Metabolism is your body’s engine, converting food into energy to support everything from basic functions to intense workouts. During a 90-day transformation, understanding how to use metabolism effectively can mean the difference between hitting a plateau and achieving remarkable results. While diet dictates weight loss or muscle gain, metabolism is your unique energy fingerprint, accounting for the second-largest share of your daily calorie burn. By starting with estimates and making adjustments based on progress, you can optimize fat loss and muscle growth.
What Is Metabolism and Why Does It Matter?
Metabolism is the sum of all chemical processes that keep your body running. It includes:
- Basal Metabolic Rate (BMR): The energy your body uses at rest.
- Non-Exercise Activity Thermogenesis (NEAT): Calories burned through daily activities like walking, standing, or fidgeting.
- Exercise Activity Thermogenesis (EAT): Calories burned during intentional workouts.
- Thermic Effect of Food (TEF): Energy used to digest and process food.
Your metabolism is unique, influenced by age, gender, muscle mass, and genetics. However, it can be measured and adjusted based on how your body responds to diet and exercise.
How Do You Calculate Your Starting Metabolism?
To use metabolism for a 90-day transformation, start by estimating your daily calorie needs using online calculators like the Mifflin-St Jeor Equation for BMR:
- Men: (10 × weight in kg) + (6.25 × height in cm) – (5 × age) + 5
- Women: (10 × weight in kg) + (6.25 × height in cm) – (5 × age) – 161
Multiply BMR by an activity factor to get Total Daily Energy Expenditure (TDEE):
- Sedentary (little or no exercise): BMR × 1.2
- Light activity (1-3 days/week): BMR × 1.375
- Moderate activity (3-5 days/week): BMR × 1.55
- Very active (6-7 days/week): BMR × 1.725
- Super active (athlete-level training): BMR × 1.9
This gives a baseline calorie target, but the key is adjusting based on actual results.
How Do You Adjust Metabolism for Fat Loss?
If fat loss is the goal, you need a calorie deficit where intake is lower than calories burned. Typically, a 500-750 calorie deficit per day results in a 1-1.5 pound loss per week. However, metabolism adapts over time, requiring adjustments:
- Track Progress: If weight loss slows after 2-3 weeks, metabolism may have decreased. Reduce calories by 100-200 or increase NEAT through extra steps.
- Monitor Energy Levels: If fatigue increases, metabolism may be slowing too much. Ensure protein intake remains high (0.8-1g per pound of body weight) to preserve muscle.
- Adjust Based on Feedback: If weight loss is faster than expected (more than 2 pounds per week), metabolism may still be high. Consider adding calories to prevent muscle loss.
How Do You Adjust Metabolism for Muscle Growth?
To build muscle, a calorie surplus is needed. Aiming for a 250-500 calorie surplus daily can result in a 0.5-1 pound gain per week, but metabolism plays a role:
- Increase Calories Slowly: If weight isn’t increasing after two weeks, add 100-200 calories, focusing on protein and carbs.
- Look for Performance Improvements: Strength gains in the gym indicate an active metabolism supporting muscle growth.
- Watch for Fat Gain: If body fat increases too quickly, metabolism might not be using all the extra calories efficiently. Reduce the surplus slightly.
How Do Diet and Exercise Influence Metabolism?
Metabolism is dynamic and influenced by your choices:
- High-Protein Diet: Protein has the highest TEF, requiring more energy for digestion and supporting muscle retention.
- Strength Training: Muscle mass increases BMR, meaning you burn more calories at rest.
- Cardio and NEAT: Moderate-intensity cardio and daily movement prevent metabolism from slowing during a fat loss phase.
By making small, calculated adjustments, you can keep metabolism working in your favor throughout the 90-day transformation.
Key Takeaways
- Metabolism accounts for the second-largest share of calorie burn after diet.
- Start with calculated estimates (BMR and TDEE) but adjust based on results.
- Use a deficit for fat loss and a surplus for muscle growth, making small changes as needed.
- Monitor energy, weight changes, and performance to ensure metabolism is optimized.
- Diet, strength training, and NEAT all influence metabolic rate.
A successful 90-day transformation relies on understanding and adapting to your metabolism. By tracking progress and making informed adjustments, you can ensure steady fat loss or muscle growth, leading to long-term success.
Read Next…
- Harness Your Metabolism for a 90-Day Transformation
- 10 Things That Prevent You From Staying Consistent on a Health and Fitness Journey
- What to Expect When You Do a Check-In With a Health Coach
- How to Check Progress on a Health and Fitness Journey to Reach Goals Faster
- When to Count Calories on a Health and Fitness Journey
