types? Maybe ancient cultures already had an intuition on this topic.

  37. It would be interesting to compare the results between participants eating a whole goods, plant based diet. No one would get any ice cream for example but would anyone feel worse?

  38. this was an aweful talk- he said that there is no one diet to lose weight-it’s all individually based, but he did not give a solution -for example how I could figure out which would be the best diet for me. so badi ally he destroyed the hope of weightless through any diet without giving any pointers as to what to do to lose the weight.🤷🏼‍♀️

  39. Wrong…eat according to season and Environment without overthi king💥💥💥☝🏽 .no answers because food lobbyist push unhealthy REfined foods $$$$$$$$

  40. If weight loss is the goal of the diet, then it's not about the quality of the food that matters, but rather how much food and drink you consume and of course the energy balance equation. If you put less in then weight loss is automatic, and the body then achieves an improved insulin sensitivity. The microbiome sciences is so new that it is still guesswork as to whether it makes a real long term difference. Just eat less and move more, that will always work.

  41. OMG it was never focused by any of the dietician till date…You are so shocking, but you are confusing us more with these findings. Now the concept of the best diet for each of us is very complex…..

  42. Ice cream is a bad example. Plus, you didn’t say what kind. Not all ice creams are created equal. Substitute doughnuts, the ones with those wonderful cream fillings, then run your numbers and see what you get.

  43. sooooo…..hoping that one day…..a dietician or nutritionalist will simply be the GO TO person for our healths and they will be able to "prescribe" the proper diet specifically for you…of course…one of the things this guy failed to mention or if he did he did so in a subtle way….I do think, that you may find the "right" diet for yourself, but as you get older or simply change, that could very easily effect how you process food again….so it would be a continually monitoring of how your body works……until you drop dead….then again, if you are on a "diet" that is proper for you, perhaps dropping dead will not occur as often…: D

  44. "the question about what the best diet is is a scientific one, so there should be no room for opinions and beliefs". No, no and no.

  45. Brilliant and fascinating. Thank you for posting this. I'm really happy to have seen it and look forward to this information getting out into the medical community.

  46. From my experience, I had saw more meat eaters on a carnivorous diet more fitter and manly than vegans. Just my experience, your might be more different.

  47. So it comes to exactly what Dr. Bruce Lipton has discovered a few years ago: it is not the genes (or like here the foods), but YOUR BELIEFS. Our beliefs create our body and reality.

  48. I would like to have this testing done for myself th fallow for my life please. Where can I have this done and have the benefit please.

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