Metabolism 101
Human metabolism is made up of all energy creating and energy consuming reactions in the body. When most of us discuss metabolism, however, we are referring to calories (as a measurement of energy) burned each day. Some people are convinced that they have a ‘fast’ metabolism (these are the folks you envy who can devour huge portions of pasta and dessert without ever gaining an ounce), while others are convinced that they have a ‘slow’ metabolism (these are generally the people who insist that they gain weight just looking at a piece of cheesecake). Is there really a dramatic difference between the two? Probably not. But there is a difference, and you may be able to improve your metabolism by making a few simple changes.
Total metabolic rate (TMR), which represents your total daily caloric needs, is made up of three major components: resting metabolic rate, thermic effect of activity, and thermic effect of feeding. Resting metabolic rate (RMR) accounts for the greatest share of TMR, approximately 60-75%, and includes the energy used to keep all your major organs running. Genetics plays a small role in RMR (about 10%), but most of the variability in RMR is dependent on three factors: age, sex, and fat-free mass (muscle, bone, water). While you can’t control your age or sex, you can control your fat free mass. Beginning at age 30 or so, RMR drops by about 3% per decade, mainly due to a drop in muscle mass. But this drop in muscle is partially preventable with strength training, which is why it is one of the most important things that you can to do increase, or at least limit the decrease, in metabolism.
The second component of TMR is the thermic effect of activity, which accounts for approximately 15-30% of your total daily caloric expenditure. The thermic effect of activity includes both exercise related activity like going for a run or lifting weights and non-exercise activity like working, leisure activities and even fidgeting. When it comes to exercise, how long you workout is not the only factor to consider. Studies show that more intense exercise can produce a greater temporary increase in metabolism which lasts longer. So to maximize metabolism, try exercising both longer and harder on a regular basis.
Non-exercise activity thermogenesis, also know as NEAT, may play an even greater role in the thermic effect of activity. Research by Dr. James Levine at the Mayo clinic shows that NEAT can burn 350 to 1000 extra calories per day. But in the average person, NEAT has dropped 100-200 calories per day due to the mechanization of our society which require us to be much less physical on a daily basis. So it is critical to add back in activity, both at work and at home, whenever possible to maximize metabolism.
The final component of TMR is the thermic effect of feeding (TEF) which represents the calories burned during the digestion and absorption of food. TEF accounts for only about 10% of TMR but it is another area in which you have some control. Studies show that protein has a slightly higher thermic effect than fat or carbohydrates so basing your diet around lean protein may help boost metabolism slightly. In addition, irregular eating patterns can decrease the thermic effect of feeding so if you want to maximize metabolism, try eating every 4 hours or so.
I know it may seem like your genes are working against you in the metabolism department, but as you can see, you actually have a lot more control than you realize.
Tuesday, August 12, 2008
Tuesday, August 5, 2008
skinny on supplements
Here are my recommendations for the three basic supplements that are the foundation of a healthy lifestyle:
Basic Multivitamin – Taking a daily multivitamin does not replace a healthy diet, but studies show that it may play a role in chronic disease prevention. What if you eat a balanced diet? Our soil quality has deteriorated significantly in the past 50 years, so you may not get every nutrient that you need from your diet alone. Plus, most Americans don’t even come close to eating the recommended 5-9 servings of fruits and vegetables per day. So think of a daily multivitamin as an insurance policy for good health. The FDA does not regulate the supplement industry, so stick with a nationally recognized brand and don’t pay extra for “special” formulations as most are just marketing gimmicks. If you’re interested in seeing how different vitamins measure up, visit www.consumerlab.com, an independent supplement testing website.
