The basic answer to this age-old questions is you simply must sustain a chronic caloric deficit. Period. While it’s become popular diet book lore to suggest you don’t need to eat less, the sad truth is in almost all cases you do.
How much you eat depends on a multitude of factors but depends on your activity levels, gender, age and goals.
The first step is to figure out your Basil Metabolic Rate – or simply the amount of energy (calories) your body requires to carry out daily functions. The Harris-Benedict Equation is the most widely recognized formula to determine this.
Determine your multiplier based on your level of activity and write it down. Then click on the BMR Calculator link near the bottom. Input your height, weight, age and gender. Multiply that number by activity formula you wrote down.
- If you are a 5’4” 180 lbs 40 year-old female, your BMR is 1550.
- If said female is moderately active, multiply this number by 1.375 which = 2131 calories.
- With me so far?
Now we have to decide on a deficit. Depending on your goals and your power/readiness/reality convergence potential, your deficit should be anywhere between 10 - 30%. Studies have shown that 30% deficits are difficult to attain while a 10% deficit may move the scale a little too slow for most. I recommend something closer to the 15-18% mark.
This puts the daily calorie target between 1740 and 1800 for the above female which is a reduction of about 320-350 calories per day.
OK - now you're equipped with the basics as to how to calculate your energy/caloric needs. The next installment will focus on macronutrient composition for optimal fat loss (a nerdy way of saying WHAT you should eat to get lean).
Image credit: Flickr/dinax