“The aim of the legal action is to force the fast-food industry to “offer a larger variety to the consumers, including non-meat vegetarian, less grams of fat, and a reduction of size of their meals.”
– News quote, July 24, 2002
Wow… this is getting nuts. That Hirsch guy, who’s inundating the news with his lawsuit against fast-food restaurants, is adding yet another log to the anti-fat fire. (Not to mention bringing new meaning to “pass the buck,” but back to my point…) The media is all over it. After small strides toward a more well-rounded view of dietary fat, the witch hunt is again resuscitated. “Non-meat vegetarian”? “Less grams of fat”? Is that the right interpretation? What about soft drinks, milk shakes and zero-fiber white buns? Nah; it’s easier to blame the burger and treat fat as a singular evil entity.
Admittedly, fast food in general is the current media target but once again we see fats getting lumped together and demonized as the problem. As usual, we need to consider the source of the information. Or better stated, we need to consider all the sources of information on the subject. When it comes to dietary fat, something fishy has been going on for years – or should I say something not fishy enough.
I don’t know exactly how I became interested in dietary fat. I suppose it crept up on me in much the same way that research on dietary supplements and anabolic steroids did. The problem is, the predigested message reaching our ears has been interpreted by folks who are not bodybuilding-conscious. Many aren’t even health conscious. It’s easy for the media to make a specific point (and plenty of profit) by dredging-up scare tactics and controversy. We are literally told what to think and most of us are too busy or too unaware to object. The more we are told to demonize something, the easier it is to stop questioning it. But for some, the incessant media hype just hacks us off.
So here’s a question: Is there just one type of dietary fat? Clearly, the answer is NO. Of the many different kinds, we see a full medicine chest of dietary “drugs” (call them “nutraceuticals” if you will). And that’s not just my assessment.(4, 6, 7, 23) One of America’s problems is that – as is the case with many dietary components – we get no variety. Too much of any single nutrient isn’t good. And yet we gorge ourselves on french fries, chips, and other greasy modern delights. We can’t resist a good deep-fried refined starch. We end up consuming tons of omega-6 polyunsaturated fatty acids and trans-fatty acids rather than getting-in a healthy balance of omega-3s (DHA and EPA from fish oils, linolenic acid from flax), monounsaturates (olive oil, peanuts), and other interesting lipids. The goal for any physique and health-conscious individual should be to seek out and consume a greater variety of fats. I’ll warn you, though, it takes some work.
I think there’s been a whole grease trap of public confusion surrounding this issue so here’s a shotgun eight-point lipid biochemistry tutorial. It’ll be chewy for some, a mere reminder for others.
Table 1. Lipid Biochemistry Facts
1. Three fatty acids (long carbon chains) attached to a glycerol molecule (three carbon “backbone”) make a triglyceride. These fats are more accurately called “tri-acyl-glycerols.”
2. Triacylglycerols come from the diet (hitting the bloodstream packaged into “chylomicrons”), from adipose tissue storage (hitting the blood as free fatty acids bound to a protein called albumin and free glycerol), or from readily-oxidized intramuscular stores.
3. It’s the various fatty acids that are broken off (during “lipolysis”) and metabolized differently that result in effects varying from inflammation to muscle building.
4. Fatty acids with no carbon-to-carbon double bonds along their length are saturated fatty acids (the carbons are “saturated” with hydrogens). Fatty acids with just one double bond are mono-unsaturated and fatty acids with multiple double bonds are poly-unsaturated. Saturated fatty acids are generally solid at room temperature (lard, butter, etc.) while polyunsaturates are liquids (corn oil, soybean oil, etc.) Makes sense, right?
5. The terms omega-3 or omega-6 simply mean that the first double bond of the fatty acid is either three or six carbons away from the (methyl) end of the chain, respectively.
6. We mammals have the ability to elongate and desaturate fatty acids in our cells. That is, we can make our own versions of fatty acids as needed from other sources. We only have the enzymes to do so up to a point, however (these enzymes are named delta-4,5,6 and 9 desaturases for those who care). Thus, we need to get “essential” fatty acids from our diets.
