Читать книгу The Renaissance Diet 2.0 - Mike Israetel, James Hoffmann - Страница 35

Calorie needs can vary a great deal from one person to the next. A number of factors contribute to individual variation in daily calorie needs. The following is a list of some of these factors:

Body Size: Larger people have more cells and bigger cells, so it takes more energy to power their bodies.

NEAT: Non-Exercise Activity Thermogenesis, or NEAT, is the amount of calories you expend on daily tasks, including working, studying, walking to the store, moving your hands while you talk, and even fidgeting. Calorie expenditure by NEAT activities can vary from tiny to enormous and, in most cases, account for more daily calorie burning than formal exercise.

Exercise/Training: Any form of working out that you do requires energy, and the more you work out, the more energy you need.

Height and Body Proportions: Taller people usually have more surface area than shorter people of the same weight. It takes quite a few calories to keep body temperature stable with more surface area exposed to the environment. Likewise, any other physical features that increase surface area can increase metabolism.

Stress: Contrary to popular belief, stress actually boosts calorie burning via constant low-level activation of fight-or-flight pathways. It is not at all uncommon for people to gain weight when chronically stressed, but this is generally due to stress-induced excess eating or water retention from stress hormones. Stress on its own usually contributes to weight loss.

Recovery Demands: Not only does hard training burn calories directly, it causes damage to muscle tissues (deliberately) and depletes energy stores. What this means in the grand scheme of things is that your body will require extra calories to perform repairs.

Genetic Metabolic Factors: Some people have very efficient metabolisms and convert more of the energy from the food they eat into other usable forms of energy. Though metabolisms do not vary widely on average, over a long period of time these small variances contribute to the ease or difficulty of weight loss observed across dieters.

Percent Body Fat: Fat is a heat insulator and requires a bit less energy to be maintained than muscle. Thus, individuals who are leaner will have to burn more calories by a small fraction to stay the same weight than similarly sized people with more body fat and less muscle. On the other hand, carrying extra fat can cause movements to become less economical, thus increasing energy expenditure. A surplus of fat can also make thermoregulation in the heat more difficult, requiring additional energy expenditure.

Drug Intake: Stimulants like caffeine boost the metabolic rate to a small extent and burn a tiny amount of extra calories.

Sex: Due mostly to body size, muscle mass, and hormonal differences, men burn more calories than women. If body size and muscle mass differences are obviated, the remaining difference is very small, but still exists.