The idea of restricting carbohydrates seems to be an extreme dieting approach to many people. After all, we’ve learned that carbohydrates provide important benefits, such as fueling the brain and body.
However, the ketogenic diet limits carbohydrates to just 50 grams or less per day, to stimulate ketosis — a metabolic state in which ketone levels rise. This way of eating can make a person ask, “Do you need carbohydrates in your diet or are they necessary for survival?”
If you’re interested in carbs and possibly on the keto diet, this guide explores carbs and their role, whether you need them, research studies on low-carb diets, other expert opinions, and more.
What are carbohydrates?
Carbohydrates (or carbohydrates) are a macro (or macro) nutrient along with other macronutrients including protein and fat. They come in different types such as sugars, which are simple carbohydrates, and starches and fibers, which are complex carbohydrates.
During digestion, sugar and starches are converted into glucose. If your body does not use glucose, it can be stored as glycogen in the liver and muscles. Otherwise, large amounts of carbohydrates — or unused carbohydrates, as when you eat more calories than you burn — are stored as fat (*).
Meanwhile, your body does not digest the fiber. The study shows that these “indigestible carbohydrates” increase the diversity and richness of the gut microbiome
.
Foods that contain carbohydrates include vegetables, fruits, grains, nuts, seeds, and dairy products, especially unhealthy sources such as soda, packaged snacks, sweets, and other processed foods.
The role of carbohydrates in our bodiesCarbohydrates act as fuel because carbohydrates are converted into glucose, and glucose provides energy. However, this only applies to individuals who get the most calories from carbohydrates — about 45% to 65% of total calories, based on the Dietary Guidelines for Americans (
*).
However, while eating low carbs, your body can make use of ketones as an alternative fuel in place of glucose. The truth is that you can do this on purpose – restrict carbohydrates and induce dietary ketosis – to reap its health and weight loss benefits (*, *).
Do we really need carbohydrates in our diet?
For many years, cutting carbohydrates from your diet has been considered unsafe and unsustainable. Despite this belief, there is strong evidence that your brain and body do not need carbohydrates to function and thrive. We’ll cover some studies of low-carb and ketogenic diets and their impact on health later in this article.
In the meantime, here are some points to support the idea that carbohydrates aren’t necessary:
There is no set minimum carbohydrate limitCarbohydrates are the only macronutrients that do not have a minimum requirement (
*). In fact, the Food and Nutrition Board of the Institute of Medicine of the US National Academies of Sciences states
:
Browse our curated collection of fan favorites and discover your new favorite snack or supplement.
Shop the best sellers
“The minimum life-compatible dietary carbohydrate appears to be zero, provided adequate amounts of protein and fat are consumed.”
Early evidence of endurance while in ketosis
Schwatka’s 1878–1880 flight was one of the earliest documented evidence of physical endurance in the ketogenic state. The leader of the campaign, Lieutenant-General Frederick Schwatka, wrote in his diary
:
“When it is first thrown entirely on a diet of reindeer meat, it appears to be insufficient to properly nourish the system, and there is obvious weakness and inability to undertake severe stressful journeys. But this soon wears off within two or three weeks.”
Meet your micronutrient needs
Focusing on a variety of whole foods that are low in carbohydrates can provide your body with the right amounts of micronutrients (vitamins and minerals). These have critical functions, such as energy production, muscle contraction, and fluid and electrolyte balance.
Just because you’re cutting carbs, doesn’t mean you’ll be missing out on important micronutrients.
Glucose synthesis from non-carbohydrate sources
Are carbohydrates necessary to produce glucose for energy?
Before answering this question, it is important to note that some cells only depend on glucose to function because they lack mitochondria (their primary function is ATP production). This includes mature red blood cells and mature lens fibers (*, *).
On the other hand, fast-twitch muscle fibers (Type IIX or IIB), which are involved in vigorous movements such as running, jumping, and weightlifting, have low mitochondria. They also tire more quickly
So, does the body need carbohydrates to make glucose? The answer is no.
- Add more delicious dishes to your inbox
- Sign up for new simple, easy, and insanely delicious keto recipes every week.
- Hey, you! We will send you delicious recipes once a week 🙂
- However, whether this information is known to people or not, some still choose to incorporate carbohydrates for personal reasons:
To add variety to their diet especially if they have a high ‘non-negotiable’ carb or favorite foods.
They consider some carbohydrates to be their comfort food because they taste so delicious (for example, ice cream, pizza, chocolate, etc.).In the bodybuilding community, to make muscles look “full” is because carbohydrates retain water in the muscles.
They find that adding carbohydrates gives them extra energy power through intense workouts, such as those that involve sudden bursts of energy like sprinting, jumping, weightlifting, and high-intensity cycling.
What happens when we don’t eat carbohydrates?
