Carbohydrates are an important macronutrient group. Carbohydrates are literally just a supply of sugar for the body and, you will learn from our articles, sugar is the number one energy source for the body. The sugar our body uses for energy is called “glucose” and our body has a few different ways it can manufacture glucose in the absence of Carbohydrates but that’s an article for another time. In this article, we’re going back to basics to understand whether carbohydrates influence weight loss and you might be asking “Will reducing my carb intake make me lose weight?” and the short answer is that it’s entirely possible to support weight loss using a low-carb diet.

Before we carry on, I need to issue a disclaimer to say that this article, nor any articles on our website, acts as a substitute for independent, qualified nutrition advice. This article and others are intended for informational purposes only and bear no consideration for your individual dietary and nutritional needs. Before acting on any dietary or nutrition information you read online, please consult with a registered dietician or nutritionist.

Carbohydrates stimulate hormones in your body, such as insulin, to enable efficient management of energy within the body. Insulin is a hormone that you’ll likely associate with diabetics; diabetes is a condition that occurs when the pancreas cannot produce enough insulin or when the body cannot effectively use the insulin it produces to manage blood glucose. For those who don’t live with diabetes, our body is able to produce enough insulin to manage our blood sugar levels effectively.

As we consume more carbohydrates, our blood sugars rise and more insulin is produced to transport the sugar from our blood into our cells; our muscles, our skin, our fat cells and even our brain cells! But over time, our cells develop a resistance to this insulin and the cells don’t accept the blood sugar, this causes blood sugars to become uncontrollable and type 2 diabetes will present itself.

Diets that are high in carbohydrates, especially simple (and refined) carbohydrates, are generally associated with weight gain because of the storage effect; when our cells no longer need sugar, the sugar is converted into glycogen and stored as fat and when we’re constantly overdosing ourselves with sugar, there isn’t enough time for our insulin to effectively store the sugar and unmanaged, this could lead to significant health problems associated with diabetes.

Adopting a low-carb diet reduces the activity of storage hormones and, in turn, helps with weight loss because it prevents additional weight being gained through fat storage. The key to a healthy diet is to have a balance of carbohydrates, proteins and fats and not to eliminate all carbohydrates but with that being said, each of us has a unique dietary needs profile and it’s important to manage our macronutrition properly – assistance from Andrew Hill, a fitness professional and nutrition expert, is freely available to DietPal customers.

The argument for equal balance is a fallacy though – this guideline is based on the average healthy person. If you’re not an identical copy of that average healthy person, your nutritional needs will be different and it’s important to understand where adjustments need to be made. If you’re living with morbid obesity then it is likely you require fewer carbohydrates than somebody whose of an average body weight and regularly runs cross country; it is likely that a morbidly obese person would benefit from much fewer carbohydrates and an increased protein and fat diet (we will run an article on why “fat” in foods gets an unfairly bad rap another time; fat is key to absorption of most micronutrients including many important vitamins and is an absolutely essential nutrient). Protein makes us feel fuller for longer and inhibits the production of a hormone called “ghrelin”, the hunger hormone. Protein is good.

You shouldn’t eliminate carbohydrates too much, though. They are the body’s preferred and only source of energy because even when our body uses protein (muscle) and fat as energy, it breaks these down into glucose through a process called gluconeogenesis. Your brain and red blood cells rely exclusively on carbohydrates (glucose) to function. Without enough carbohydrates, you won’t have the energy to fuel your body and brain and you might develop flu-like symptoms and suffer from exhaustion, especially if you’re deficient in other areas of your nutrition. People who engage with ketogenic diets, where they cut out carbohydrates all together in favour of a high fat diet instead, will often suffer from “keto flu” for a couple of weeks until their body adjusts to a new energy source. Keto diets are dangerous, in my opinion, if they’re not undertaken with qualified supervision but they are also extremely effective. But don’t do it, it isn’t worth the risk. Stick with me and we’ll achieve the same results in the same amount of time without cutting out the foods you love.

Good sources of carbohydrates include vegetables, fruits, whole grains and low-fat dairy products. The carbohydrates you should avoid are refined ones such as white bread, white rice, pasta, cakes and cookies. The way I identify a good carbohydrate is by considering whether it is a wholefood or whether it is ultraprocessed. A wholefood is one that resembles the original thing as it grew on or in the Earth; if a product has chemicals in it then it isn’t a whole food and it’s probably better off being put back on the shelf.

When we reduce our carb intake, it forces our body to rely on other sources of energy, the preferred secondary source of energy is protein which is bad news if we want to retain our muscle mass (and let’s be real, none of us want to lose weight, we really just want to lose body fat and be slim!) Our muscles store glycogen, glycogen is like dozens of glucose molecules bonded together to form a web (or a multibranched polysaccharide if you want to be technical!), these bonds can be quickly liquified during glycolysis and the energy is then readily available. Glycogen is stored in muscles in this way because when it is needed during intense exercise, it can be readily broken down and transported directly into the muscle that needs it whereas to use glucose for energy in our muscles, our muscles would have to wait until our intestines have absorbed it through what we eat and then slowly transported it to where it needs to go. Our blood stream has no way or prioritising where sugar is dropped off, our body also cannot tell our blood stream where to deposit energy but it is able to force blood flow to different parts of the body but it means that if our bicep needed sugar for exercise, but so did other body parts along the way, the body parts along the way would be fuelled first. Our body is an amazing thing and glycogen allows our muscles to have its own little jerry can of fuel on board at all times. When our body runs out of glycogen stores, when we feel lethargic and achy after exercise, our muscles have no choice but to wait and that’s why rest days are so important and why we can’t just continually exercise and exercise to try and outrun a bad diet. Our body will simply run out of fuel the same way a car does and just come to a halt.

But how do we prevent our body from liquefying glycogen stores for energy when I want to lose fat? It’s easy. You just need to engage in strength training exercises regularly and maintain a higher protein intake. This will enable the body to recognise that it needs glycogen because of the exercise and it needs protein for rest and recovery so instead, it will seek energy from its final energy option, and that’s the starchy material stored as lipids in fat calls. Through glycolysis, lipids are converted into sugars (fun fact, we never lose our fat cells, they just empty) and through this, our body fat reduces and therefore, so does our weight.

In summary, yes, reducing your carbohydrate intake may help you lose weight, provided you are in a calorie deficit. If you are consuming more calories than you consume, you will not lose weight because of physics. But reducing carbohydrate intake not only helps you to lose weight but is instrumental in helping your body to lose body fat; body fat will only be used as energy and therefore reduced when there is no other preferred energy source available.