|MadSci Network: Biochemistry|
Aloha, Kim, First, let me answer your main question about coconut oil promoting weight loss. The answer is 'no.' The only thing that promotes sustainable weight loss is cutting kilocalories (energy intake) or increasing exercise or both. Actually, the best way to lose weight is to cut the calories a bit and increase exercise both...and to make permanent behavior changes in diet/exercise so you don't go back to living the way you did while you gained the weight. Now, on to your collary comments coconut oil being the 'fattiest,'the healthiest,' etc. Neither descriptor really fits coconut oil (or any other oil, necessarily). Let me use some of the information that I usually include in my 'Lipid' lecture for my introductory nutrition students, here at the University of Hawaii/Manoa, to explain why I have made those statements. Coconut oil is a liquid lipid. Most of the fatty material in coconut oil is in the form of triglycerides, just as in all other vegetable oils and animal fats. The chemical structure of triglycerides is one molecule of glycerol (-glyceride) with three fatty acids (tri-) hooked on. Where coconut oil has sometimes gotten a 'bad rap' is that most of the fatty acids are what are called 'saturated'(chemically, where there are all single bonds between adjacent carbon atoms in the long-chained molecule). This type of fatty acids in diets seems to be related to a higher risk for developing one of a number of chronic diseases (like cardiovascular disease...heart attacks). The saturated fatty acids, when they become part of the cell membrane and other cellular structures, seem to produce 'stiffer' membranes...less flexible. The remainder of the fatty acids in coconut oil(about 10%) are either monounsaturated or polyunsaturated (chemically, where there are one or more double bonds between carbon atoms in the chain). Some other plant oils (olive oil, canola oil, corn oil, etc.) have much more of the mono/polyunsaturated fatty acids...and some research suggests that populations who use these types of lipids have less of a risk for developing some of the chronic diseases...so these oils might be considered more healthful than coconut oil. Also, unless you eat a lot of highly processed/fabricated foods OR belong to cultural groups (like Samoan and some other Pacific Island populations) who use a lot of coconut oil and other coconut products as part of their ethnic cuisine, most of us don't get a lot of coconut oil (or other tropical oils) in our food. As a Ph.D.-level nutritionist (and a real lover of food, too), I think all the emphasis on the KIND of lipid is a bit misplaced. Lipids ARE one of the major classes of nutrients...we can't live/grow/reproduce without them in our diet. However, since fat/oil all contains about 9 kcal/g (as opposed to 4 kcal/g for each protein and carbohydrate), it is really easy to 'overeat' kilocalories when there is a lot of fat/oil in food or used in food preparation. So, my take-home messages are: 1. Coconut oil in small amounts is fine; there are other oils that might be more 'healthful' in the long-run, though. 2. Coconut oil is not the 'healthiest,' 'most nutritious,' 'fattiest,' etc. AND it is not conducive to helping anyone lose weight! 3. Perhaps most importantly, be aware of where fat/oils are in your food, and enjoy those foods in moderation. After all, it is the fat/oil that probably makes those foods taste so good, since fat/oil helps carry flavors/spices. If you are trying to lose weight, one strategy that works for some people is to cut down on fatty foods a bit...chose leaner meats, lower-fat versions of dairy products, less butter/margarine on breads, and fewer rich, creamy sauces on those good carbohydrate sources, like pasta, spaghetti, and potatoes.
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