What Factors Influence My BMR?

Many factors affect your BMR:

• Genetics: Some of us are born with a faster metabolism and some with a slower metabolism.
• Gender: Men have a greater muscle mass and a lower body fat percentage so they generally have a higher BMR.
• Age: Younger people have more actively dividing body cells. Cell division consumes a lot of energy and that is why their metabolism is very fast. Your BMR declines approximately by 2% every 10 years after you turn 20.
• Height: The taller a person is, the higher their BMR because their body surface area is larger and so heat loss is greater.
• Body composition: It requires more energy to sustain muscle mass than fat. The more muscle mass you have, the higher your BMR.
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• Glands: Thyroxin (produced by the thyroid gland) is a key BMR-regulator, which regulates the metabolic activity of the body. The more thyroxin produced, the higher your BMR. Adrenaline also increases your BMR but to a lesser extent.
• Hormones: Some surveys have found that a woman's metabolism dips just before ovulation and again at menstruation. BMR then starts to rise when the body temperature climbs. Menopause causes the metabolism to slow down.
• Stress: Stress hormones can raise your BMR.
• Exercise: This not only burns calories, it also helps raise your BMR by building extra muscle.
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• Diet: Excessive calorie restriction, or starvation, can dramatically reduce your BMR.
• Stimulants: Your metabolic rate rises temporarily after ingesting caffeine and nicotine. This also raises your heart rate.
• Temperature: A low external temperature causes an increase in BMR. This creates the extra heat needed to maintain the body's internal temperature.