I have developed a conditon called hypothyroidiam that definately slows down the metabolism and eating a mere 1000 calories per day will put heaps of weight on me. If I eat 800 calories I can lose a little weight but it is a real battle (even with the synthetic thyroid medication the doctors have given me) eating only 800 cals per day makes me lose hair, have muscle and joint aches, calcium doesn't seem to reach my teeth and I faint from a lack of iron even though I consume lots of spinach and daily iron tablets.
There is such a thing as slow metabolism. But it is uncommon. Most overweight individuals are not overweight because of a slower than average metabolism but because they eat too many calories and don't get enough exercise.
Metabolism is the complex biochemical process by which the food you eat is converted into the energy your body needs to function. Basal metabolic rate (BMR) is the amount of calories you burn at rest.
Your body composition is one of the primary factors that determine BMR. The more lean muscle you have, the more calories you burn. This is why men â€” who typically have more lean muscle than women do â€” tend to lose weight faster and gain it more slowly. It's also why experts recommend strength training to build muscle mass.
BMR is also affected by how much you exercise. All physical activity, not just strenuous activity, increases the number of calories you burn.
Only a small number of people burn fewer calories at rest than they should, according to estimates based on their height, weight and age. Because people who weigh more have more muscle as well as fat, overweight people usually have an increased metabolic rate, contrary to popular belief.
Your metabolism slows somewhat with age
. So you may need to decrease your calorie intake or increase your physical activity accordingly. Also, some medical conditions â€” such as hypothyroidism and Cushing's syndrome
â€” can decrease BMR or alter your muscle-to-fat ratio. A doctor can test for these conditions.
A funny but accurate 3 page letter was sent to Dr Phil McGraw when he foolishly once said on the Oprah show that Hypothyroids can lose weight they just have to work a LITTLE harder. click here - http://thyroid.about.com/cs/personalpag ... l.htm?nl=1