All living beings need energy to stay alive. In the case of humans, we get most of that energy by ingesting food and drinks. Our bodies then use that energy to keep our organs running, allowing us to do everything from breathing to walking. To measure the amount of energy in the food and drink we have consumed, or in the time we have spent performing a physical exercise, for instance, we use a unit called a calorie.
If we ingest more energy (calories) than we use up, our organism will store what is extra in the form of body fat. Which, over time might increase our chances of putting on weight. Hence, in order to keep balanced body weight, we should try to even out the amount of energy we consume with the amount we spent through physical activity and regular bodily functions.
The daily calorie guidelines for an adult male to keep a healthy body weight is roughly 2,500 kcal, whereas for an adult female the intake should be around 2,000 kcal. However, this is not a comprehensive formula. These values will vary depending on the person’s age, height and weight, level and constancy of physical activity, as well as his/her metabolism and lifestyle. Besides, if we end up having a higher calorie input today, that doesn’t mean we will gain weight automatically.