We care because this has some very important implications for human obesity. With such a powerful system in place to keep body fat mass in a narrow range, a major departure from that range implies that the system isn’t functioning correctly. In other words, obesity has to result from a defect in the system that regulates body fat, because a properly functioning system would not have allowed that degree of fat gain in the first place.
So yes, we are gaining weight because we eat too many calories relative to energy expended. But why are we eating too many calories? Because the system that should be defending a low fat mass is now defending a high fat mass. Therefore, the solution is not simply to restrict calories, or burn more calories through exercise, but to try to “reset” the system that decides what fat mass to defend. Restricting calories isn’t necessarily a good solution because the body will attempt to defend its setpoint, whether high or low, by increasing hunger and decreasing its metabolic rate. That’s why low-calorie diets, and most diets in general, typically fail in the long term. It’s miserable to fight hunger every day.
Metabolism is the process by which your body converts what you eat and drink into energy. During this complex biochemical process, calories in food and beverages are combined with oxygen to release the energy your body needs to function.
Even when you're at rest, your body needs energy for all its "hidden" functions, such as breathing, circulating blood, adjusting hormone levels, and growing and repairing cells.
The number of calories your body uses to carry out these basic functions is known as your basal metabolic rate — what you might call metabolism. Several factors determine your individual basal metabolic rate.
So yes, we are gaining weight because we eat too many calories relative to energy expended. But why are we eating too many calories? Because the system that should be defending a low fat mass is now defending a high fat mass. Therefore, the solution is not simply to restrict calories, or burn more calories through exercise, but to try to “reset” the system that decides what fat mass to defend. Restricting calories isn’t necessarily a good solution because the body will attempt to defend its setpoint, whether high or low, by increasing hunger and decreasing its metabolic rate. That’s why low-calorie diets, and most diets in general, typically fail in the long term. It’s miserable to fight hunger every day.
Metabolism is the process by which your body converts what you eat and drink into energy. During this complex biochemical process, calories in food and beverages are combined with oxygen to release the energy your body needs to function.
Even when you're at rest, your body needs energy for all its "hidden" functions, such as breathing, circulating blood, adjusting hormone levels, and growing and repairing cells.
The number of calories your body uses to carry out these basic functions is known as your basal metabolic rate — what you might call metabolism. Several factors determine your individual basal metabolic rate.
