It sounds like you're referring to a "calories in vs. calories out" type of equation. First you need to understand that one pound of fat is made up of roughly 3,500 extra calories. So in order to lose one pound of fat, you need to create a caloric deficit of 3,500 calories.
Basically, you can create a deficit of calories in three different ways:
1. Eat fewer calories than you burn each day. Keep in mind that your body burns calories all day long as part of your basal metabolic rate (BMR), because it takes energy (calories) for your body to perform basic physiological functions that are necessary for life—breathing, digesting, circulating, thinking and more. On top of that, physical activity (bathing, walking, typing and exercising) uses even more calories each day.
It's not important for you to know what your BMR is. Your SparkDiet has already estimated your BMR based on variables like age, gender and weight, so you don't have to do any calculations. The calorie goal recommended in your SparkDiet plan will help you create a caloric deficit and lose weight.
Example: If you eat 500 fewer calories each day for a week, you'll lose about one pound of fat (500 calories x 7 days = 3,500 calories). Again, keep in mind that your SparkDiet has already done these calculations for you, so simply follow the calorie recommendations on your plan (don't eat less than is already recommended).
2. Burn more calories than you consume by increasing your physical activity. If you eat enough calories to support your BMR, but exercise more, you'll create a caloric deficit simply by burning extra calories. This works only when you're not overeating to begin with.
Example: Regardless of your BMR, if you exercised to burn an extra 500 calories each day, you'll lose about one pound of fat in a week (500 calories x 7 days = 3,500 calories).
3. A combination of eating fewer calories and exercising to burn more calories. This is the most effective way to lose weight and keep it off. It's much easier to create a substantial calorie deficit when you combine dieting with exercise because you don't have to deprive yourself from food, and you don't have to exercise in crazy amounts.
Example: If you cut just 200 calories a day from your diet and burned just 300 calories a day by exercising, you'd lose about one pound per week. Compare that to the other examples above—you're losing weight at about the same rate without making major changes to your diet or exercise routine. Some people hate to cut calories, while others hate to exercise, so a combination approach allows you to do more of whatever comes easier for you.
As long as you are consistent, your calorie deficit will "add up" over time, and you’ll slim down. But it's important to remember that your SparkDiet Nutrition and Fitness recommendations are already based on the goals you created. You don't have to do any extra math. Simply follow the Nutrition and Fitness recommendations on your Trackers and you'll be creating the deficit needed to reach your goal weight!
It's also important to note that although this math seems relatively simple, our bodies are very complicated and you might not always see the results you expect based on equations alone. Many other factors can affect your weight loss rate along the way.