Your particular basal metabolism is determined by a number of factors, including your body size and composition. People who are heavier or have greater muscle burn more calories even when they are at rest. Lighter individuals with less muscle may actually burn fewer calories per day. However, all else being equal, the more energy you take in compared to the amount you burn off, the greater the calorie deficit you will experience. In addition, there are other factors that can affect how many calories you burn in a day. For example, if you spend a lot of time sitting down, you need to make sure you're not consuming too much sugar or processed food. This is especially important if you are trying to lose weight. Eating these types of foods will add extra calories to your daily intake and cause you to gain weight instead of losing it. Finally, exercise affects how many calories you burn. The more activity you do, the more calories you will burn. Exercise also increases your metabolic rate after you finish so there's no need to worry about burning more than you eat. As long as you aren't overexerting yourself, then having a job that requires physical activity is a great way to increase your daily energy expenditure without changing your lifestyle too drastically.