7. Linoleic acid (18 carbons long, two double bonds at 9 and 12 positions; omega-6 type) and linolenic acid (also 18 carbons long, three double bonds at 9, 12, and 15 positions; omega-3 type) are essential fatty acids.
8. Trans-fatty acids are generally produced for industry (e.g. margarine) by bubbling hydrogen through natural “cis-” fatty acids. These trans fats have hydrogen atoms on opposite sides of the carbon-carbon double bond rather than on the same side as naturally occurring cis-fatty acids do.
Okay, sorry for the lecture there, but we needed to get a few things straight before tackling bigger things (like how we can benefit from increasing certain lipids in our diets and why many authorities incorrectly blame dietary fats for what ails us). With 90 percent of Americans trying to cut down on “fat” (14), it’s time for some mental floss.
One of the fishiest things about the way media mongers demonize fat is the seemingly selective attention paid to the published literature. First and admittedly, it is true that the total amount of fat consumed by people is correlated to certain cancers and other diseases.(13) Yet we’ve already seen how widely fats differ. Can we really lump them all together? In one sense, perhaps, but we should remember that they not only differ in structure, they differ vastly in their physiologic effects.
Let me continue my conspiracy theory by unveiling a little known controversy over animal fat. Decades ago, two investigators named Brown and Goldstein explained how saturated fat wreaks havoc on our cholesterol levels. They were right, of course, but their research ignited a witch hunt. Authorities now almost universally condemn animal fat when it comes to heart disease and cholesterol elevation. In fact, I’ve worked in a major medical institution where the terms “animal fat” and “saturated fat” have become essentially interchangeable. Hmm. Well, here’s an interesting fact: less than half the fat in meat is saturated. And there’s more. Of the saturated portion in meat, one of the most common fatty acids has negligible impact on cholesterol. It’s been known for ages.
Stearic acid (18:0), prevalent in beef, lacks the hyper-cholesterolemic qualities associated with its brethren.(1, 9, 11) And diets rich in stearic acid don’t affect the clotting tendency of blood compared to the typical American diet, either.(12) Add grass-fed beef (richer in CLA and lower in omega-6 fats) and specialty eggs containing DHA (“fish oil”) to the list and you have to wonder how certain experts can prefer common (generally omega-6) vegetable oils. The trend for Americans to eat less red meat (22) and have less access to animal fat in the food supply (18) is hardly beneficial considering they replace it with vegetable oils in true junk foods (17, 18). That practice is, in many ways, far worse for their health. Yet many authorities make it sound like we’ll have to sign a waiver just to eat a juicy steak.
And what about fish oils? After years of data accumulation, only now are they accepted as essential enough to be included in infant formulas, for example. Babies who get them out-perform their peers on both physical and mental tasks. Adults need them, too.
Unlike the Americans, the Canadians clued in a while ago with their 1990 recommendations (RNI) on proper “omega-6: omega-3 ratio” (6:1). This official advice suggested 0.55 g of omega-3 fats and 3.3 g of omega-6 fats per each 1000 kcal of intake. It was definitely a step in the right direction for them.
Not all authorities are progressive enough to really get behind such a position, however. I’ve got a knee-high stack of studies in my office on omega-3 benefits; anyone can see there’s something going on. Anti-inflammatory, anti-thrombotic (anti-clotting), anti-hypertensive, anti-atherogenic, anti-diabetic, anti-depressive, anti-catabolic – sounds like just what Americans (especially certain bodybuilders) need! Sure, there’s always some equivocality to research but look at the volume of epidemiological studies, clinical trials, and evolutionary evidence. How can such compelling and independent substantiation be swept under the rug while cardio-protective honors have been fast tracked at soy? Obviously, social trends affect our conclusions.
And to continue my rage against the machine, I’d like to point out that high fiber, low-fat diets actually suppress Testosterone levels.(5, 8, 19) They’re blaspheme – at least for the struggling bodybuilder. Changes can occur in as little as two weeks!(18) Munching your corrugated bran puffs and feeling good about your anti-fat discipline is getting your physique nowhere. Lemme turn on that “Lifetime channel” for you, girlie man; you won’t be feeing much like lifting heavy anymore. (Okay, so I’m not about to condemn fiber but such studies do support fat’s necessity.)