Cutting out carbs too much will lead to short-term symptoms such as headaches, fatigue, muscle cramps, and digestive problems (
constipation or diarrhea), bad breath (also known as ketogenic breath)
.
Collectively, these symptoms describe the keto flu. This is your body’s natural reaction when you withdraw from carbohydrates. You will experience it within a few days of cutting back on carbs and may last anywhere from a week to a month depending on your adaptation
.
Furthermore, you will likely notice a decrease in water weight. This significant weight loss occurs in the first week of limiting carbs because your body uses up glycogen (the storage form of carbohydrates associated with water) and begins to utilize fats..
The liver produces ketones from the breakdown of fats, which you will be able to measure more accurately with a ketometer or ketone test strip.
Sticking long enough to a low-carb diet (also known as the keto diet) allows your body to get used to ketones for energy. During this time, the symptoms of the keto flu disappear. Furthermore, keto dieters reported seeing higher energy levels, decreased appetite, sustained fat loss, improved mental clarity, and improved cholesterol.
.
What the research says about low carb and keto diets
Many people assume that there is not enough research on keto and low carbs. So, here are a handful of studies that may help you better understand the impact of this dietary approach on your health, fitness, and performance:
Research on type 2 diabetes
While type 2 diabetes is usually managed with a low-fat diet and antidiabetic medications (which promote weight gain), a study with 238 participants showed impressive results. After 10 weeks of the individualized program that included nutritional ketosis, participants were able to better control blood glucose, lose weight, and were able to reduce medication use (
*).
The search for obesity In a one-year controlled trial, 63 obese men and women were assigned to a low-carb, high-protein, high-fat diet or a low-calorie, high-carb, low-fat diet. Note that these people were not pregnant, breastfeeding, or taking any medications that might affect their weight. Results during the first six months showed that a low-carb diet resulted in greater weight loss, around four percent
.
Research on cardiovascular disease risks
A 2020 meta-analysis assessed the relationship between low-carbohydrate diets and the risk of cardiovascular disease. Data were collected from 12 randomized trials. In conclusion, a low-carbohydrate diet was significantly associated with lower weight, lower diastolic blood pressure, plasma triglycerides, and fasting blood glucose levels. Furthermore, there was an increase in the levels of good HDL cholesterol .
Finding endurance with exercise
Five male endurance-trained cyclists volunteered for this study. The results showed that although muscle glycogen content was lower at the start of moderate-intensity exercise, they felt less tiredness when following a high-fat diet. The findings suggest that delayed fatigue may be related to the body’s increased ability to burn fat for fuel (or fat oxidation).
.
.
Related articles:
Building Muscle on Keto: The Ultimate Guide
Research into brain health
The ketones produced in a low-carb diet help improve the energy crisis found in neurodegenerative diseases such as Alzheimer’s disease, in which glucose metabolism in the brain is reduced. Furthermore, clinical studies show that ketone bodies protect nerves and that cognitive benefits have been observed in Alzheimer’s patients or those at risk of developing the disease.
.
Related articles: Ketones to fuel the brain and metabolism
Other experts’ opinions on dietary carbohydrates
Some experts oppose or don’t recommend eating low carbs at all for various reasons such as saturated fats (where fats become your alternative fuel instead of carbohydrates) being bad for the heart. Regarding this belief, there is no evidence that reducing saturated fat reduces the incidence of cardiovascular disease. Furthermore, replacing fat with a diet rich in carbohydrates may increase the risk of death . Another common belief among non-low-carb experts is that dietary ketosis impairs an individual’s energy and exercise performance. Properly following the keto diet, such as ensuring adequate electrolytes and fat intake, and allowing ketogenic adaptation, will improve the body’s energy needs. So, can we survive without carbohydrates? Does your body need carbohydrates to gain energy, synthesize glucose for tissues that rely solely on this fuel, meet your micronutrient needs, and maintain muscle mass? No, we don’t need carbohydrates to live and function at our best. In fact, limiting carbohydrates while eating adequate amounts of protein and fat has many advantages, from controlling blood sugar to maintaining weight loss. But at the end of the day, what you eat is a personal choice. Despite the available research on low-carb and ketogenic diets, some people still find cutting carbs too restrictive. This is where a long-term commitment becomes difficult — but not impossible! However, if you’re considering a keto diet, it’s important to keep in mind that ketosis (or the body’s ability to efficiently use fat as primary fuel) takes time. At Perfect Keto, we have supported people on their keto diet journey, allowing them to achieve life-changing results. Feel free to check out our success stories and get started today.Add more delicious dishes to your inboxSubscribe for new simple, easy, and insanely delicious keto recipes every week. Hey, you! We will send you delicious recipes once a week 🙂25 References
Discussion about this post