by Erin D Marion - Published 6 months ago

Carbs & Healthy Diet: Dietitian Insights

Can you live without any carbs? Many social media influencers promoting zero-carb diets, like those found on TikTok, seem to think so.

But what do actual health experts, such as registered dietitians, have to say about keto, carnivore, and other very low-carb diets?

"Carbs are essential for feeling your best and maintaining good health," states Daisy Mercer, a dietitian.

While you might technically survive on a very low-carb diet, it's not the type of healthy, balanced diet Mercer suggests.

"We need carbs to think clearly and for many other bodily functions to operate efficiently," Mercer explains.

People are drawn to these very low carb diets because they can provide quick results. Very low carb diets may lead to greater short-term weight loss than low-fat diets.

But does that mean you should drop that sweet potato and snack on a pork chop instead? Here’s what you need to know about low-carb diets and your health.

Are Dietary Carbohydrates Essential?

To answer this fully, there’s nuance to understand here.

Our bodies can actually produce carbohydrates in the form of glucose through a process called gluconeogenesis. If you aren’t eating any dietary sources of glucose, the body uses other compounds to make glucose.

But remember, carbs are the main energy source of the human diet. So while you can technically live without them, you may not feel your best.

According to Mercer, not all carbohydrates are the same. Choosing complex carbohydrates, which are digested more slowly, provides a sustained release of energy. She recommends a diet including a variety of complex carbohydrates, along with plenty of lean protein and healthy fats.

Complex carbohydrates contain more fiber than simple carbohydrates, which are essentially just sugars. Simple carbohydrates are digested quickly, leading to blood glucose fluctuations that can make you feel tired.

Complex carbohydrates, due to their fiber content, take longer to break down, providing sustained energy and keeping you feeling full longer.

What Foods Contain Carbohydrates?

Instead of avoiding an entire food group, it's best to understand how carbohydrates work to reap their nutritional benefits while avoiding potential pitfalls. Many healthy foods are carbohydrates.

These include:

Whole grains: These grains are full of fiber, vitamins, minerals, and other nutrients, offering numerous health advantages. Some examples include brown rice, quinoa, oats, whole-wheat bread, barley, and rye.
Fruits and vegetables: These carbohydrate-rich foods are excellent sources of vitamins and minerals, and also provide a good amount of fiber. Apples, oranges, berries, sweet potatoes, peas, and corn are just a few examples of fruits and vegetables that offer significant health benefits.
Legumes: Beans, lentils, and peas are good sources of complex carbs that also contain a high amount of protein and fiber, helping you feel full for longer.

There is a type of carbohydrates you might want to limit: simple or refined carbs. These include foods made with refined sugars and flours. Think: white bread, packaged snacks, cookies, cakes, and other sweets.

Can the Brain Function Properly on a Low-Carb or No-Carb Diet?

The effects of carbohydrate deprivation on the brain are not fully understood, but research is ongoing.

One short-term study compared individuals on a more balanced diet with those on a low-carb diet.

Participants in the study completed a series of cognitive tests. Those on a low-carb diet performed less well on memory tasks, but they also reported improvements in attention and reduced confusion.

Another small study involving older adults with cognitive difficulties found that a high-fat, low-carbohydrate diet may modestly improve brain function and memory.

Further research is needed to fully understand how eliminating carbohydrates affects the brain.

What Is Keto-Adaptation and What Are Its Advantages?

The keto diet is named after ketones, which can be utilized by the body as an alternative fuel source when glucose is unavailable. When carbohydrate intake is very low (typically between 20g and 50g per day), the liver generates ketones from fatty acids. This process is known as ketogenesis.

When following a no-carb or very-low-carb diet, your body will eventually enter a state known as ketosis. In this metabolic state, your body functions by burning fat for fuel instead of carbohydrates.

Keto-adaptation, a part of fat adaptation, is your body’s way of getting used to using ketone bodies as its main energy source instead of carbs.

Research suggests that people following a keto diet may lose more weight than those on low-fat diets.

However, a diet with very limited or no carbs is hard to follow for most people. There's no proof that staying in a state of ketosis long-term is safe. “Your body prefers carbs and it's not always feasible to restrict your carb intake,” says Mercer.

In general, pay attention to your body — if the keto diet makes you feel tired, dizzy, or grumpy, consider adding some healthy carbs back into your diet.

What Are the Potential Risks of a Zero-Carb Diet?

According to Mercer, a zero-carb diet can lead to short-term issues like brain fog and sluggishness. Constipation and other digestive discomforts can also occur.

In the long run, a zero-carb diet may pose serious health risks. Low-carb diets, such as the keto diet, have been linked to a two-fold increase in the risk of cardiovascular events, including chest pain, blocked arteries, heart attacks, and strokes.

These diets are also associated with:

Nutrient deficiencies
Kidney and liver problems
Mood swings

Tracking macronutrients (macros) has become a popular approach for people to find a better balance of carbs, proteins, and fats. Macro tracking can help individuals reach their health and weight loss goals.

What Is the Most Effective Diet for Weight Loss?

No single diet works for everyone. A registered dietitian can create a personalized plan based on your unique needs. Individual results vary due to metabolism, lifestyle, and health conditions. Before starting any new diet, talk to your doctor to ensure it's safe and suitable for you.