Recent lawsuit threats against RJR-Nabisco visavie Oreo brand and concern about fried canola oil and the McDonald's "documentary" Supersize Me bring into stark concern dietary events about which Americans ought concern themselves. Contrary to popular myth however, these substances are not what fearmongers tout them to be. See an earlier post of mine.
The biggest problem as I see it is that trans fats interrupt the normal fat metabolism process and retard the body's ability to use fat or mobilize it to the body. Muscle cells primarily burn glucose/glycogen (glucose polymer) and so when they exhaust those sugar stores, the body mobilizes fat to the site of muscle contraction so that muscles can burn them. The heart, by contrast, and other non-muscle cells, can burn fat directly by the process of β-oxidation which cleaves off the ends of fatty acid chains directly into acetyl-coA which feeds the Krebs/Citric Acid Cycle for electron transport and ATP production.
Normal operating procedure assumes that the following mechanism is possible:
β-oxidation of unsaturated fatty acids poses a problem since the location of a cis bond can prevent the formation of a trans-δ2 bond. These situations are handled by an additional two enzymes. The problem with this process is that it occurs in the peroxisome, and instead of yielding ATP as a product the high-potential electrons are transferred to O2, which yields H2O2.
The biggest problem with peroxidation is that it involves the introduction of free radicals which can steal electrons from any substrate, particularly damaging to DNA and cell membranes. It is believed that this process is utilized in the metabolism of polyunsaturated fatty acids, which are not normally converted to energy, being instead fit substrates for tertiary adjunct molecules like hormones and neurotransmitters, being in themselves chemical structures for the creation of which animal cells lack appropriate enzymes. In extreme duress, however, they will be cannibalized by this process for energy.
Trans fats can only be digested using the peroxidation event. Normal β-oxidation proceeds until the enzymes cannot properly access the trans substrate, being as how its spatial arrangement prohibits the normal metabolic process. The digestive apparatus abandons that capped chain for another. For a human, this might result in a series of fatty acid chains than cannot be digested under normal processes without oxidative damage through peroxidation, and under normal conditions the body will not peroxidize unless absolutely necessary.
In my opinion, this accounts in part for the prevelence of "stubborn belly fat", seeing as how the deposits encircling the abdomen might contain a myriad of fatty acid chains containing trans-fats which cannot be metabolized by normal activity. Overall the most efficient way to remove them is via liposuction, since the vacuum holds no bias for cis-bonds or saturated fat and sucks it out irrespective of its location in a chain. However, that's somewhat counterproductive as the process induces starvation responses, resulting in subsequent fat accumulation post-operation, meaning that without a change in diet, the fats will quickly redeposit as if the procedure had never occured.
Exercise plays the major role. With increased metabolic demand through intensive aerobics and strength training, the muscles can be starved continually of glycogen and forced to utilize mobilized fat. As demand increases, peroxidation will overcome the truncated fat metabolism and open up chains to normal β-oxidation past the constraint. Activity must be of both sufficient duration and intensity so as to train the body to utilize uncommon but available sources of energy.
Upon successful depletion of fat stores, special care must be taken. Maintenance of the activity level will help ensure that fat stores are prepped for consumption immediately rather than interminably deposed at the abdomen. Changes in diet that reduce or better eliminate trans fats will help prevent the future necessity of peroxidation as a means to terminally reduce fat stores and make progress against the stubbord stand of fat and allow one to trim down.
In the end, if you want to trim down, you must burn fat as a major portion of your calories. Even as you strengthen muscles, most of them lie obscured by fat deposits, so a muscular person with lots of fat will look just as bad as a flabby couch potato. Burn the fat, and people will be able to see your underlying definition.
Then lay off the Lays.
No comments:
Post a Comment