The consumption of calories and the maintenance of weight seem like simple arithmetic, but it can vary from person to person. It also requires an awareness of the content of foods that you are eating. However, a good, healthy diet should not be complicated. Maintaining weight is simple if you are eating the right things.
The number of calories you need depends upon several factors besides gender. They include age, weight, activity level and genetics. Individuals are different, but on average, men have more weight, and also more lean weight, than women, so this generally necessitates the consumption of more calories throughout the day. Extra weight requires more energy to do the same amount of work. Muscle mass weighs more than other tissue, and it is an active tissue, burning calories on its own.
According to work by exercise physiologists William McArdle and Frank Katch, the average total number of calories used for an adult male in the United States is 2,700 to 2,900 calories a day. This includes the basal metabolic rate, or the rate at which the body must work just to fulfill its most basic functions, plus the amount of activity that you do during the day. It is also an average and should not be applied to every single male. Weight lifters, athletes and just about any physically active person will burn more calories in a day.
Genetics is a large factor in your basal metabolic rate, but even without the ability to account for genetics, there are still generally accurate formulas available, including the Harris-Benedict formula. For men, this formula is 66 + (6.23 x weight in pounds) + (12.7 x height in inches) - (6.8 x age in year). You will have to estimate how much activity you are doing to find the total number of calories that you are burning. Sedentary individuals should multiply the basal metabolic rate by 1.2. Lightly active individuals—light exercise or sports one to three days a week—should multiply by 1.375. Moderately active individuals—moderate exercise or sports three to five days a week—should multiply by 1.55. Very active individuals—hard exercise or sports six to seven days a week—should multiply by 1.725. And extremely active individuals—hard daily exercise or sports, physical job or professional athleticism—should multiply by 1.9.
A calorie is essentially a unit of energy. According to Medline Plus, it measures the amount of food needed to raise a gram of water a single degree Celsius. Consuming the same number of calories you burn, therefore, will fulfill your exact energy requirements throughout the day. Fats, carbohydrates and proteins are the only kinds of nutrients that your body can use for energy. Fat is the most energy- dense of the three. It contains 9 calories per gram, compared to 4 calories for proteins and carbohydrates.
Besides the number of calories, the quality of the calories also matters. Extra energy is stored as body fat when there is too much energy, but eating foods such as fiber and protein will promote a feeling of fullness and slow the absorption of molecules into the bloodstream. Simple, refined carbohydrates and highly calorie dense foods have a greater proclivity to be converted into body fat.