Calorie Restriction and Weight Loss

How do calories affect weight?

A Answers (7)

  • AMarjorie Nolan Cohn, Nutrition & Dietetics, answered on behalf of Academy of Nutrition and Dietetics

    Simply stated, if you take in more calories than you need on a daily basis, the excess calories turn into extra weight. Think of food as fuel and your body as a car. Food is the energy your body "runs" on. Overeating is like over-fueling; any excess fuel you don't "run on" turns into fat. This is how weight gain occurs. Because of this basic principle (calories consumed versus calories spent), the cause of weight loss is just as straightforward as the explanation of weight gain. If you consume fewer calories than you burn, you will lose weight. The basis of every weight loss diet is based on this. Whether you follow a low-fat or low-carbohydrate/high protein diet or you reduce portion sizes, all varied means to the same end: fewer calories consumed.

  • A calorie is a measure of the energy value of food. According to experts, maintaining a healthy weight is often a calorie-balancing act -- making sure that the number of calories you eat balances with the energy you use in your daily activity.
    • If you eat more calories for a period of time, you'll gain weight -- unless you increase your activity level to offset the imbalance.
    • If you eat less or increase your activity, you can expect to lose weight. If you do both, you can expect to lose even more.
    • If you're using all the calories you're eating, you've achieved a balance that will allow you to keep weight off for the long term.
  • When you carry excessive weight it causes the body the use more energy to perform functional motion and work. Muscles must work harder to move more weight. Lungs must work harder to get oxygen needed to feed extra body tissue. In addition, all tissue needs blood flow to live and be nourished. Thus, the cardiovascular system must work harder to push blood to more body tissue. When these systems work harder it must consume energy (or calories) to perform the work.  This is why the somebody who is heavier will burn more calories than someone who is lighter.

  • Your body requires a certain number of calories per day to maintain your current weight. This is known as your caloric maintenance level. It's the number of calories required by your body to do everything it needs to do (exercise, brushing your teeth, pumping blood, keeping organs functioning properly, etc.). Calories are what our bodies use for energy, so to do what needs to be done, a certain number of calories are needed.

    We supply our bodies with these calories through eating and drinking. If we consume exactly the same number of calories that our bodies need each day, our weight would remain exactly the same. For example, if your calorie maintenance level was 2500 calories, and you consumed 2500 calories per day, your weight would not change. All the calories you take in would be used or burned. This is how you maintain your weight, by giving your body only the calories that it needs. No more, no less.

    If you consume more calories than this maintenance level, your body will store the excess calories as fat. So, for example, if your maintenance level was 2500 calories, and you consumed 3000 calories per day, you would gain weight. You are giving your body more calories than it would burn. This is the cause of weight gain.

    On the other hand, if you do the opposite and give your body less calories than it needs, your body will convert your stored body fat into energy and use that instead. This is cause of weight loss. Sticking with the same example as before, if your daily maintenance level is 2500 calories, and you consume 2000 calories per day, you will lose weight.

    In short, consume the same number of calories that your body needs each day and you maintain your weight. Consume more calories than your body needs and you gain weight. Consume less calories than your body needs and you lose weight.
  • Controlling your weight isn't a magic trick, rather it's simple math. Maintaining your weight in a healthy range requires a balance between the calories you take in through food and drink and the calories you burn through physical activity.

    A good mind-set for approaching calorie control is to think of the calories you consume and the calories you burn as your calorie budget. How do you want to "spend" those calories?
    • To lose weight: Consume fewer calories than you burn each day. Either cut back on the calories you consume, exercise more or do both.
    • To gain weight: Tip the balance the other way. Take in more calories than your body uses. However, your body still needs physical activity to remain healthy, so keep moving.
    Why focus on calorie balance? Your body stores most of the excess calories you consume as fat. Just 100 extra calories a day adds up to 10 pounds in a year.
  • Calories can affect your weight by increasing it or decreasing it. All considering aside it can even keep it the same weight. One pound is equal to 3500 calories. So when we are looking at losing weight we must be sure to burn more calories than we eat. When we are looking to add weight, we must eat more than we burn. (It is recommended that they are healthy calories) Do not just eat whatever and say you are eating more than you burn. And if you have reached your goal weight and want to maintain that be sure to eat as many calories as you burn. One way to help determine how many you burn daily is an Exerspy...great calorie management program. One thing you need to realize when it comes to calories and weight is that the process does not happen overnight. It takes determinination and belief in yourself. It takes time and commitment, but with the right goals and motivation anything is possible.
  • ADavid W. Brinton, MD, Sports Medicine, answered on behalf of Intermountain Healthcare
    Most experts still agree that successful weight loss and weight maintenance depends on balancing energy input with energy output.
    A calorie is a measure of the energy value of food. Here’s how it works:
    If you eat more calories than you use up with activity, you’ll gain
         weight. If you eat fewer calories than you use up with activity, you’ll lose
         weight. If you eat the same amount of calories you use up with activity,
         you’ll maintain your weight.
    Helpful? 1 person found this helpful.
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How can I eat a healthy meal under 500 calories?