Slow-carb, not low-carb
Updated: Feb 24
What is the difference between slow-carb and low-carb?
A low carb approach means that 25% or less of your daily calories come from carbohydrates, which may sound like it is a good idea, right? Keto means less than 50g of carbs. There go things like carrots and colorful veggies. Not to mention the negative impact on our gut.
Let me introduce you to slow-carbs and why you need them:
There have been actual studies, like this one here, that found going low-carb for four weeks resulted in a 50% reduction of bifidobacteria! Along with a decrease in concentrations of butyrate-producing species and fecal butyrate. Butyrate is very important to overall health and is one of three short-chain-fatty acids. Bifidobacteria bacteria is one of the most important bacteria types in our gut, and low levels have been associated with poor health outcomes. Below I link out to even more studies that suggest that a low-carb, high fat & protein diet can really do a number on our gut health.
There is no such thing as an essential carbohydrate like there are essential fatty acids and amino acids. However, we know the profound impact healthy slow carbs have on our body by enhancing our gut health. Side note: All veggies are carbs, and things like legumes and fruits are carbs.
Also, we know our gut microbes love diversity! The more plant variety, the better. This can be very challenging when following a low-carb diet as we tend to stick to things like lettuce and arugula and miss out on all the other amazing veggies.
What do I mean by slow-carb?!
Slow carbs are broken down slowly. Hence the name. They are broken down slowly because they are wrapped in fiber. Dietary fiber is the carbohydrate found in plants that cannot be digested, and we do not absorb it. It is what we call a complex carb. So if we cannot breakdown fiber, who can? Our gut microbes! This is often why when people add more fiber to their diet too quickly; they feel bloated and gassy. They don't have the microbes to break it all down, so I always suggest going slow and low with fiber when starting out.
More on Fiber:
Fiber, prebiotic fiber, to be specific, produces short-chain fatty acids, which regulate fat metabolism by increasing fat burning and decreasing fat storage. Fiber also helps us feel fuller longer and slows blood sugar from spiking too high. This keeps energy levels steady and cravings in check. The higher in fiber, the lower in glucose, and the less blood sugar your body needs to manage. The different types of fiber will feed different types of bacteria. Variety is key. There are two types of fiber: soluble and insoluble.
Back to slow-carb and low-carb:
By eating carbs that break down slowly and feed our gut, we can enjoy things like chickpeas and black beans and not have this "uh, this will make me gain weight" type of feeling.
Here's the catch: we all have a unique carbohydrate threshold, which comes down to things like serving sizes. For most people, 1/2 cup of slow carbs is their sweet spot. This helps keep blood sugar in check. This is important for gut health as we know elevated glucose levels can also break down tight protein junctions (hey, leaky gut!).
If you're dealing with blood sugar issues, I also suggest eating your carb item last. Yes, you read that right! Eat your greens & non-starchy veggies (extra slow carbs; see below), protein, fat, and then your carb. Here's an actual study showing eating your carb last can improve blood sugar. This is especially helpful with things like sweet potatoes, which are more like a quick-carb than a slow-carb. Sweet potatoes are mainly starch, but you can still enjoy them! I love them! Make sure to pair them with a balanced meal and eat them last.
I'm breaking slow carbs down into two groups: Extra Slow and Slow
Extra slow carbs: aka non-starchy veggies - these are unlimited
Greens (spinach, kale, romaine, swiss chard & arugula), carrots, tomatoes, garlic, onions, mushrooms, zucchini, pepper, eggplant, celery, cucumber, radish, broccoli, artichokes, asparagus, cabbage, cauliflower, Brussels Sprouts, and things like parsley, basil, mint, and cilantro
Slow Carbs - still slow, just not as slow - these are great in moderation:
Gluten-free whole grains such as quinoa, millet, buckwheat, brown, black, and red rice
Beans such as lentils, black, red navy, and white beans, edamame, into and adzuki beans (I know I'm missing some beans, but you get the point)
Kinda slow, but kinda not: The starches
These are starchy, high-glycemic vegetables such as sweet potatoes, butternut squash, winter squashes, peas, potatoes, corn, and beets. These are not off limits! We know they offer great nutrients, but we also know they raise blood sugar more quickly, so enjoy in smaller quantities and have them at the end of your meal.
Blueberries, cherries, blackberries, and raspberries
Not to say you can't enjoy watermelon, grapes, and pineapple, which are higher in sugar and break down more quickly, just pair them with a meal or some nut butter. If you find things apples bloat you that is not the glucose that is fructose. This is known as fructose malabsorption or intolerance.
Quick carbs: You guessed it, things like bread, pastas, white rice, packaged goods (even gluten-free white breads) and refined carbs. These are not off limits, but knowing that break down very quickly and cause both blood sugar spikes and inflammation, I wouldn't enjoy every single day. Let's bring this back to the gut shall well we. Increased inflammation is linked gut disruptions and even leaky gut.
Takeaway: Balanced blood sugar is a key component of a balanced gut. Your adrenals perceive mismanaged blood as a stressor and respond by sending out cortisol. We know cortisol can induce negative changes in gut health and hinder digestion. Not to mention repeated levels of high blood sugar can result in inflammation. This systematic inflammation can negatively impact gut health.
Set a small goal to get in veggies and/or plant fiber at every single meal, build two out of three of your meals around extra slow carbs, and add some slow carbs like black beans all of which feed gut health!
More studies on low carb and poor gut health: