How Does the Keto Diet Work?

Introduction

The ketogenic diet is all about playing the metabolic game smartly.

By reducing carbs and upping healthy fats, you trigger ketosis, where your body rocks on ketones for energy instead of glucose. This can boost your energy and may help with shedding some pounds. But here’s the deal: it’s vital to know your caloric needs and metabolic rate.

Everyone is unique, and what works for one might not for another. Understanding your body’s requirements ensures you play the keto game safely and effectively.

In this easy-to-understand guide, we’ll explore the fascinating science behind the keto diet and uncover how it can transform your body’s metabolism.

Forget complicated jargon – I’ll break it down for you step by step. By the end, you’ll have a clear picture of what ketosis is, the potential benefits it offers, and the things you should keep in mind before hopping on the keto bandwagon.

Let’s dive in and discover the secrets of this popular diet trend!

Understanding the Keto Diet

So… How does the keto diet work…?

The keto diet is a low-carbohydrate, high-fat diet that aims to shift the body into a metabolic state called ketosis.

Normally, our bodies primarily rely on carbohydrates as the main source of energy. However, by significantly reducing carbohydrate intake and increasing fat consumption, the keto diet prompts the body to utilize fat as its primary fuel source instead.

How Ketosis Works:

When carbohydrate intake is restricted, the body’s glycogen stores become depleted. As a result, insulin levels drop, and the body turns to alternative energy sources.

Fatty acids are released from fat stores and transported to the liver, where they are converted into ketones—a byproduct of fat metabolism.

These ketones then serve as an energy source for the body, including the brain, which typically relies on glucose for fuel.

Benefits of the Keto Diet:

Weight Loss: The keto diet may aid weight loss by increasing satiety, reducing appetite, and promoting fat burning due to the higher fat content and lower carbohydrate intake.
Improved Insulin Sensitivity: The keto diet may help improve insulin sensitivity and blood sugar control, making it beneficial for individuals with type 2 diabetes or prediabetes.
Increased Mental Clarity: Some individuals report improved focus and mental clarity while following the keto diet, likely due to the brain’s utilization of ketones as an energy source.

In total, there are four recognized types of Ketogenic Diet.

They vary with respect to each other based on the personal weight goals of the individual. Someone wishing to incorporate a keto diet with a vigorous excercise regime will have very different calorie needs to another who’s daily excercise amounts to walking the dog twice a day.

Standard Ketogenic Diet (SKD):

On a standard ketogenic diet (SKD), the macronutrient ratios are typically adjusted to induce a state of ketosis. The main principle of a SKD is to significantly reduce carbohydrate intake, increase fat intake, and consume a moderate amount of protein. Here are the recommended macronutrient ratios for a SKD:

Carbohydrates: Usually limited to around 5-10% of total calories.
Protein: Moderate intake, typically around 20-25% of total calories.
Fat: High intake, typically around 70-75% of total calories.

Working Example

Female

Adjust the BMR calories based on the standard ketogenic diet ratios:

BMR ≈ 1409.268 calories per day

Fat calories = 1409.268 x 0.70 ≈ 986.49 calories (70%)

Protein calories = 1409.268 x 0.25 ≈ 352.32 calories (25%)

Carb calories = 1409.268 x 0.05 ≈ 70.46 calories (5%)

Male

Adjust the BMR calories based on the standard ketogenic diet ratios:

BMR ≈ 1825.787 calories per day

Fat calories = 1825.787 x 0.70 ≈ 1278.05 calories (70%)

Protein calories = 1825.787 x 0.25 ≈ 456.45 calories (25%)

Carb calories = 1825.787 x 0.05 ≈ 91.29 calories (5%)

Targeted Ketogenic Diet (TKD):

Carbohydrates: Around 5-10% of total calories.
Protein: Moderate intake, typically around 20-25% of total calories.
Fat: High intake, typically around 70-75% of total calories.
Additionally, a small amount of carbohydrates can be consumed before or after workouts to provide energy for exercise.

Cyclical Ketogenic Diet (CKD):

Carbohydrates: On carb-loading days, carbohydrate intake is increased to around 50-75% of total calories.
Protein: Moderate intake, typically around 20-25% of total calories.
Fat: High intake, typically around 5-10% of total calories.
CKD involves cycling between periods of ketogenic eating and higher carbohydrate intake, usually following a 5:2 or 6:1 ratio, where 5 or 6 days are ketogenic and 1 day is a high-carb day.

High-Protein Ketogenic Diet:

Carbohydrates: Around 5-10% of total calories.
Protein: Increased intake, typically around 30% of total calories.
Fat: Moderate intake, typically around 60-65% of total calories.
This variation of the ketogenic diet emphasizes a higher protein intake while maintaining low carbohydrate consumption.

CALCULATING BASAL METABOLIC RATE

Like any dieting program, before you begin, it’s essential to know where you are now. This begins with knowing your personal daily calorie needs – a benchmark that determines how much food you need to eat daily just to maintain your current weight and health.

Your daily calorific needs are commonly referred to as your BMR, or Basal Metabolic Rate.

Base Metabolic Rate

The Harris-Benedict equation is a widely used formula for estimating basal metabolic rate (BMR), which represents the number of calories your body needs to maintain basic physiological functions at rest.

The equation takes into account factors such as age, gender, weight, and height.

Because the BMR obtained using the Harris-Benedict equation is an estimation and may vary from person to person, other factors, such as physical activity level, body composition, and metabolism, should be considered when determining daily caloric needs.

Consequently, The ratios and values of macronutrients (carbohydrates, protein, and fat) can vary based on several factors such as age, gender, weight, height, and activity levels.

Let’s explore how these factors influence the macronutrient ratios and values:

Age

As people get older, their metabolism tends to slow down, resulting in a decrease in calorie requirements.
With age, the recommended calorie intake may decrease slightly to account for this change.
However, the macronutrient ratios generally remain relatively consistent.

Gender

Men and women have different calorie and macronutrient needs due to variations in body composition and hormonal differences.
Men usually require higher calorie intake and have higher protein requirements due to typically having more muscle mass.
Women may have slightly higher fat requirements for hormonal balance.

Weight

Body weight plays a crucial role in determining calorie and macronutrient needs.
Generally, individuals with higher body weight require more calories and macronutrients.
However, weight loss goals may lead to a reduction in overall calorie intake while maintaining adequate protein intake to support muscle mass.

Height

Height influences basal metabolic rate (BMR), which is the number of calories your body needs to perform essential functions at rest.
Taller individuals usually have a higher BMR, which means they require more calories to maintain their basic bodily functions.

Activity Levels

Physical activity levels have a significant impact on overall calorie requirements.
More active individuals typically need higher calorie intake to fuel their activities.
The macronutrient ratios may also shift slightly based on activity levels, with higher protein intake recommended for individuals engaged in strength training or intense exercise.

Adjust the BMR based on your activity level:

Sedentary (little to no exercise): BMR × 1.2
Lightly active (light exercise/sports 1-3 days per week): BMR × 1.375
Moderately active (moderate exercise/sports 3-5 days per week): BMR × 1.55
Very active (hard exercise/sports 6-7 days per week): BMR × 1.725
Extra active (very hard exercise/sports & physical job or 2x training): BMR × 1.9

Determine the caloric distribution for macronutrients:

Carbohydrates: 45-65% of total calories
Protein: 10-35% of total calories
Fat: 20-35% of total calories

Calculating Daily Calories

Calculate the calorie amounts for each macronutrient based on the percentages:

Carbohydrates (in grams): Total calories × carbohydrate percentage / 4
Protein (in grams): Total calories × protein percentage / 4
Fat (in grams): Total calories × fat percentage / 9

A working example

Female

BMR = 447.593 + (9.247 x weight in kg) + (3.098 x height in cm) – (4.330 x age in years)

Female (age 35) : Weight: 65 kg : Height: 165 cm

BMR ≈ 447.593 + (9.247 x 65) + (3.098 x 165) – (4.330 x 35)

BMR ≈ 447.593 + 601.455 + 511.77 – 151.55

BMR ≈ 1409.268 calories per day

Male

BMR = 88.362 + (13.397 x weight in kg) + (4.799 x height in cm) – (5.677 x age in years)

Male (age 35) : Weight: 80 kg : Height: 180 cm

BMR = 88.362 + (13.397 x 80) + (4.799 x 180) – (5.677 x 35)

BMR ≈ 88.362 + 1071.6 + 864.72 – 198.895

BMR ≈ 1825.787 calories per day

Open our Macro Calculator to get your personal daily Macro calculations…

Summary

The keto diet works by inducing ketosis, a metabolic state where the body relies on fat as its primary source of fuel instead of carbohydrates.

This shift in energy utilization has been associated with various health benefits, including weight loss, improved insulin sensitivity, and enhanced mental clarity.

When considering dietary needs, the Harris-Benedict equation provides a helpful estimation of basal metabolic rate (BMR). However, it’s important to consult with a healthcare professional or registered dietitian to customize a diet plan that suits your individual needs and goals.

Remember, while the keto diet may offer potential benefits, it may not be suitable for everyone, and long-term adherence should be approached with caution.

A well-rounded approach to nutrition, balanced macronutrient intake, and regular physical activity are key components of maintaining overall health and well-being.

It’s important to note again, that the specific macronutrient ratios and variations may vary depending on individual goals, preferences, and tolerances.

It’s recommended to consult with a healthcare professional or a registered dietitian to determine the most suitable macronutrient ratios for a specific type of ketogenic diet based on individual needs and health status.

Scientific References:

Paoli, A., Rubini, A., Volek, J. S., & Grimaldi, K. A. (2013). Beyond weight loss: a review of the therapeutic uses of very-low-carbohydrate (ketogenic) diets. European journal of clinical nutrition, 67(8), 789-796.
Kosinski, C., & Jornayvaz, F. R. (2017). Effects of ketogenic diets on cardiovascular risk factors: evidence from animal and human studies. Nutrients, 9(5), 517.
Masood, W., & Uppaluri, K. R. (2019). Ketogenic diet. Treasure Island (FL): StatPearls Publishing.
Mifflin, M. D., St Jeor, S. T., Hill, L. A., Scott, B. J., Daugherty, S. A., & Koh, Y. O. (1990). A new predictive equation for resting energy expenditure in healthy individuals. The American journal of clinical nutrition, 51(2), 241-247.

How Does the Keto Diet Work?

Introduction