24 Mar Should you be cutting carbs for weight loss?
By Hannah Buckland – Healthy Hearts Care Planner
We just want to take a moment to say that, due to the current situation around Covid-19, we realise that diet may not be top of your priority list – and we completely understand. We also acknowledge that you may consequently have less control over your diet than you would like, and that shopping can be a stressful time right now. If you want to save this article to read at a later date, then no problem! Alternatively, the information provided might help to reduce some of the anxieties you are feeling around food at the moment. Bear in mind that our team are still here for you (virtually!), and if you would like to talk about diet with one of our advisors we are just a phone/video call away. Wishing you all the best in this uncertain and difficult time.
Carbohydrates tend to be quite a controversial topic in nutrition, especially when it comes to weight loss. There seems to be a general perception that ‘carbs are bad’; you’ll often hear people say, “I’m cutting carbs to lose weight” or “I’m on a low-carb diet”. Indeed, many popular diets have emerged based on this idea – Atkins, South Beach and Keto to name just a few. So, what does the science say about the effectiveness of low- or no-carb diets?
Let’s start by explaining a little bit about what carbs are. Carbohydrates are one of three macronutrients (the others being fats and protein), which form a large part of our diet. There are three different types of carbohydrate: sugar (often added to food or drinks, but also found naturally in foods like yoghurt and fruit), starch (bread, rice, potatoes, pasta) and fibre (found in fruit and vegetables, wholegrains and pulses). All types of carbohydrate are broken down into glucose, which is then used by your body for energy. The government recommends that just over one third of your diet should be made up of starchy foods, and over another third should be fruit and veg. Therefore, over half of your daily calorie intake should come from carbs, making them your main source of energy in a healthy, balanced diet.
So why do so many people (including the media, health professionals and scientists) promote low-carb diets for weight loss? There is a theory, called the carbohydrate-insulin hypothesis, which suggests that eating carbs causes insulin levels to rise, meaning less fat is broken down in our bodies and more is moved into storage. The idea is that if you follow a low-carb diet you will lower your insulin levels and burn more fat. However, studies have shown that the amount of carbs you consume has little to do with how much fat you burn, regardless of the amount of insulin in your body. What’s more, research shows that carbs don’t cause you to gain weight any more than fat. The truth is, any food can cause you to gain weight if you eat too much of it; at the end of the day, it’s calories rather than nutrients that will impact your weight. So, the science doesn’t indicate that you need to follow a low-carb diet to achieve weight loss. As with calories (see previous article), it’s the quality and quantity of the carbs that is key. If over half of your daily calorie intake is coming from processed carbs such as pizza, sugary cereals, cakes and biscuits, that’s a very different story to if your intake comes from fruit, vegetables, wholegrain pasta and pulses. In fact, high fibre starchy carbs can actually help with weight maintenance, as they will release glucose into the blood much slower than processed, sugary foods and drinks and therefore help you to feel fuller for longer.
What’s more, quality carbs such as fruit and veg, wholegrains and pulses have been linked to a number of health benefits. High fibre diets are associated with reduced cholesterol levels, as well as a lowered risk of cardiovascular disease, bowel cancer and type 2 diabetes. Since most of us do not manage to achieve the recommended intake of 30g fibre a day, reducing carbs could further prevent us from achieving our daily fibre recommendation. Carbs can also be a great source of vitamins and minerals – such as those found in fruit, vegetables and pulses. By restricting carbs, over the long term you could become deficient in certain nutrients which could negatively impact your health. There is also the risk that reducing carbs will lead to an increased intake of fats and proteins, which could increase your intake of saturated fat. Ultimately, this could increase your cholesterol and increase your risk of developing heart disease. In addition, following a very low-carb diet (less than 50g), otherwise known as the keto diet, can result in a build-up of ketones in the blood, which can lead to ketosis – this can cause dizziness, sickness, headaches and dehydration. Finally, a low carb diet can result in a lack of energy during exercise (your muscles rely on carbs as their main source of fuel), which could prevent you from achieving your 150 mins of moderate activity a week – unhelpful if weight loss is your goal!
The conclusion? Your diet doesn’t need to be restrictive for you to lose weight. Yes, there is a case for reducing processed and sugary carbohydrates in your diet, but the healthier sources such as wholegrains, fruit, vegetables and pulses are in fact integral to a healthy, balanced diet. Remember, the best dietary pattern for you is one that meets your needs, is sustainable and – most importantly – is one that you enjoy. During the current Covid-19 pandemic, the best dietary pattern will also be dependent on what you are able to buy or source – and that’s okay. Hopefully this article will have reassured you that carbs can be included in your diet during this time – and, indeed, at any time! If you’d like support during this time, we are still open for business – sign up here.
Read some other blogs in our Myth Busting Series:
Wk1 Can you trust what you read online?
Wk2 Calories: Should you focus on quantity or quality?
Wk3 Should you be cutting carbs for weight loss?
Wk4 Should you be following a low fat diet?
Wk5 Protein: What sources are there?