Vitamin D – In recent years, our understanding of the importance of Vitamin D in disease prevention has increased considerably. Vitamin D is essential for calcium absorption, so it is important for strong, healthy bones, and recent research suggests that Vitamin D may reduce the incidence of cancers including breast, colon and lung. Deficiencies may also play a role in diseases such as multiple sclerosis and certain types of arthritis. Current recommendations range by age as the formation of Vitamin D in the skin during sun exposure decreases with age. The Institute of Medicine, part of the National Academy of Science, recommends a daily intake of 200 IU until the age of 50, 400 IU from 51-70 and 600 IU for ages 71 and older. There are not many foods that naturally contain Vitamin D and since sun exposure is often limited due to the risk of skin cancer, a supplement is probably the best way to go to ensure that you get enough each day. The recommended daily intake of calcium for adult men and women (ages 19-50) is 1000mg and 1200mg per day after the age of 50. Calcium is more easily obtained from food, so try to get at least half of your daily calcium from your diet, but you are probably best off taking a calcium + vitamin D supplement to ensure that you reach your target daily dose for each important nutrient.
Omega 3 Fatty Acids (EPA/DHA) – Unless you eat a variety of fish on a frequent basis, I suggest taking an omega 3 fatty acid capsule. Studies suggest that EPA and DHA may decrease your risk of heart disease, dementia, joint pain, and age-related macular degeneration, the leading cause of blindness in older Americans. For people who already have heart disease, the American Heart Association recommends taking 1000mg of fish oil per day. Flaxseed oil capsules, which contain the omega 3 fatty acid ALA, have not been found to have the same health benefits and should not be substituted for fish oil capsules.
Basic Multivitamin – Taking a daily multivitamin does not replace a healthy diet, but studies show that it may play a role in chronic disease prevention. What if you eat a balanced diet? Our soil quality has deteriorated significantly in the past 50 years, so you may not get every nutrient that you need from your diet alone. Plus, most Americans don’t even come close to eating the recommended 5-9 servings of fruits and vegetables per day. So think of a daily multivitamin as an insurance policy for good health. The FDA does not regulate the supplement industry, so stick with a nationally recognized brand and don’t pay extra for “special” formulations as most are just marketing gimmicks. If you’re interested in seeing how different vitamins measure up, visit www.consumerlab.com, an independent supplement testing website.
Vitamin D – In recent years, our understanding of the importance of Vitamin D in disease prevention has increased considerably. Vitamin D is essential for calcium absorption, so it is important for strong, healthy bones, and recent research suggests that Vitamin D may reduce the incidence of cancers including breast, colon and lung. Deficiencies may also play a role in diseases such as multiple sclerosis and certain types of arthritis. Current recommendations range by age as the formation of Vitamin D in the skin during sun exposure decreases with age. The Institute of Medicine, part of the National Academy of Science, recommends a daily intake of 200 IU until the age of 50, 400 IU from 51-70 and 600 IU for ages 71 and older. There are not many foods that naturally contain Vitamin D and since sun exposure is often limited due to the risk of skin cancer, a supplement is probably the best way to go to ensure that you get enough each day. The recommended daily intake of calcium for adult men and women (ages 19-50) is 1000mg and 1200mg per day after the age of 50. Calcium is more easily obtained from food, so try to get at least half of your daily calcium from your diet, but you are probably best off taking a calcium + vitamin D supplement to ensure that you reach your target daily dose for each important nutrient.
Omega 3 Fatty Acids (EPA/DHA) – Unless you eat a variety of fish on a frequent basis, I suggest taking an omega 3 fatty acid capsule. Studies suggest that EPA and DHA may decrease your risk of heart disease, dementia, joint pain, and age-related macular degeneration, the leading cause of blindness in older Americans. For people who already have heart disease, the American Heart Association recommends taking 1000mg of fish oil per day. Flaxseed oil capsules, which contain the omega 3 fatty acid ALA, have not been found to have the same health benefits and should not be substituted for fish oil capsules.
While this list is not comprehensive, and specific needs may vary, the three supplements discussed above are a good starting point for almost every one at any age for optimal health – and think of how much more room you’ll have in your medicine cabinet now!
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