Now then, what’s the problem with all those omega-6 fatty acids in our diets? Doesn’t our eight-point review say they’re essential? Well, yes – but although essential for human health (omega-6 fats serve as precursors for necessary eicosanoids, etc.), we definitely get too much of a good thing. The sheer amounts inundating our modern diets are unlike those that humans evolved to process. As I alluded to earlier, “naturally” grazing animals have a much lower omega-6 to omega-3 ratio in their meat than do modern corn-fed livestock.
Call it the price for depending on agriculture (which of course we must). And where in nature does a hunter-gatherer find enough polyunsaturated oil to deep fry anything? For that matter, where are the “natural” deep fat fryers at all? We “killed and grilled” – while grazing on various plants. Them’s the facts, folks. By living on hydrogenated and omega-6 oils by the bucketful, we end up with low-grade inflammation, immune alterations, and other assorted maladies that are particularly disturbing to a health-conscious athlete. Our modern diet is an anomaly to our genetic blueprint – a blueprint that used to be successful.
By the way? yes, I am continuing to incriminate common polyunsaturated fatty acid (PUFA) oils. If you’ve been taught that these are “good” and that saturated fat is “bad,” you can now see that you’ve only been given half the picture. There are just so many kinds of each that one can’t make such categorical statements. That’s why I said common PUFA oils; less prevalent ones have all sorts of beneficial effects that we’ll discuss in Part II of this article.
Okay, last up in our discussion of dietary fat generalities: incorporating higher fat into one’s diet, and the subsequent adaptations that occur. Acute things first? Adding fat to a carbohydrate meal can enhance the insulin response while moderating the usual glucose “spike.”(3) Even if it’s just due to slowed gastric emptying, that sounds good for delaying fatigue and even for building muscle.
It stands to reason that because fat enhances both insulin and Testosterone concentrations in the blood, it should result in muscle gain. Indeed, researchers have seen improved nitrogen status (“balance”) in both rats and healthy adult men when feeding an isonitrogenous, isoenergetic (protein and calories held steady) carb-to-fat ratio of 1:1 compared to 2:1.(15, 16). That is, replacing some of one’s carbs with fat makes sense to the bodybuilder.
In fact, at least in rats, the effect appears linear with increasing proportions of fat up to double the carbohydrate portion.(16) Furthermore, these same researchers found that after six weeks, “rats fed the high-fat diet had the highest protein gain and the lowest fat gain as a function of energy intake.” And let’s not even get into the fact that many athletes get too few calories anyway, and adding some healthy fat is an easy way to correct this (i.e. let one’s kcal ceiling slide up a bit).
Lastly, it should be pointed out that switching to a higher-fat diet is accompanied by metabolic benefits that look an awful lot like aerobic training adaptations.(2, 10, 20, 21) Although eating fat isn’t going to replace anyone’s “cardio,” you have to admit that’s pretty interesting.
So here’s our summary of Part One:
1. Despite a ton of existing literature to the contrary, the official professional and media consensus is often that dietary fat (as if it were a singular entity) is largely at fault for America’s pathetic health status.
2. In truth, it’s the type of fat and how we ingest it – not just the total amount – that’s our problem. Although newer dietary recommendations acknowledge this, the media apparently doesn’t.
3. It’s the combination of other deleterious health habits (e.g. high-refined carb intakes, zero activity, etc.) that confound the public’s understanding of dietary lipids.
4. Different dietary fats have been likened to drugs more than once because of their potency in affecting human physiology.
5. Humans are highly adaptable organisms and just a few weeks on a higher-fat diet starts hormonal, immune, enzymatic, muscular, and many other changes that seem to lead to muscle gain, less body fat and adaptations similar to aerobic training.
