Calculating Calories For Ketosis: A Keto Guide

The ketogenic diet is a high-fat, low-carb approach to eating that aims to force the body to burn fat for fuel instead of carbohydrates. To achieve this state, known as ketosis, it's important to calculate your macronutrient intake, or macros, to ensure you're eating the right amount of calories from fat, protein, and carbohydrates. This involves determining your Basal Metabolic Rate (BMR), or the number of calories your body burns at rest, and your Total Daily Energy Expenditure (TDEE), which includes physical activity. Using a keto calculator, you can input your gender, age, height, weight, body fat percentage, and activity level to establish your BMR and TDEE, and ultimately determine your ideal calorie and macronutrient intake for ketosis.

Calculate your Basal Metabolic Rate (BMR)

To calculate your Basal Metabolic Rate (BMR), you can use either direct or indirect calorimetry, or a mathematical equation. Direct calorimetry is the most accurate method, but it is usually only available in research settings. It involves spending time in a tightly controlled room, known as a calorimeter, with little to no movement. Indirect calorimetry involves using an in-office device to measure the exchange of oxygen and carbon dioxide in your body.

If you don't have access to these methods, you can use a mathematical equation to estimate your BMR. The Mifflin-St. Jeor equation is a popular way to do this. This equation calculates your resting metabolic rate (RMR), which is slightly different from BMR. Your RMR is the number of calories you burn with minimal movement, whereas BMR measures the calories burned with zero movement. However, these terms are often used interchangeably, and your RMR should give you a good estimate of your BMR.

The Mifflin-St. Jeor equation for men is:

BMR = 10 × weight (in kilograms) + 6.25 × height (in centimeters) – 5 × age (in years) + 5

And for women:

BMR = 10 × weight (in kilograms) + 6.25 × height (in centimeters) – 5 × age (in years) – 161

For example, a 35-year-old man who weighs 200 pounds (90.7 kg) and is 6 feet tall (183 cm) would have a BMR/RMR of 1,882. This means he will burn around 1,882 calories per day at rest.

A 35-year-old woman who weighs 150 pounds (68 kg) and is 5 feet 7 inches tall (170 cm) will burn around 1,409 calories per day at rest.

It's important to note that your BMR is not the total number of calories your body needs per day. It only represents the calories your body needs at rest. To calculate your total daily calorie needs, you need to multiply your BMR by an activity factor.

Your BMR is influenced by various factors, including age, weight, height, gender, environmental temperature, dieting habits, and exercise habits. Keep in mind that your BMR is not a perfect indicator of your health. While a higher BMR can indicate a larger body, more muscle mass, or genetics that favour a faster metabolism, it does not necessarily mean you are healthier than someone with a lower BMR.

Determine your Total Daily Energy Expenditure (TDEE)

To calculate your Total Daily Energy Expenditure (TDEE), you need to establish your Basal Metabolic Rate (BMR) and then factor in your physical activity levels.

Your BMR is the number of calories your body burns when at rest. In other words, it's the amount of energy you spend per unit of time while doing absolutely nothing. This is calculated using your gender, age, height, and weight. There are several formulas for determining BMR, with the Mifflin-St Jeor equation being one of the most accurate.

Once you have your BMR, you need to consider your physical activity levels. This is measured as your Physical Activity Level (PAL) and indicates how much energy you spend daily when you're active. This can range from sedentary (little or no exercise) to athlete (hard exercise daily and/or a physical job).

The keto calculator then combines your BMR and your PAL to determine your TDEE, which is the number of calories your body burns in 24 hours. This figure is important because it tells you how many calories you need to eat daily to cover your energy expenditure.

It's important to note that your TDEE is not a static number and can change over time as your weight, activity levels, and body composition change. Therefore, it's a good idea to recalculate your TDEE periodically to ensure you're still on the right track.

Establish a calorie deficit or surplus

The number of calories you consume daily is a crucial factor in determining whether you will lose, gain, or maintain your weight. A calorie deficit will help you lose weight, while a calorie surplus will help you gain weight.

The keto calculator will help you determine your Basal Metabolic Rate (BMR), which is the amount of energy your body spends per unit of time while at rest. In other words, it's how many calories you burn by doing absolutely nothing. Your BMR is influenced by your gender, age, height, and weight. As a rule of thumb, the older you get, the more your muscle mass declines, resulting in a lower BMR.

