The Math of Weight Loss

Posted on July 17th, 2007 in Nutrition

calculatorWith so many fad diets out there, it can be tough to figure out which ones really work and which ones are a waste of time. It becomes easier to see through the gimmicks once you understand a universal fact about weight and diet. When it comes to losing weight, it doesn’t matter WHAT you eat. There is only one trick to losing weight: burn more calories than you consume.

Food is an energy source, and calories are a measure of that energy. We consume calories through food, and our body uses this energy in several ways:

  • Involuntary body functions - The human body is a complex system and it needs energy to operate all of the organ systems in the body. These functions include digesting food, filtering urine, processing thoughts, blinking our eyes, breathing, and keeping our heart beating. There are thousands of vital processes going on inside the body at all times that we don’t even think about, and they’re all powered by the energy from food. The amount of calories burned by our involuntary body processes while at rest is referred to as our basal metabolic rate (BMR).
  • Voluntary body movements - It takes energy to move any of our muscles. We spend all day using our muscles to get us from place to place. Every time you walk across the living room, raise your arm, or do any movement at all, it’s powered by the food you’ve eaten.
  • Exercise – Exercising is an extension of voluntary movements. It’s more intense than ordinary movement and is typically done in short intervals. Because of the intensity, it burns many more calories than ordinary routine movements. If you exercise or live an active lifestyle, you’ll need more calories to power those movements.

After using calories to power the three items listed above, our body will store any remaining calories away to use at another time. This is what fat is – the body’s energy stores lying in wait for when they’ll be needed. Our bodies are evolved from a time when food wasn’t so readily available. Like other animals, humans ate when they could and whatever energy the body didn’t need was stored away for times of famine. Our current society is no longer faced with these problems, so instead of starvation we have to worry about the woes of excess weight storage.

To lose weight, we need to create an energy deficit. We need to burn more energy (or calories) than our body has ready, so it will be forced to tap into those fat stores and use them up. That’s the secret of how to lose weight – simply burn more calories than you eat so your body will be forced to use fat to fuel its energy needs. It’s not a gimmick, but a mathematical certainty.

Of course, if it were that simple the weight-loss industry wouldn’t be so prosperous. It’s not easy to figure out how many calories you need, and how to burn more than you take in. Furthermore, it varies widely from person to person. Many different factors go into determining exactly how many calories a person burns at rest, and during exercise. Genetics gives some a much easier time controlling their weight with little effort, while others must constantly be on guard.

But these low carb diets really work! I’m sure you know people who have lost weight on one fad diet or another. Although these gimmicks try to convince you that they’ve figured out the easiest way to lose weight, it boils down to them selling a new and exciting way of packaging the same old message – eat less calories!

For example, take a low-carb diet. If you eat little or no carbs, you can’t eat bread, pasta, or rice. These foods can pack quite a caloric punch – they are very dense in calories, and it’s easy for most people to eat more than a standard serving size. By eliminating carbs, people are effectively limiting the number of total calories they are taking in, and they’ve created the calorie deficit necessary for weight loss.

Diets like this will work if they create a calorie deficit, but it can be extremely difficult (not to mention unhealthy!) for people to stick to a strict and regimented eating plan long-term (Read more about Why Diets Don’t Work).The same effect can be created by learning how to monitor your calories with a balanced diet including all the foods you love. It’s not easy to figure out exactly how much to eat for maximum health. But the more information you have, the easier it becomes to learn what works best for your unique body.

So how many calories do we need? We’ll discuss this topic in the upcoming article, Estimating Daily Calorie Needs.

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  1. on June 19th, 2008 at 1:44 am

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