• Shannon Western

What Happens If You Cut Carbs?

Carbohydrates have been in the firing line for some time now. You have probably heard carbohydrates being criticised in the media, by friends, family, and as the punchline of jokes in TV shows. But carbohydrates are essential for making sure our bodies have enough energy to get through the day and even lower the risk of some diseases.

I know it can be hard to change your mindset about foods you’ve always been told aren’t great for you; after all carbs are 99% of my clients top “bad foods”!

Carbohydrates are demonised in a lot of circles in our lives. This might be anywhere from the mega-fad diets such as Atkins or the new ketogenic diet, to the ‘gym bro’ who is counting all his macros. They are also made out to be the enemy when people make ‘healthy changes’ which see people swapping rice for courgetti. This isn’t necessary because we need that rice to bulk up our plate in a fulfilling and still nutritious way!

So we can see there is demonising carbs to the extreme with the Atkins diet. Then there are people in between using Keto as their ‘diet’ method. And finally we have wellness culture, which tells us to think healthier and swap our much needed carbs for low-carb options instead.

What is a carbohydrate?

When you really think about it, do you really know what carbohydrates even are!?

I got you….

Carbohydrates are one of the three macronutrients our body needs in “large” quantities each day i.e., grams. Compared to micronutrients, which we need in smaller amounts i.e., milligrams or micrograms.

There are different types of carbs, including:

Starch aka complex carbohydrates.


  • Provide vitamins and minerals, such as vitamin B and iron, to our bodies.

  • They are typically responsible for keeping blood sugar levels stable, while making us feel full and satisfied.

Examples of starchy carbs are:

  • Legumes like chickpeas, lentils, kidney beans

  • Grains like rice, quinoa, barely, and bread products

  • Nuts and seeds

  • Fruit like apples, pears, berries, dried fruit

  • Vegetables like corn, broccoli, onions

Fibre - another complex carbohydrate

Plant based foods are typically our main source of these in the diet.

Fibre also regulates blood sugar levels, lowers LDL cholesterol levels in the blood, and similarly to starch (1).

Some foods we can get fibre in include…

  • Beans like black, pinto

  • Vegetables like broccoli and carrots

  • Fruit, especially with edible skin such as apples and pears

  • Nuts like almonds and peanuts

  • Grains like rice and quinoa

Sugar - a “simple” carbohydrate

This carb is a type of simple carbohydrate which is broken down quickly by our body.

Sugar breaks down quicker than other carbohydrates, which is why there might be an increase in the amount of sugar levels in our blood. However, this only happens when sugar is eaten in isolation - I don’t know about you, but people don’t often eat tablespoons of sugar straight off a spoon?

Sugar has so many different names, but they all provide the body with a quick boost of energy.

  • Agave nectar

  • Corn syrup

  • Honey

  • Molasses

  • Sucrose

  • Fructose

  • Coconut sugar

  • Maple syrup

Why do we need carbs?

1. Energy – Carbs should be our bodies main source of energy. They are essential to fuel not only exercise and activity, but literally just for your body to function i.e., to breathe and digest food! You still need an adequate amount of carbohydrates even if you lie in bed all day.

2. Disease risk – carbs in the form of fibre are important for bowel health. They will help reduce the risk of constipation, and some forms of fibre have even shown to reduce cholesterol levels (1).

Research shows diets high in fibre are linked to a lower risk of cardiovascular disease, type 2 diabetes and bowel cancer (1).

3. PCOS & Diabetes prevention – Whole Grain carbs such as oats have shown amazing results in studies in preventing type 2 diabetes and insulin resistance (2). One also showed more consumption of wholegrains was able to reduce the risk of developing PCOS by 64% (3).

4. Maintain menstrual cycles – in those who menstruate, cutting carbs from your diet for too long can cause irregular cycles or even missing cycles. This is known as amenorrhea (4).

5. Serotonin production - As 95% of our bodies serotonin is made in the gut (5) fibre is vital for serotonin production. This means limiting carbs can have a negative effect on our mood because of the limited serotonin being produced in our gut.

Myth busting

As I mentioned at the start of the blog, carbohydrates have been framed as a villain of the ‘diet’ world. So I thought it might be a good idea to talk through some of these common beliefs about carbohydrates.

Carbs make you gain weight

No one food makes you gain or lose weight.

And I’m a weight neutral nutritionist - so I don’t promote weight gain as a bad thing, ever. No matter the situation, person, etc.

Does eating “too many” of any food cause weight gain? Maybe, maybe not!

Calories in vs calories out is a really outdated formula that doesn’t really hold weight (pardon the pun…) in real life.

While it’s true that cutting carbs can cause weight loss, it's only temporary. It’s water weight! This is because storage carbohydrates are used up which are stored alongside water.

Low carb diets are healthier

If you cut out carbs from your diet, that initial water weight is lost.

However, this method of weight loss is dangerous and comes with some potentially damaging side effects. This could be related to low fibre intake which has an effect on our mood due to reduced serotonin production, mental health impacts from food restriction, and many more - check out my article about The Minnesota Starvation Experiment which gives a big insight into the negative impact of dieting.

Carbs make you sluggish