Want to lose weight? Eat less. Want to gain weight? Eat more. Want to maintain your weight? Continue eating the same amount you are now. I know this may sound like an over simplification on how to achieve your goals, but at the end of the day gaining or losing weight has a lot to do with the amount of calories you ingest in a day. There are only four components of food that supply calories: carbohydrates (4 calories per gram), proteins (4 calories per gram), fats (9 calories per gram), and alcohol (7 calories per gram). Vitamins, minerals, phytochemicals, fiber and water are all important and necessary to many bodily functions, but do not supply calories.
Exercise and daily activities can you help burn additional calories per day, but up to 70% of your calories are burned by your body to just sustain itself. This is often referred to as your metabolism but is also known as resting metabolic rate (RMR). Many factors contribute to how many calories you burn through RMR including, age, gender, muscle mass and even stress and the amount of sleep you get. Here is a formula to determine required calories based on your RMR:
Males: 66+ (6.22 x weight (lbs)) + (12.7 x height (inches)) – (6.8 x age)
Females: 655 + (4.36 x weight (lbs)) + (4.32 x height (inches)) – (4.7 x age)
Ex: A 30 year old male that is 6 feet (72 inches) tall and weights 175 pounds
66 + (6.22×175) + (12.7×72) – (6.8×30) = RMR is 1861 Calories per Day
Once you get an idea of how many calories you need in a day, you can then set the amount of calories that will be appropriate for your goals. In order to lose weight a deficit of 500-300 calories will be necessary to see progressive weight loss. For weight gain, an additional 300-500+ calories would be necessary to see growth.
Although these are general guidelines they may not work for every individual. It’s best to start here and make adjustments based on how your body responds (are you attaining your weight goals?). It’s extremely important that you continue to monitor your progress and adjust your caloric intake accordingly.