Debunking the Low-Carb Trend

One of the most popular dieting trends I wish my clients had a better understanding of is the low-carb diet. I can’t tell you how many times I’ve heard, ‘no carbs, no sugar’. Did you know carbs are in fact sugar? It’s like saying, ‘no meat, no chicken’ – a bit redundant, no? I can see how much confusion there is around this subject which is why I want to address all the reasons you don’t need to fear carbs. Let’s start with some history.

When Did We Start Fearing Carbs?

Way back in 1864 a man named William Banting wrote a booklet recommending a low-carb diet after he lost weight. He was so alleviated from the weight stigma he’d previously endured that he felt inspired to share about his supposed success. He claimed feeling and sleeping better just a few days after cutting out potatoes and sugar. While I don’t doubt he actually experienced those benefits, I have to look at the bigger picture. Was he feeling and sleeping better purely because he cut out starchy and sugary carbs, or because he started introducing nutrients that were severely lacking beforehand? 

On top of that, experts theorize that Banting likely had undiagnosed type 2 diabetes since he reportedly struggled with his vision and hearing, had an irregular heartbeat and multiple skin abscesses. If that was the case, adding fiber in the form of fruits and green vegetables would certainly result in better sleep and improved glucose levels. This is just a typical example of how narrow-minded we can be when it comes to nutrition science.

What Exactly Is A Carb?

The food we eat is composed of micronutrients and macronutrients. Micronutrients refer to vitamins and minerals that help our body function properly, and macronutrients (carbs, fat, and protein) provide energy. Humans have been eating carbohydrates for over 170,000 years. They’re a foundational part of our diet and every culture consumes them in one form or another. We can further classify them into one of three categories: sugars, starch, or dietary fiber. Let’s break each one down.

Sugar

Sugar is the generic term for all sweet-tasting simple carbohydrates. The 3 simplest sugars (also called monosaccharides) include glucose, fructose, and galactose. When two simple sugars join together, they are called disaccharides. These include sucrose (which we call table sugar) and lactose (milk sugar).  Glucose is the most significant monosaccharide because it is present in all disaccharides, and it’s the main source of energy for the brain. The main two sugars are glucose and fructose. They’re created by plants (and animal milk) to be converted into energy and spread by fruit-eaters to distribute their seeds. 

This form of carbohydrate is always demonized, and yet studies show that if you substitute sugar for fat or protein and maintain overall calories, weight does not change. The reason higher sugar intake gets correlated with weight gain is because sugar is highly palatable, calorie-dense, and isn’t very satiating (filling). Overeating any macronutrient can lead to weight gain.

Refined Carbohydrates

This is another descriptor for sugar that’s also used to imply something is processed. White flour, for example, is mostly starch and therefore a complex carb, but because the fiber is mostly removed it gets called ‘refined’.

Starch

Just like humans store energy as fat, plants store it as starch (complex carbohydrates). This group includes non-sweet carbs (cruciferous vegetables, root vegetables, legumes, beans and lentils, and grains). Any flour-based food like bread or pasta also falls into this category. This is where most of our micronutrients and fiber come from.

Dietary Fiber

Dietary fiber includes all the remaining carbohydrates from plants that we don’t properly digest or receive energy from. Some ferment to maintain colon health and the rest bulk our stool to prevent constipation.

How We Digest Carbs

Have you ever seen a visual for how many sugar cubes are in different sources of carbohydrates? Knowing there are 20 sugar cube equivalents in a bowl of rice isn’t very helpful if we don’t understand how our bodies digest and absorb them. First off, our body’s preferred source of energy is the simple sugar glucose. In order for our blood stream to absorb simple sugar, our gut has to break them down first. This process naturally makes our blood glucose levels, or blood sugar levels, rise. Things like fiber can slow down that process so the rise is more gradual. 

There’s a lot of fearmongering around blood glucose level ‘spikes’. In reality, only about 4% of healthy people experience ‘spikes’ after eating a sugar-dense meal. Not only that, but we have zero current evidence that spikes cause problems in the future, even though everyone believes eating sugar causes diabetes (it doesn’t). That doesn’t mean it isn’t beneficial to slow down the absorption of sugar for longer-term energy, just that you shouldn’t be worried if that’s not what happens!

Did you ever try a low-carb diet and end up feeling crummy? That’s because your brain requires 20% of your body’s total supply of sugar a day! Glucose rises after the gut absorbs the carbohydrates from what we eat, and then insulin takes the glucose from the blood to be used for energy. Blood glucose levels typically rise more than necessary so insulin stores some of it as glycogen and some of it as body fat. This is not a problem. This helps manage the surplus so that between meals there are reserves ready to return to the blood. Insulin consequently gets a bad rep since its job is to store fat, when it’s thanks to insulin that we can sleep through the night without having to wake up to eat every few hours to keep our blood glucose levels steady.

Carbohydrates Are (Non)Essential?

This reductionist mentality about food is technically true since glucose can be made from both protein and fat, but having a healthy relationship with food means viewing it as more than nutrients alone. Limiting ourselves to only what is essential for survival means we rob ourselves of the pleasure, connection, community, and celebration that carbohydrates also provide.

Carbs=Fat

A 2017 meta-analysis and systematic review that compared low-carb and low-fat diet weight loss found zero meaningful benefit in body fat loss or daily energy expenditure. In fact, one study found that those who followed low-fat diets lost slightly more weight (not that I support low fat diets either).

Japan is one of the top consumers of carbs, eating white rice with almost every meal and they still have the lowest ‘obesity’* rate. Meanwhile, US carbohydrate intake has fallen over the years while average body size continues to increase. Weight gain is clearly more complex than carbohydrates alone.

Why All the Hype?

When changing to a low-carb diet, glycogen stores (which are 3 to 4 parts water) initially get used up since there aren’t enough carbs being eaten. In the end, the reason people believe low-carb is so great is really nothing more than water weight lost.

I hope that with all of this information you no longer feel the need to buy the ‘low-carb’ bread alternative and can enjoy your favorite comfort food (I can guess it’s heavy on the carbs!) without feeling guilty or ashamed. If you still have work to do in this department, I have a free Anti-Diet Facebook community I would love for you to join. If you’re looking for 1:1 guidance through the process of unlearning the diet mentality, I invite you to fill out an application for coaching, or you can schedule directly with me here!