I know that the human body uses carbohydrates to create energy, but it can also use proteins, and therefore I don’t understand if a person can live fine without carbs?
Strictly speaking we don’t need them no. You can function adequately without carbs.
However, carbs are our preferred fuel source. If you use other nutrients you’re taking them away from other bodily processes.
Carbs are also the only metabolic substrate capable of crossing the blood brain barrier. So are important for cognitive function.
In short: you can function and live without carbs. But for optimal function it’s wise to include them.
No, it doesn’t NEED carbs.
You also don’t need a house. Or a car. Or literally anything other than water, protein, and fat.
So, just because you don’t clinically need something, is that in itself a reason to remove that thing from you life?
With 0 carbs, the body has to break down glucose from the liver / start gluconeogenesis to provide the brain with glucose or ketone bodies. Basically, the body is forced into starvation mode. When prolonged, skeletal muscle proteins will be broken down and the body will use ketones to save glucose. Increased ketone bodies can result in ketonuria, which can result in coma or death in serious cases.
Yep, we need carbs. Specifically, varied fiber is an essential nutrient that feeds your microbiome, and carbs in general are delicious and great at fueling you.
You can use fat for energy but it’s quite impractical, it reduces peak performance, and it tends to increase your saturated fat intake which is a huge no no.
You definitely can’t replace carbs with just protein without your kidneys tapping out at some point. And it’d also be a really expensive way to destroy your body.
Fats are the alternative fuel, not protein, but going into ketosis is a horrible week long process for most people, which means everyone going keto tries to stay keto to avoid going through it again, which is extremely socially alienating. This is pretty much the definition of orthorexia. But if you were in the woods… Yeah you could survive on keto for a reasonably long time.
Some sources:
This one is great, with excellent authors and a slew of papers cited:
https://www.medicalnewstoday.com/articles/carbohydrates-are-they-really-essential
I don’t have a really good source for fiber, but this can get you started on a rabbit hole containing 15 years of research by the doctors Sonnenburg:
https://academic.oup.com/aje/article/181/2/83/2739206?login=false
Even more stuff straight from the government. Note that page 30 ( 43 of the PDF ) has a nice chart that shows that people are NOT getting sick while following the dietary guidelines, they’re getting sick because they’re really, really NOT following the guidelines:
Effects of long-term ketosis:
https://www.frontiersin.org/articles/10.3389/fnut.2021.702802/full#h7
Define living- because without carbohydrates (fruits, vegetables, whole grains, dairy or even plant-based milk alternatives that contain carbs) your vitamin and mineral intake suffers, your performance (physically and mentally) suffers. Your risk of certain nutrition-related illness increases (i.e. colon cancer- we do love fiber for this reason). Carbs are great. Vegetables keep your eyes healthy- yay carotenoids…etc. etc.
An adult human needs on average 160 g of carbs a day. Even diabetics because the brain works on glucose and ketone bodies alone using 75% of that daily total. Your liver can make glucose from a few things but not from fatty acids. Your muscles will be fine with no glucose but your brain and nervous system will not.
While we don’t need them in normal quantities, the things we typically replace them with (excess fat and protein) leave us in a less optimal position than if we just consumed a balance of macronutrients.
Carbs aren’t the enemy. Processed flours with no fiber or nutrients whatsoever and added sugars are obviously not great, but whole grains support more than just your energy levels. They promote gut health and keep you full, which is a bonus to those trying to lose or maintain weight.
So, you CAN live off a low-carb diet. But if you’re talking about absolutely zero carbs always for the rest of your life? No, I dont think that’s possible.
This post is so off, so many information in this sub is horrendous. The body NEEDS carbs to break into sugar and consequently create energy to do stuff. Try to be a month without any carbs if you are going to have energy to even stand up. Goddamn..
Edit: You won’t DIE without it but it will make your life really horrible for the rest of it, you’ll lack humor, energy, won’t develop any muscle if you want it.
For how long?
High animal protein causes kidney hyperfiltration and high animal fat causes arterial issues. Humans evolved to eat starches. Our digestive system is much longer than a carnivore.
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The Inuit have a much shorter life expectancy compared to native peoples who eat starch based even though they have adapted to their diet and would fare much better than your average person eating that way.
I don’t know how else you can get the nutrition that you get from vegetable sources. Today just like insulin resistance is huge tomorrow when nutrition improves we will find out how terribly proteins poisonous our bodies. i mean when we overdo protein it turns into carbs anyways. While our bodies don’t absorb carbohydrates the same way as other foods it still has its place. Remember the hunter gatherers were still eating vegetables. In fact that was their main source which they supplemented with meat.
but nutrition today is that it’s very primitive state so I don’t think we will find the answer today. We can make conjectures but we can’t be sure.
The sources of carbs, being fruits, vegetables, grains, and legumes, are absolutely vital for good nutrition. It’s where you get many essential vitamins and fiber. So yes, carbs are necessary.
Strictly as a fuel source, fats and proteins can be used. But without carbs eaten alongside fats and proteins, digestion and absorption will be negatively impacted, and long term there will be serious nutritional deficiencies that will eventually kill you without correction. Also, without fiber, you’ll likely have a rough time in the bathroom.
Yes, humans need a certain amount of carbs, and a certain amount of sugar
Diet culture would have you believe that all carbs and sugar are bad, Cut out all carbs and sugar and do you feel exhausted, plus it can lead to low blood sugar
Some people will even try to tell you fruit is bad because it has natural sugar in it. Fruit!
It’s about balance, a balanced meal of protein carbs and vegetables.
Carbohydrates are not a necessary macronutrient. Your body can make all the carbs it needs to survive. It cannot make all the amino acids or fatty acids it needs so protein and fat are necessary macronutrients.
No I don’t think our bodies NEED carbs but I’ve done low carb diets before and my mood was definitely effected. I’m a much happier person on a diet that is balanced with healthy carbs, fats, and protein.
This is a good break down of carbohydrates, their functions in the body and what the current data has to say about the intake of various types of carbs.
YES! I see people here saying no and that is dangerous!
I would actually like to respond to.thos because this is really danger advice. You 100% do need carbs. Your neurological tissue can ONLY run off of glucose derived from carbs and starches. If you stop eating them your brain will slowly die. Also, you will ketoacidosis and turn blue and die yourself after your liver and Kidney fail.
Your body can go relatively extended period without carbs but NOT forever. You will eventually cause irreparable damage to your liver and kidney and die.
You can certainly do a low carb diet or even survive entirely off of meat (if you eat the whole animal pretty much) but you cannot go forever without carbs.
TLDR: yes you need carbs. Your brain can only use carbs. You can go without carbs for a while but it’s not safe or smart to cut them out forever.
You don’t ND it. But if you want to perform at maximal intensity. Spare some of ur fat or protein then u might want to have it.
There are pros and cons and they all weigh differently depending on the person and how you try to work around it
But in summary. Yes u can live without carbs.
The degree to which we do may depend on lifestage, pregnancy, genotype, activity type, activity level, preferred meal frequency, disease state, genotype of gluco- vs keto-dependent tumor status, and more.
There is no fixed requirement for dietary carbohydrate for most humans at most lifestages for most health conditions. My guess though is that many people today on most places can benefit from a reduction overall and a crafting of type of carbs.