To establish a calorie deficit or surplus, you can use the keto calculator to input your details and specify whether you want to maintain, lose, or gain weight. The calculator will then suggest a calorie intake goal for you. For instance, if you opt for a 10% calorie deficit, your total daily calories will be reduced by 10%, facilitating moderate weight loss. Conversely, setting a 10% calorie surplus will increase your daily calories by 10%, aiding in weight gain.

It's important to note that the number of calories you consume is not the sole factor in weight management. The quality of your food choices also plays a significant role. Opting for whole foods rich in vitamins and minerals is generally recommended over processed foods, which often contain harmful ingredients. Additionally, the thermic effect of different macronutrients varies, with protein requiring more calories to be burned during digestion compared to carbohydrates.

To summarise, establishing a calorie deficit or surplus is a fundamental aspect of the keto diet. Utilise the keto calculator to determine your personalised calorie intake goal, taking into account your unique characteristics and weight goals. Remember to also prioritise high-quality food choices to support your overall health and well-being.

Adjust your protein intake

Protein is the building block of human muscle mass. Eating too little protein may cause a loss of muscle mass, while eating too much can lead to the body converting the excess to glycogen (carbohydrates), potentially pushing you out of ketosis. Therefore, it is important to adjust your protein intake to suit your body composition and activity level.

It is recommended that you start with a protein intake of 0.8 grams of protein per pound of lean body mass. This can be calculated by first determining your body fat percentage, and then subtracting this from your total body weight. For example, if you weigh 150 pounds and have a body fat percentage of 20%, your lean body mass is 120 pounds.

If you lift weights or engage in intense physical activity, you may need to increase your protein intake to support muscle growth and repair. On the other hand, if you are sedentary or have a less active lifestyle, you may need to reduce your protein intake to avoid disrupting ketosis.

It is worth noting that protein intake is not the only factor that affects ketosis. The total amount of carbohydrates and fat intake also play a crucial role in achieving and maintaining ketosis. Therefore, it is important to consider your overall calorie intake and macronutrient ratios when adjusting your protein intake.

Additionally, it is recommended to use a keto calculator to determine your specific protein needs based on your body composition, activity level, and goals. These calculators take into account various factors, such as age, gender, weight, and body fat percentage, to provide personalized recommendations.

By adjusting your protein intake based on your individual needs and activity level, you can optimize your keto diet and work towards achieving your health and fitness goals.

Track your macros

Tracking your macros is essential to staying in ketosis and becoming more aware of the macronutrient content of your food. It is also a good way to ensure that you are following a keto meal plan that works for you.

To track your macros, you will need to calculate your basal metabolic rate (BMR), which is the amount of energy you spend per unit of time while resting. In other words, it is how much energy you burn by doing absolutely nothing. Your BMR will depend on your gender, age, height, and weight. For instance, as muscle mass lowers, so does your BMR.

Once you have calculated your BMR, you can determine your total daily energy expenditure (TDEE), which is the number of calories your body burns in 24 hours. Your TDEE will tell you how many calories you need to eat daily to cover your energy expenditure. You can then decide whether you want to maintain, lose, or gain weight by picking a calorie deficit or surplus.

For example, if you want to maintain your weight, keep the bar at 0%. If you want to lose weight, move the bar between 0 and -50 (calorie deficit). Stay within 10-20% for moderate weight loss. If you want to gain weight, move the bar between 0 and +50 (calorie surplus). Again, stay within 10-20% for moderate weight gain.

You can also calculate your body fat percentage to determine your lean body mass and get a more accurate estimation of your TDEE. This will help you figure out how many calories you need from protein per day to lose weight without reducing your muscle mass.

To track your macros, you can use a keto calculator, such as the ones provided by Ketogenic.com, Keto Karma, Keto Mojo, or Keto Connect. These will ask for your personal information, such as gender, age, height, weight, and body fat percentage, and then calculate your BMR and TDEE for you.

You can also track your macros by keeping a food journal, either by hand or using an app like Cronometer or MyFitnessPal.

Frequently asked questions