Outline a simple method to estimate daily energy needs for weight management.

• A. Use BMI alone to estimate energy needs.
• B. Assume fixed 2000 kcal/day for all adults.
• C. Estimate BMR with a formula (e.g., Mifflin-St Jeor), multiply by activity factor to get total energy expenditure, then create a modest deficit (e.g., 500 kcal/day) for gradual weight loss.
• D. Base on age only.

Answer: (C)

Estimating daily energy needs for weight management starts by quantifying how much energy the body uses in a day. The most effective method uses a resting energy estimate, like the Mifflin–St Jeor equation, which takes into account sex, age, height, and weight to approximate BMR—the calories the body needs at rest to keep essential functions going. Then this number is adjusted for activity by applying an activity factor that reflects daily movement and exercise, giving the total daily energy expenditure. With that personalized target, creating a modest deficit supports gradual, sustainable weight loss; about 500 kcal less per day is a common starting point, often yielding roughly a half-kilogram weekly loss while preserving nutrients and energy for daily activities. This approach respects individual differences in body size and activity, rather than assuming everyone needs the same calories.

Using BMI alone doesn’t tell you how much energy someone uses day to day, since it doesn’t reflect body composition or activity. Relying on a fixed number like 2000 kcal ignores personal differences in size and metabolism, and basing needs on age alone misses crucial factors like activity level and body mass.