"Melt away the fat," "It Will Burn the Fat Right Off You," "Ignite Your Metabolism"....Sometimes I can't tell if someone if supplement companies want you to lose weight or start a forest fire. Some of the hottest (pun intended) new supplements on the sports nutrition scene are weight loss supplements aka fat burners. As usual, it's difficult to sift through the marketing strategies and to decipher if these products really work. In theory, these products are typically designed to either A) Increase your metabolic rate or B) Increase lipolysis or the breakdown of fat stores. Believe it or not some fat burners have actually been shown to be successful. There is some evidence that shows elevations in one's metabolic rate following the ingestion of these metabolic stimulants or thermogenics as their often called.
Now some of the above mentioned alterations in thermogenesis (the production of heat within the body) and lipolysis (fat breakdown) can be achieved through diet alone. One way to go about this is by consuming foods that seem to induce thermogenesis such as spicy foods. We've all experienced this before right? Pop a couple of jalapenos and before you know if you're breaking a sweat just by eating! However it may not be enjoyable to walk around all day eating peppers like they're candy. Other food products that seem to have a thermogenic effect are those containing high amounts of protein. Research has shown that protein ingestion may increase energy expenditure by roughly 10% (the increase is energy expenditure is due to the increased energy needed to digest protein). My brother used to always joke that after a nice 72 oz. steak he would get "The Meat Sweats." It appears as though he was on to something. However, this concept should be taken with a grain of salt; and no it's not to make your steak taste better. If protein ingestion can increase energy expenditure, it doesn't mean that those extra calories burned will off-set that 72 oz. steak you just ate. It's important to remember that just because your body is experiencing a thermogenic enhancing effect, doesn't mean that your going to lose weight just by eating those foods. You still need to be burning more calories than you are consuming to lose weight. Another way to manipulate fat burning within the body is maintain low insulin levels. When insulin levels are high, as is seen with diets high in sugar, fat breakdown is inhibited. This concept is the backbone of diets such as The Atkins Diet and Nutrisystem's Diet of Glycemic Control. This is also the reasoning behind doing your cardio (low intensity only) in the morning before you've had breakfast; low insulin levels will promote a greater utilization of fat as energy during your workout.
So now on to the important stuff, fat burners, do they really work? And the short answer is: probably not to the extent we are led to believe. Some thermogenic products have been shown to increase energy expenditure by up to 10-40% upon ingestion as well as decrease body fat percent by 1-3% after long-term supplementation. The main ingredients in these products are typically caffeine, green tea extract, Chromium, B-Vitamins, L-Carnosine, Ketones and usually a variety of other herbs. The ingredients that seem to be the most effective, in terms of increasing metabolic rate, are caffeine and green tea extract. There used to be another popular ingredient that was very effective but unfortunately was banned by the FDA as it was "linked" to some "adverse events" (I think it was wrongfully banned). This ingredient was known as ephedra and was a staple in many weight loss products, Hydroxycut (the original patented formula) being one of them which is why it WAS so effective. The problem with a lot of weight loss products is that they combine several ingredients together into one formula without really understand how they will interact with each other. Luckily, these ingredients are in such low dosages that they probably don't even have any effect on the body at all. However, I advise caution when selecting these products and make sure you read the label and know what you are consuming. If you wanted the cheapest, safest and most effective product, you're best bet is probably caffeine pills. They are low in calories, cheap and caffeine is probably the most effective metabolic stimulant. Green tea extract would be my next choice. Green tea extract not only has caffeine in it but also several anti-oxidants and health promoting ingredients.
There really isn't a lot of research that tells us about how effective and safe these products really are over extended periods of time. Most studies just show acute elevations in energy expenditure. Therefore it's difficult to speculate whether or not these products would be successful at promoting weight loss after years of supplementation. Below is a list of the most effective fat burner ingredients as well as literature that supports the use of some of these thermogenics.
Top 4 Fat Burner Ingredients:
1) Ephedra
2) Caffeine
3) Green Tea Extract
4) Synephrine
http://www.jissn.com/content/4/1/10/abstract
http://www.jissn.com/content/6/1/4/abstract
http://www.jissn.com/content/6/1/1/abstract
http://www.jissn.com/content/5/1/19/abstract
And of course, there is the easiest, cheapest and most effective method of burning fat and increasing energy expenditure: EXERCISE
