Tuesday, March 31, 2009

Best Way to Lose Weight - Diet or Exercise?

If you have been trying to lose some weight, and have done any research at all, you have no doubt read that dieting is best…or exercise is best. So which one really is the ‘best’ way to lose weight?

The short answer is that both ways may help you to lose weight, but neither one will work unless you understand some basic principles of how the body uses and stores calories.

We are all subject to what is called the Basal Metabolic Rate. This is the number of calories every living person needs to survive. It is based on the amount of calories needed to keep our organs functioning. Even walking to the fridge for some tempting snack or a cold one, and then back to the sofa for the next TV show would be considered ‘exercise’ when computing your BMR. It is the amount of calories you will burn if you stay in bed all day and do nothing.

The Basal Metabolic Rate is a clinical formula developed by countless measurements on countless people of both sexes and different ages. Your BMR decreases with both age and the loss of muscle mass. You will increase your BMR by adding muscle mass. Women and men have different formulas to compute their BMR.

A very precise BMR will factor in gender, age, weight, genetics, diet, body surface area, body fat percentage , body temperature, external temperature, glands, and the amount of exercise done on a regular basis. We can get a very accurate number without all this by using the following formula;

For women: BMR = 655 + (9.6 x weight in kilos) + (1.8 x height in cm) - (4.7 x age in years)

For men: BMR = 66 + (13.7 x weight in kilos) = 5 x height in cm) - (6.8 x age in years)

Note: 1 inch = 2.54 cm.

1 kilogram = 2.2 lbs.

As an example…a woman who is 30 years old…5′ 6″ tall (167.6 cm)…and weighs 120 lbs. (54.5 kilos)

BMR = 655 + 523 + 302 - 141 = 1339 calories a day

To find the numbers of calories we actually burn in a day we need to multiply our BMR by our activity. This is determined by the following types of physical activity;

Sedentary = BMR x 1.2 (little or no exercise, working at a desk all day)

Lightly active = BMR x 1.375 (light exercise 1 to 3 times a week)

Moderately active = BMR x 1.55 (moderate exercise 3 to 5 times a week)

Very active = BMR x 1.725 (hard exercise 6 to 7 times a week)

Extremely active = BMR x 1.9 (hard daily exercise + physical job)

Our 30 year old woman who is moderately active will need 2075 calories a day

This number is also referred to as ‘total daily energy expenditure’ or TDEE. This is the number that we have to know in order to plan a program to lose weight…no matter if we choose diet or exercise as the method.

Now back to our original question…which method is the best? Dieting all by itself will lower the BMR, making it more difficult to lose weight by simply reducing calories. Extreme dieting may actually have negative side-effects like hormone disruption (thyroid output).

Exercise without also reducing calories will result in very slow weight loss as we will not burn enough calories without very rigorous exercise…which usually results in an increase in food consumption. The recommended reduction for safe weight loss is between 500 and 1000 calories a day.

The bottom line concerning calories and weight loss is very simple. If we burn more calories then we consume we will lose weight. If we consume more calories then we burn we will gain weight. The trick is to find the balance using both diet and exercise.

Adding a moderately active to very active amount of exercise to your weight loss program also boosts your muscle mass which will increase your BMR. To keep the weight off it is necessary to lose it gradually…’crash’ or fad diets are not recommended.

Reducing your calories by just 500 a day off your TDEE will result in a loss of one lb. a week. This is an excellent rate to insure you will keep the weight off and you should not exceed 1000 calories a day, or 2 lb. a week. The combination of exercise and calorie reduction will give you the results you are looking for with the added benefit of becoming much more fit in the process.

A little effort will go a long way…happy weight loss.


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