Fat Burning 101
The Ultimate Crash Course
By PR Cole
MS, RD Candidate, Columbia University
PRCole@fuelthefighter.com
http://twitter.com/fuelthefighter
Trimming away those extra pounds can be a real challenge- especially if you're already on the leaner side and you're aiming for a more defined physique. Weight loss can be especially tricky for athletes who are trying to find a balance between cutting calories and eating to support intense workouts.
What's involved in losing a pound of fat?
To lose one pound of fat you need to burn 3,500 calories. So over the course of a week, you'd need to burn 500 calories each day. This is best achieved by decreasing food intake, and increasing physical activity. If you burn 300 calories daily through exercise then you need to cut out about 200 calories from food in addition to that.
What type of exercise is best for losing weight?
This can be a little confusing. While it's true that low intensity exercise (like power walking or light cardio) is best for burning fat as a fuel for exercise, high intensity cardio will burn more overall calories in the same time period. Since weight loss is all about the calorie deficit, I recommend opting for more intense workouts when possible. Think about it like this, a 150 lb man will burn about 100 calories from either walking or running 1 mile. If he runs the mile he'll be able to burn those calories in half the time.
How much should I restrict if I'm trying to lose weight?
Since you want to lose fat and not muscle, you need to make sure you keep your protein intake high. You also need to keep up the carbs since they fuel your workouts. Since fats are very important to general health (like essential omega fats) don't cut them out completely. The following are the minimum nutrients needed to help support an active individual trying to tone up.
Minimum calories needed: About 14 calories per pound of body weight
Minimum protein requirement: About 0.6 grams per pound of body weight
Minimum carbohydrate requirement: About 2.3 grams per pound of body weight
Minimum fat requirement: About .7 grams of fat per pound of body weight
What's in all those "fat burning" supplements?
The market is saturated with a variety of over the counter supplements that claim to promote weight loss. The following is a summary of some of the main "fat burning" ingredients.
Ingredient | Origin | Theory behind it | Dose | Main Side Effects |
Chitosan | The exoskeleton of crustaceans | Remedy to reduce fat absorption | 2-3 g daily | Gastrointestinal discomfort (constipation and flatulence) |
Ephedra (aka ma huang) | Derived from an evergreen shrub in central Asia | Often combined with caffeine (guarana/kola nuts) to promote fat loss. Also acts as a stimulant to increase energy | No more than 10 mg per day * | Head ache, increased heart rate, increased blood pressure, insomnia, gastrointestinal distress |
Green tea extract | Produced from green tea leaves | Reported to increase energy expenditure and inhibit the breakdown of dietary fat. | 25% polyphenols per day | Potential for liver damage, speak with your doctor if you have a liver condition before taking this supplement. Overconsumption may interfere with iron absorption |
Hydroxy-methyl butyrate | Formed from the breakdown of the amino acid Leucine | Helps support increases in lean body mass | 3 g daily | Few adverse effects |
Yerba Mate | Derived from an evergreen tree in South America | Often prepared with guarana, this supplement delays the time it takes food to empty the stomach, which decreases hunger | 670 mg daily | Few adverse effects |
Yohimbe | Made from an evergreen tree native to Central America | Functions as a stimulant of the nervous systems | 20 mg daily | Few adverse effects, however higher doses may cause rapid heart rate, high blood pressure, insomnia, panic attacks, hallucinations, headaches, and dizziness |
* Note that there has been much controversy in recent years regarding the safety of supplements that contain ephedra since the compound has been implicated (though not conclusively) in a handful of deaths. Currently, the federal government has issued a ban for doses of ephedra that exceed 10 mg. California, Illinois and New York have banned the substance entirely.
Use discretion if you decide to supplement since few scientific studies have examined how these substances interact with the body in the long run. It's a good idea to consult a physician before starting any regimen of supplements to make sure that they won't interact with any current prescriptions or medical conditions.
References
Pittler, M. H., & Ernst, E. (2004). Dietary supplements for body-weight reduction: a systematic review. [Review]. American Journal of Clinical Nutrition, 79(4), 529-536.
Cabrera, C., Artacho, R., & Gimenez, R. (2006). Beneficial effects of green tea - A review. [Review]. Journal of the American College of Nutrition, 25(2), 79-99.
Sarma, D. N., Barrett, M. L., Chavez, M. L., Gardiner, P., Ko, R., Mahady, G. B., et al. (2008). Safety of green tea extracts - A systematic review by the US Pharmacopeia. [Review]. Drug Safety, 31(6), 469-484.
Dunford, M., Doyle, J.A., (2008). Nutrition for Sport and Exercise. Belmont, CA: Thomson Wadsworth