Are carbs really necessary? Since the 1990s, government dietary guidelines have led us to believe the answer is yes, processed carbs made from processed or whole grains, such as bread and pasta, are a necessary part of our diet and daily calories. Ditto less-processed carbs like legumes and brown rice. But recent studies and the health of our nation suggest that much of what we were taught about carbs and fat is simply not true. In fact, evidence suggests that in order to survive and thrive and enjoy a “balanced diet,” we don’t need carb intake the way we thought we did. It also suggests that it’s fat that’s essential to our well being.
How Did We Get Here?
We didn’t just wander into our current thinking about “proper” nutrition. Our carb-centric perspective ties back to a dietary edict perpetuated by the food industry in the 1980s: fat is the enemy of optimal health. In the early ‘80s, the notion of a low-fat diet became synonymous with healthy living, at least partially due to food manufacturers, who seized the opportunity to profit from and expand the growing low-fat trend. An article in the Journal of the History of Medicine and Allied Sciences explains what came next: “Driven by consumer demand and widespread advertising, in the 1980s and 1990s, low-fat industrial foods proliferated to fill grocery store shelves. In 1992, after much controversy and negotiation, the USDA released its first and long-awaited food pyramid that lent full support to the ideology of low fat.”
What does a low-fat food pyramid have to do with carbs? Well, everything. First, without lots of fat calories to help people reach their daily macros, they had to get energy from somewhere else, and that somewhere was likely from a good amount of carbs. Second, when food manufacturers removed fat from dairy, cookies, crackers, and other packaged foods, they added more sugar (higher amount of carbohydrates/added sugar) and food additives to make their products taste more appealing. As a result, consumers ended up eating more carbs during their daily calorie intake (and spike their blood-sugar levels and avoid weight loss) just by eating low-fat. Just like that, the dietary paradigm shifted, and our health as a nation went with it. (Hello, type 2 diabetes and heart disease.)
The Big Carb Con
According to today’s research, the currently established essential nutrients for humans are water, energy, amino acids (found in protein), essential fatty acids (found in fats), vitamins, minerals, trace minerals, electrolytes, and ultra-trace minerals. All of these can be obtained from a diet of healthy fat and protein. What’s not on this list? Carbs. We can get all of our functional nutrient needs met without eating carbs! Let’s digest that for a second. That food pyramid we studied as kids in school–the one with the largest percentage of daily macros coming from grain foods–is not just wrong, it’s dead wrong, and obesity, illness, and earlier mortality are the price we are paying for this misdirection.
To better understand why this is the case, let’s first get a simple understanding of what carbs are.
What are Carbs, Actually?
Carbohydrates are sugars, starches, and cellulose. Carbs are divided into two categories: simple and complex. Simple carbs come from sugar, candy, vegetables, and fruit. They are short chains of sugar molecules (monosaccharides). Complex carbohydrates, found in starches like bread, cereals, and pasta, contain longer chains of sugar molecules linked together and are more complex (polysaccharides).
Is one really better for you than the other? Plainly put, yes. More complex carbs are digested slower than simple carbs, and therefore don’t spike insulin as quickly, creating less of a “blood-sugar roller coaster” effect on the body. Regardless, both short- and long-chain carbohydrates are digested and broken down into simple sugar molecules in the body, which are then used by the body for energy or stored for later use as fat.
So, Should We Avoid Carbs Altogether?
Our bodies function just fine with limited to no carbohydrate intake, and restricting carbs can actually improve our health and well-being. So, are we recommending a no-carb diet? Not necessarily. Unless you are on a keto diet as a therapeutic treatment for a medical condition, you can consume up to 20 net carbs per day on a keto diet regardless of your optimal macros (macronutrients). (That’s not a lot. In fact, it’s very little. One banana has more carbs than that!) But we’re not talking just any carbs. If you want to keep a small number of carbs in your diet, we recommend getting them from above-ground vegetables (think veggies that have few grams of carbohydrates per serving, like broccoli, cauliflower, spinach, kale, peppers, and zucchini), which contain vitamins, minerals, enzymes, protein, fat, and fiber and don’t spike your blood-sugar as much as starchier or more sugary carbs.
Additionally, we’re talking 20 net carbs, which is different than 20 total carbs. Net carbs are the grams of carbs a food contains after you subtract grams of fiber (and sugar alcohol). The reason for this makes sense: although fiber is technically a carb, our body does not digest and assimilate fiber. Therefore, we don’t need to account for it. You can learn more about net carbs here. There are some helpful keto apps available to help track your goals and macros that we review here.
The Importance of Fat in the Diet
So how do we get energy without carbs? Believe it or not, the answer is FAT! Evidence has shown that fat is the best source of energy and is also very important for brain health, hormone health, skin health, and yes, even heart health. But not just any fat will do. The type of fat matters. Experts agree we want to avoid heavily processed vegetable oils, like canola oil and vegetable oil, as well as hydrogenated oils like Crisco. We also need to be mindful of the ratio of omega-3 fatty acid to omega-6 fatty acid since excess omega-6 fatty acids have been linked to obesity. The best fats for our health are found in coconut oil, extra-virgin olive oil, macadamia nut oil, avocado oil, avocados, certain nuts, and animal fats such as bacon fat, tallow, and lard.
Using Fat for Energy
On a carb-heavy diet, when your body needs energy, you crave carbs. Then, once you eat them, your insulin stimulates the liver to convert the carbs (blood glucose/sugar) to glycogen. (The liver can also generate glucose from amino acids, this process is known as gluconeogenesis.) Glucose that is not immediately used by the body is stored in the liver and muscles for later use, or it’s stored as fat if consumed in excess of what the body needs for energy. But when carbohydrates are severely restricted (like on the keto diet) and you eat ample fat, the body is forced to use fat as its energy source, and it does so by breaking down fatty acids (fat from your diet and your body) into ketones via your liver. This process is called ketosis, and it has magical results: you lose carb cravings, feel less hunger, gain more energy, and, provided you limit your food intake and stay within proper daily macros, burns your body’s fat stores.
So, though the body can use carbs for energy, fat is a much more efficient source of energy. It also has more nutrient density and health benefits. Why? Look at it this way: Let’s pretend you’re starting a fire, and all you have is kindling. Since kindling burns so fast, you’ll need repeatedly add it to the fire to keep it burning. It’s the same with carbs. They burn fast, so you need to add more and more to keep your energy up. But, if you add a big log to the fire, you can relax, sit back, and let it slowly burn. Fat for energy, which is only accessible with the restriction of carbs and the consequent production of ketones, is like that slow-burning log on the fire; it’ll keep you glowing and going for a long time, even when you have high activity levels.
Other Benefits from Ketones
Along with providing energy, ketones offer other health and wellness benefits:
- Protects the brain: neurological and brain disorders as well as a traumatic brain injury.
- Provides an alternative (and preferred) source of fuel to the brain
- Reduces inflammation in the body (the root cause of autoimmune diseases like Hashimoto’s, Crohn’s Disease, & Celiac)
- Increases Fat loss and deters weight gain
- Increases energy
- Protects against mitochondrial dysfunction (where energy is produced)
- Helps with depression and anxiety
The Final Word
Contrary to a longstanding belief, carbs are not necessary for your body to function or for your health, and your body functions much more efficiently on a the ketogenic very low-carb diet. Regardless, it’s important to check with your primary care physician or a registered dietitian before dramatically changing your diet and meal planning.