决定你的基础代谢率（休息时的新陈代谢）。 运用哈里斯本笃方程计算您每日所需卡路里，一旦你计算你的基础代谢率（BMR），你可以在活动的不同阶段评估你的总的卡路里需要。

I'm interested in that, but I only have a few mins. Can you give me at most the first 500 characters of a detailed explanation in English about that?
You can find an online calculator, or you can use the following formulas, depending on your gender:  Women: BMR = 655 + (4.35 x weight in pounds) + (4.7 x height in inches) - (4.7 x age in years)  Men: BMR = 66 + (6.23 x weight in pounds) + (12.7 x height in inches) - (6.8 x age in year) Once you have calculated your BMR, you can estimate your total calorie needs for different levels of activity.  Decreasing your metabolism means you are "turning down" your body's internal furnaces, which lowers