男女热量需求，真的不一样吗？
Is it true that men need to consume more calories than women? “Generally speaking, yes,” says Bethan Crouse, a sports nutrition expert from Loughborough University, “but it is not a rule that fits everyone.” Humans burn calories to power everything from movement to sleep. For adults aged between 19 and 64, daily energy needs are about 2,000 calories for women and 2,500 for men. Needs are very different for children and teenagers, and they usually fall with age. However, averages hide a lot of differences between individuals.
One main reason men usually need more calories is that they often have a higher resting metabolic (新陈代谢的) rate. This means they burn more energy even when at rest. The difference is mostly because of body composition. On average, men have more lean muscle, while women tend to have a higher percentage of body fat. Muscle burns more calories than fat, even when the body is not active.
These differences in muscle are not mainly because of diet or exercise, but because of hormones (荷尔蒙). Certain natural substances in the body, which are typically more present in men, support the development of muscle. So, even if a man and a woman have the same height, age, weight, and workout plan, their calorie needs may still be different. However, Crouse points out there is also individual variation.
For example, think of a muscular woman and an average man. “That woman may need more calories than the man when resting, and she probably exercises more too, which increases her needs further.” Long-term dieting can also change things. Eating too few calories for a long time can lower the body’s base energy needs, like turning down a “metabolic dial”.