Question 1

How many calories should I eat per day to lose weight?

Accepted Answer

To lose weight safely, most experts recommend eating 300–500 calories below your Total Daily Energy Expenditure (TDEE). This creates a sustainable deficit that promotes 0.5–1 pound of fat loss per week. Use our calorie calculator to find your TDEE, then subtract 300–500 calories. For example, if your TDEE is 2,200 calories, aim for 1,700–1,900 calories per day. Never go below 1,200 (women) or 1,500 (men) without medical supervision.

Question 2

What is the difference between BMR and TDEE?

Accepted Answer

BMR (Basal Metabolic Rate) is the number of calories your body burns at complete rest — just to keep your organs functioning, breathe, and circulate blood. TDEE (Total Daily Energy Expenditure) is your BMR multiplied by an activity factor that accounts for exercise, walking, and daily movement. TDEE is always higher than BMR and represents the total calories you actually burn in a day.

Question 3

What is the Mifflin-St Jeor equation?

Accepted Answer

The Mifflin-St Jeor equation is considered the most accurate formula for estimating BMR in healthy adults. Published in 1990, it calculates: Men: BMR = (10 × weight in kg) + (6.25 × height in cm) – (5 × age) + 5. Women: BMR = (10 × weight in kg) + (6.25 × height in cm) – (5 × age) – 161. It is more accurate than the older Harris-Benedict equation, especially for overweight individuals.

Question 4

How many calories do I need to build muscle?

Accepted Answer

To build muscle, you need a calorie surplus of 200–400 calories above your TDEE, combined with adequate protein (0.7–1g per pound of body weight) and progressive resistance training. This approach — called "lean bulking" — minimizes fat gain while providing enough energy for muscle growth. Larger surpluses (500+ calories) lead to faster weight gain but significantly more of it will be stored as fat.

Question 5

Why am I not losing weight even though I'm eating fewer calories?

Accepted Answer

Several factors can stall weight loss despite calorie restriction: (1) Underestimating portion sizes and calories consumed; (2) Metabolic adaptation — your body lowers BMR during prolonged dieting; (3) Water retention masking fat loss; (4) Stress hormones (cortisol) promoting fat storage; (5) Insufficient sleep reducing metabolic rate. Try tracking calories precisely for a week, ensure adequate protein and sleep, and consider a brief "diet break" to reset metabolism.

Question 6

How do I count calories accurately?

Accepted Answer

For accurate calorie counting: use a digital food scale to weigh portions (don't rely on estimates), read nutrition labels carefully, track everything including cooking oils, dressings, and beverages, use a calorie tracking app like MyFitnessPal, and be consistent. Restaurant meals are notoriously hard to track — they typically contain 20–40% more calories than you'd expect.

Question 7

What are macronutrients and how should I split them?

Accepted Answer

Macronutrients are protein, carbohydrates, and fat — the three nutrients that provide calories. A balanced split for most adults is 25–35% protein, 35–45% carbs, and 25–35% fat. For weight loss, higher protein (30%+) helps preserve muscle mass and increase satiety. For athletic performance, higher carbs (45%+) fuel intense training. One gram of protein = 4 calories, carbs = 4 calories, fat = 9 calories.

Question 8

How many calories does exercise burn?

Accepted Answer

Calorie burn varies significantly by activity and intensity. Approximate calories burned per hour for a 155-lb person: walking (3.5 mph) burns ~300, running (6 mph) burns ~590, cycling (moderate) burns ~520, swimming burns ~440, weight training burns ~220, and HIIT burns ~500–700. Keep in mind that exercise calorie estimates are often overstated by fitness trackers by 15–30%.

Question 9

Is 1,200 calories a day enough?

Accepted Answer

A 1,200-calorie diet is the minimum recommended for women and is too low for most men. While it can produce rapid weight loss, it may lead to nutrient deficiencies, muscle loss, metabolic slowdown, fatigue, and hormonal disruption. Most adults get better long-term results with moderate deficits of 300–500 calories below TDEE. Consult a healthcare provider before starting any very low-calorie diet.

Question 10

Does your metabolism slow down with age?

Accepted Answer

Yes — metabolism naturally decreases by about 1–2% per decade after age 20, primarily due to loss of muscle mass (sarcopenia). By age 50, the average person burns 100–200 fewer calories per day than in their 20s. Regular resistance training, adequate protein intake (0.7–1g per pound), staying physically active throughout the day, and maintaining good sleep habits are the most effective strategies to counteract age-related metabolic decline.

Question 11

What is the thermic effect of food?

Accepted Answer

The thermic effect of food (TEF) is the energy your body uses to digest, absorb, and process nutrients. TEF accounts for about 10% of total calorie intake. Protein has the highest thermic effect (20–30% of calories consumed), followed by carbohydrates (5–10%) and fat (0–3%). This is one reason high-protein diets can aid weight loss — your body burns more calories just processing protein.

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