To conclude Part I, I’d like to point out that I’m not a high-fat diet fanatic; carbs definitely have their place on an athlete’s table. What I’m trying to do is unveil the oft-ignored side of the coin. Let’s restate that media quote in more accurate terms for the physique-conscious person:
“…offer a larger variety to the consumers, including higher quality meats, less grams of hydrogenated and omega-6 fat, and a reduction of the amount of refined carbohydrate in their meals…”
Now that’s a bit better – but it’s going to be a long time before the establishment is willing to stop the witch hunt.
1. Ahrens, E., et al. The influence of dietary fats on serum lipid levels in man. Lancet 1: 943-953, 1957.
2. Andersson, A., et al. Effects of physical exercise on phospholipid fatty acid content in skeletal muscle. Am J Physiol 274(3 Pt 1): E432-438, 1998.
3. Collier, G. and O’Dea, K. The effect of coingestion of fat on the glucose, insulin and gastric inhibitory peptide responses to carbohydrate and protein. Am J Clin Nutr 37: 941-944.
4. De Catarina, R., et al. n-3 fatty acids and cardiovascular disease: Update to 1996. G Ital Cardiol 26(5): 563-578, 1996.
5. Dorgan, J., et al. Effects of dietary fat and fiber on plasma and urine androgens and estrogens in men: a controlled feeding study. Am J Clin Nutr 64(6): 850-855, 1996.
6. Endres, S. n-3 polyunsaturated fatty acids and human cytokine synthesis. Lipids (Suppl): S239-S242, 1996.
7. Fauconnot, L., et al. Gamma linolenic acid biosynthesis: cryptoregiochemistry of delta-6 desaturation. J Org Chem 66(4): 1210-1215, 2001.
8. Hamalainen, E. Decrease of serum total and free testosterone during a low fat, high fiber diet. J Ster Biochem 18(3): 369-370, 1983.
9. Hegsted, D., et al. Quantitative effects of dietary fat on serum cholesterol in man, Am J Clin Nutr 17: 281-295, 1965.
10. Jaya, T., et al. Influence of the level of dietary lipid intake and maximal exercise on the immune status in runners. Med Sci Sports Exerc 29(3): 333-344.
11. Keys, A., et al. Serum cholesterol response to changes in the diet Metab 14: 776-787, 1965.
12. Kris-Etherton, P., et al. Effects of dietary stearic acid on plasma lipids and thrombosis. Nutr Today 28(3): 30-38, 1993.
13. Kuller, L. Dietary fat and chronic diseases: epidemiologic review, J Am Diet Assoc 97: S9-S15, 1997.
14. Matte, R. Position of the American Dietetic Association: fat replacers. J Am Diet Assoc 98: 463-468, 1998.
15. McCarger, L., et al. Dietary carbohydrate-to-fat ratio: influence on whole-body nitrogen retention, substrate utilization and hormone response in healthy male subjects. Am J Clin Nutr 49:1169-1178, 1988.
16. McCarger, L., et al. Influence of dietary carbohydrate-to-fat ratio on whole body nitrogen retention and body composition in adult rats. J Nutr 119: 1240-1245, 1989.
17. Popkin, B., et al. Where’s the fat? Trends in US diets 1965-1996. Preventive Medicine, 32(3): 245-254, 2001.
18. Raper, N., et al. Nutrient content of the US food supply, 1909-1988. USDA Home Econ Res Rep. 50, 1992.
19. Reed, M. Dietary lipids: An additional regulator of plasma levels of sex hormone binding globulin. J Clin Endocrinol Metab 64(5): 1083-1085, 1987.
20. Rowlands, D. et al., Effects of high fat and high carbohydrate diets on metabolism and performance in cycling. Metab 51(6): 678-690, 2002.
21. Stepto, N. Effect of short term fat adaptation on high intensity training. Med Sci Sports Exerc 34(3): 449-455, 2002.
22. http://www.usda.gov/news/pubs/fbook98/ch1a.htm; 1999 accessed Aug. 2002.
23. Watkins, B., et al. Nutraceutical fatty acids as biochemical and molecular modulators of skeletal biology. J Am Coll Nutr 20 (5 Suppl): 410S-416S, 2001.