The Science of Keto: How the Diet Facilitates Weight Loss


The keto diet has proven to be an incredibly popular way to lose weight, but how does it work? And what do you have to do to apply this diet to your life and use it to drop those excess pounds finally?

In this guide, we’ll explore the medical science behind the ketogenic diet to explain how it helps you lose weight and outline the steps you will need to take to achieve your weight loss goals with keto. 

How Does the Keto Diet Work? A Simple Overview

To understand how the keto diet works, we must understand the critical differences between fats and carbohydrates and how our body processes each.

Carbohydrates and the Western Diet

Carbohydrates -or carbs, if you prefer- are sugar molecules, one of the three primary macronutrients (along with protein and fat) in the typical Western diet. 

A standard diet for an American adult contains as much as 50% carbs, some 42% of which are “low-quality carbs” that provide minimal nutrients and contribute to weight gain. 

When we follow this Western diet, our bodies take these carbohydrates and convert them into a form of sugar known as glucose

This glucose gets absorbed by the small intestine and the stomach before releasing it into the bloodstream, where it can be used to give us the energy we need for our physical activities.

If we don’t burn enough energy throughout the day, that glucose stays in our system, stored for later use as body fat.

The energy provided by any given piece of food or drink is measured in calories, so the only way to take off the pounds and keep them off is to burn off more calories (i.e., use more energy) than we consume. 

This is where we get the famous mantra that the best way to lose weight is to “eat less and move more.” 

Keto Di”t and the Role of Fat 

keto dietary fat

Eating less is one of the main reasons why the keto diet works. Compared to a regular diet, eating keto means you feel full much quicker and stay full much longer, meaning you’re not hungry throughout the day and thus don’t eat as much. 

That’s notThat’shat happens. 

When you follow the keto diet, the idea is that you severely restrict the amount of carbohydrates you consume, ensuring that they account for no more than 10% of your daily intake. 

Adopting this method means our bodies can’t rely on carbs to produce enough glucose, so they must use fat as an alternative primary fuel source. 

This alternative is stored fat, which gets broken down by the liver and converted into chemicals called ketones.

This process is known as ketosis, from which we get the name for the keto diet.

Since it’s typically stored fat that makes us overweight in the first place, burning it for energy is a much more efficient way of losing weight. 

How to Make the Keto Diet Work For You 

So, now you understand what’s going into your body when you adapt to the ketone diet; the next big question is, what do you need to do to make it happen?

Ultimately, it all boils down to paying close attention to those three essential macronutrients, carbs, fats, and proteins, and how much of each you consume. 

In simple terms, you want to follow a 10/70/20 ratio as follows: 

1. Carbohydrates – 10% of Your Daily Intake 

Some people mistakenly believe that carbs are only found in unhealthy foods, such as processed foods, cookies, candy, desserts, chips, and soda.

However, they can also be found in foods that most people consider healthy, such as fruits, certain vegetables, and whole grains. 

With that in mind, your first step towards successfully making the keto diet work for you is significantly reducing how much of these foods you eat. 

If the typical American diet contains 50% carbs, that means cutting out 40% and limiting yourself to a few small carb-based foods daily. 

2. Fats – 70% of Your Daily Intake 

If you only ate a small helping of carbs daily and nothing else, you’d become ill sooner or later. Hence, you need to get nutrients, vitamins, and minerals from somewhere and give your body an alternative energy source.

How do you do that? 

You can do so by replacing most of your carbs with fats that can be broken down to create the state of ketosis. 

Although you might see this as giving you carte blanche to consume as many bacon sandwiches and cheeseburgers as you’d like, normal rules of healthy eating still apply, and these foods should be kept to a minimum to protect yourself from heart disease and certain types of cancer. 

Instead, you can get all the fats you need from fresh meats and poultry, including beef, pork, and chicken, which contain little to no carbs.

3. Protein – 20% of Your Daily Intake 

Proteins are found in fresh meats, eggs, fish, other animal products, and vegan alternatives. They are a vital macronutrient as they help you maintain healthy muscles and bones and work to keep your skin healthy, and promote a healthy digestive system. 

However, it’s known that too much protein in your system can prevent – or at least significantly limit – your body’s ability to produce ketones.

While the inverse carb/fat intake makes the keto diet work, paying attention to how much protein you consume is just as important. 

In other words, if your protein intake is more than 20%, the keto diet isn’t going to work as effectively for you. 

If you’re struggling to get these macros just right, you can use tools like Keto Calculators to help you out. Keto meal plans can also be found across the Internet and are designed to ensure you get the right amount of carbs, fats, and proteins daily. 

How Long Does it Take Keto to Work? 

Most people who start a ketogenic diet want to see results as fast as possible, and who could blame them?

The good news is that you typically don’t have to wait too long. 

If you follow the instructions above, your body should start getting into ketosis by the end of the first week. Most people then begin to see noticeable changes to their weight within 10 – 14 days, though sometimes it can take as long as three weeks to see such changes. 

To learn more about this, check out our guide titled How Long Does it Take to Get into Ketosis?

How to Tell if the Keto Diet is Working: A Final Piece of Advice 

They say that patience is a virtue, and that’s certainly true when it comes to making the keto diet work for you. 

To achieve weight loss success, you should stick with this diet for at least 2 – 4 weeks to ensure your body is fully adapted to burning energy from fats. 

Still, we understand that this can feel like a long time, especially when you’re on a diet that some people find restrictive.

Fortunately, you don’t have to fumble around in the dark for a month wondering if what you’re doing is working, as there are multiple ways to tell if your body is in a state of ketosis. 

Apart from the most obvious one (you lose weight), you may also notice changes in the smell of your breath or urine or note that you feel thirstier than usual as the added ketones flush water out of your system much more rapidly.

If you’re still unsure, you can buy tests like these Perfect Keto Ketone Testing Strips, which can tell you in a matter of minutes whether or not you’re in yours. 

To learn more about how to use the keto diet and determine whether it’s the right move for you, see our complete beginner’s guide to the keto diet.