What Happens When You Cut Carbs from Your Diet?

Inarguably, the word “carbs’ has become a taboo in the ‘weight -loss world’ and also a topic for hot debate.

The advent of the keto-diet, Atkins diet, and other “ low carb diets” can make you question the health benefits of carbs in our body and even label carbs as “bad”.

Carbohydrates have a broad category and not all carbs are bad. The quality, quantity, and type of carbs found in our diet are really of great essence.

So, what are Carbs?

Basically, carbs are one of the three macronutrients that form a major part of our diet. Other macronutrients are protein and fats. All these macronutrients provide the body with energy usually measured in calories.

There are basically 3 types of carbs found in food and they are:

  1. Refined Carbs: commonly referred to as sugars. They are carbs that have had all fiber and major nutrients stripped of them during processing. They are sometimes referred to as empty calories or added sugars. They are easily digested and have a high tendency to spike blood sugar. Examples include some breakfast cereals, white flour, pastries, snacks, sodas.
  2. Dietary Fibres: found in plant sources of carbohydrates majorly. Their major function in the body is to aid easy digestion and also control glucose spikes. Examples include vegetables, fruits, and whole grains. Dietary fiber has been linked to a reduced risk of type 2 diabetes, heart diseases, and colorectal cancer.
  3. Starch:  also found in plants and slowly release energy to the body throughout the day. Examples include potatoes, yam, plantain, whole wheat or white bread, brown or white rice. These foods also contain varying amounts of dietary fiber which could provide extra health benefits.

Can Carbs make you Fat?

Any type of food can make you fat when eaten in excess. Protein, fat, or carbs, when taken in quantities above daily requirement will result in weight gain over a long period of time.

When compared with fat, carbs contain fewer calories (1g of carbohydrate gives 4kcal while 1g of fat gives 9kcal of energy). This is why a high intake of both carbs and fat will definitely result in weight gain.

Also, Refined carbs are less satisfying than whole grains and vegetables and you may need a large portion size to feel full, this will lead to a high intake of calories and weight gain.

Why do I lose weight when I cut Carbs?

1. You shed water weight

It’s true that weight loss is rapid when carbs are cut out but are you really burning fat during this process?

What really happens when we eat carbs in excess is that there is water retention. Yes! Water retention!

Basically, carbs are stored in your liver and muscles as glycogen, which is your body’s preferred energy; each gram of glycogen stored holds 3g of water with it. So invariably, 1g of carbs, is stored in the liver and muscles alongside 3g of water.

Ideally, for an individual on a 2000 calorie diet, the daily value for carb intake is 250g (this is at 50% of dietary intake) inclusive of whole grains, fruits, and vegetables. Anything above that amount daily may lead to retention of water thereby causing water weight.

Highly refined carbs have a lot of added/refined carbs and salt in them, thereby making water retain more in tissues around your cells.

When you cut out carbs and you lose weight rapidly, you have just lost water weight. Your body doesn’t store glycogen anymore but draws from its body stores thereby reducing water. Ever noticed that if you add back those carbs, you put on weight again so fast? This is because the process involved in a very low carb-diet approach to losing weight is a reversible one.

When carbs are cut out, the body depends solely on fat and protein for energy, thereby exposing the body to harm from saturated fats and limiting protein in other important bodily functions.

With low levels of glucose in the body, the body breaks down stored fat and converts it into energy; this process further leads to a buildup of ketones in the blood which leads to ketosis.

Ketosis could cause headaches, weakness, dehydration, irritability, and dizziness.

2. You’re on a Calorie deficit diet

ideally, a deficit of 500 calories per day would lead to a 0.5kg drop in weight in a week. If you cut carbs from your diet and take only fruits and vegetables (which are still carbs though), and probably some animal sources of protein, you will experience extreme weight loss due to the calorie deficit. This type of weight loss is however not sustainable as you are also losing your muscle and bone mass within a short period of time, this will result in a drop in your metabolic rate (the rate at which you burn food) and consequently weight gain once you get back on your regular diet.


What’s the best approach to Weight-loss?

Sustainability is very important when trying to shed some pounds or when adopting a “diet”.

The best approach is to adopt a lifestyle that suits you. Calorie deficits, exercise regimes, and lifestyle modifications all go hand in hand to help lead a healthy lifestyle.

The weight loss approach should not be ‘all or nothing’,  strict, rigid, or a quick fix. It should be what you can live with over a very long period of time. It is also very important to note that the psychological effects of ‘dieting” could have a great impact on health.

The best approach is to limit intake of refined/ processed foods, focus more on whole grains, fruits, vegetables, pulses, and nuts and be active.


If you intend to lose weight, you don’t have to cut out carbs completely out of your diet. The quality, quantity, and type of carbs matter a lot. Need support on your weight loss journey?  Speak with a dietitian and join our Khairo Diet Lifestyle Community!









Consult a Dietitian

Dietary Counselling, Meal Plan, Medical Nutrition Therapy, And many more.

How do you know the best diet for weight loss?

Get this free ebook to find out!

Why is it so Hard to Lose Weight? by Osunsanya Olajumoke RDN, MPH