If you have an interest in nutrition or you’re looking for new ways to lose weight, you may have stumbled across the term "ketogenic (keto) diet." Keto diets are trending at the moment, and there’s a growing interest in this form of health and weight loss, but how does it work and what actually happens to your body in the first few days?

A brief guide to the keto diet

A keto diet is designed to change your primary fuel. In the most basic terms, the aim of the diet is to encourage your body to look for alternative sources of fuel, rather than relying on glucose. With a traditional diet, your body converts foods that contain carbohydrate into glucose, which gives you energy. On a ketogenic diet, you cut down your carbohydrate consumption, and this prompts the body to search for other sources of fuel. Rather than depending on glucose, the body starts to process and burn ketones. A ketogenic diet involves increasing your intake of fats and decreasing your intake of carbohydrates.

What happens to your body when you start a ketogenic diet?

When you change your diet, your body is likely to react. If you’re not used to a high-fat diet, and you’ve been reliant on glucose for energy for your entire life, it’s natural for your body to go through a period of transition. The key is not to focus on how you feel in the first few days, but to concentrate on the future and the long-term benefits of altering your diet and losing weight. If you’re thinking about trying out a keto diet, and you’re keen to learn more, here are some of the changes you can expect to experience during the first few days.


When you first start the ketogenic diet, it’s common to experience tiredness. This is because your body is still programmed to look for fuel from carbohydrates, even though you’ve cut your intake. The first stage is often hard because your body is adapting to the change, and you might feel slightly sluggish. As your body adjusts, you’ll find that you feel more energetic and alert. If you are drowsy, and you feel like you’ve got no get up and go, you may benefit from taking supplements like KetoCaNa Orange in the first few days.

Decreased hunger

Ketogenic diets are known to suppress hunger and reduce your appetite. When you start the diet, you’ll increase your intake of proteins and foods that are rich in healthy fats, which will make you feel fuller for longer.

Headaches and nausea

When you change from using glucose to burning ketones, it’s common to notice side-effects, some of which can be unpleasant. As your digestive system responds to modifications in your diet, you may find that you develop nausea and headaches. As you enter into a state of ketosis, and your body becomes accustomed to your new diet, you should find that side-effects subside.


The ketogenic diet can increase the risk of constipation, as it may decrease your intake of fiber. Fiber is an essential component of a balanced diet, and it facilitates effective, efficient digestion.

Bad breath

Bad breath is caused by the production of a ketone known as acetone, which is released by the liver. If you follow a ketogenic diet, you might find that you are more prone to bad breath.

Adjusting to the ketogenic diet

Starting a new diet of any kind is likely to result in side-effects. The ketogenic diet represents a major shift in terms of the foods you eat and the way your body produces and uses energy, so it’s natural to experience a reaction. Although many of the immediate effects are unpleasant, they will subside once your body gets used to your new diet. Side-effects tend to be short-lived, and once you’re in the swing of things, you should notice the weight loss and wellbeing benefits. 

It seems as though everyone is talking about the ketogenic diet. If you’re looking at ways to improve your health by altering your diet, hopefully, this guide has given you insight into what you can expect when you start your new diet. Side-effects are common, but they don’t last long, and they tend to be mild. If you can get through the first few days, you’ll find the weeks and months that follow much easier. The keys are preparation and patience!

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