Frequently Asked Questions
What is TDEE and why does it matter?
TDEE stands for Total Daily Energy Expenditure — it's the total number of calories your body burns in a day, including your Basal Metabolic Rate (BMR), physical activity, and the thermic effect of food. Knowing your TDEE is essential for any diet plan because it tells you exactly how many calories you need to maintain, lose, or gain weight.
What is the difference between Mifflin-St Jeor and Katch-McArdle?
Mifflin-St Jeor estimates BMR using age, gender, height, and weight. Katch-McArdle uses lean body mass instead, making it more accurate for people who know their body fat percentage — especially those with above-average muscle mass. If you know your body fat %, Katch-McArdle will often give a more personalized result.
How do I choose the right activity level?
Be honest about your actual daily movement. Sedentary means a desk job with no exercise. Light activity is 1-3 days of light exercise per week. Moderate is 3-5 days. Active is hard exercise 6-7 days. Very active is intense training plus a physical job. Athlete-level is for competitive athletes training multiple times per day. Most people overestimate their activity level.
How many calories should I eat to lose weight?
To lose weight, eat below your TDEE. A 500-calorie daily deficit results in about 1 pound of fat loss per week. Never go below your BMR for extended periods, and most men should stay above 1,500 calories while most women should stay above 1,200 calories to ensure adequate nutrition.
What macros should I eat for cutting vs bulking?
For cutting (fat loss), aim for higher protein (40% of calories) to preserve muscle, moderate carbs (35%), and lower fat (25%). For bulking (muscle gain), protein stays around 30%, carbs increase to 45% for training fuel, and fat is about 25%. For maintenance, a balanced 30/40/30 split of protein/carbs/fat works well for most people.
How accurate is a TDEE calculator?
TDEE calculators provide an estimate within about 10% of your actual expenditure. Factors like genetics, metabolic adaptation, NEAT (non-exercise activity thermogenesis), and hormones all play a role. Use the calculator as a starting point, track your weight for 2-4 weeks, and adjust by 100-200 calories if you're not seeing expected results.
Does body fat percentage affect TDEE?
Yes. Muscle tissue burns more calories at rest than fat tissue. Two people at the same weight but different body compositions will have different BMRs. The Katch-McArdle formula accounts for this by using lean body mass. If you have a higher muscle-to-fat ratio, your TDEE will be higher than standard formulas predict.
How often should I recalculate my TDEE?
Recalculate your TDEE every time you lose or gain 10+ pounds, change your activity level significantly, or every 8-12 weeks during a diet. As you lose weight, your TDEE decreases because your body has less mass to support. This is called metabolic adaptation and is a normal part of the process.