Let's set the scenario. You watch one of your best friends (spouse, boyfriend, etc) eat whole pizzas all the time, but, they never gain any weight! You, on the other hand, eat one piece of pizza and the next day, your pants don't fit! A little exaggerated, but I am sure most of you understand the feeling of seeing some people eat anything they want and never gain an ounce.
We are going to break down what metabolism is and what you can do to influence it. While genetics plays a role in your metabolic rate, there are still many things that you can do to help!
What is Metabolism?
Metabolism is the rate at which your body burns calories.
Factors Affecting Metabolism
1. Body size: Tall, thin people have higher metabolic rates than short, wide people.
4. Gender: Men have higher metabolic rates than women do. Sorry women.
7. Food/beverage intake
9. Cold exposure: Studies have shown that frequent cold exposure (cold showers, cold drinking water, less bundling in the winter) increases metabolism.
Your metabolism slows down as you age. What can you do about that? One thing you can do to avoid weight gain is to decrease the amount of calories you consume.
Women, your metabolism fluctuates throughout your menstrual cycle. This is the reason why at certain weeks you are eating everything in sight. Pregnant women, during the second half of pregnancy, metabolic rate increases due to fetal growth and the mother's increased cardiac workload.
Athletes with greater muscle mass have a 5% higher metabolic rate than non-athletes. This is largely due to their increased fat free mass. By participating in strength training exercises (chest press, overhead press, lat pulldown, etc), you are increasing your resting metabolism. This means that you are increasing the amount of calories you burn after exercising. This effect can last for up to 24 hours. High intensity interval training has also been shown to increase metabolism for 2-3 hours after exercise. Lastly, having more muscle in general will boost your metabolism because of the calories needed to maintain them.
Spicy foods and caffeine both stimulate your metabolism. Meals with chili may increase metabolic rate as much as 33% for a span of 3 hours. By ingesting caffeine every 2 hours for 12 hours, your metabolism is boosted by about 10%. Green tea has also been well known for the benefits of EGCG, which boosts metabolism. What's the catch? You can only reap the benefits of green tea by regular consumption of 5-6 cups of green tea per day.
It is important to try and get in about 7-8 hours of sleep per night. While resting, your body burns calories performing basic processes (repairing damaged tissues, breathing, pumping blood). Your resting metabolism accounts for about 65% of your daily calorie burning. With chronic lack of sleep, your metabolic function becomes altered and slowed.
To sum it all up, the major factors in increasing metabolic rate are exercise and sleep. While coffee, spicy foods, and green tea can help boost metabolism, the amount you have to consume on a daily basis is quite high. The best ways to boost metabolism are to be mindful in caloric changes (decreasing calories as you age), using strength exercises, and getting enough sleep every night.
Mahan L, Escott-Stump, S. "Food, Nutrition, and Diet Therapy." Saunders. 2004. http://www.ncbi.nlm.nih.gov/pubmed/17906191