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Bulletin #47 – Exploring The High Fat Diet

Over the last two or three years several “new”dietary strategies have been advanced whichare specifically designed to help bodybuild-ers get extremely lean for contests. Thesediets have in common a fairly high proteinintake, around 25-30% of calories. Anothercommon feature is that they advocate reduc-ing carbohydrate content in favor of increas-ing dietary fat consumption. Some of theseplans call for limiting carbs to 30-50 gramsper day, or even less, and providing around70% of calories from fat. This low carb regi-men is carried out over a five day (or so)course to deliberately induce ketosis and afat-burning metabolism, to promote the useof stored body fat as energy. This is followedby two or three days of carbing up to pro-vide an anabolic growth phase. Another pro-gram is more moderate, suggesting a diet of30% protein, 40% carbs, and 30% fat, with-out cycling. There is a lot of science andtheory behind these diets, although the highfat recommendation is quite controversial.Without getting too bogged down in the bio-chemical details, the fundamental idea be-hind these approaches is to reduce carbo-hydrate intake in order to reduce insulin lev-els. Insulin is a potent inhibitor of lipolysis,or fat breakdown.

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By reducing insulin levels(and, less importantly, by increasing gluca-gon) we can take the brakes off fat metabo-lism and encourage the use of stored bodyfat for energy.If you’re familiar with my work at all, you willknow that I advocate, in general, a diet highin protein, high in complex carbohydratesand very low in fat. I agree that hard-trainingathletes need more protein than sedentarypeople, at least one gram to 1½ grams perpound of body weight per day. You mightexpect me to flame the authors of these pro-grams (to borrow a little Internet jargon), butI’m not going to. These people all are veryknowledgeable about nutrition and have puta lot of thought and research into their pro-grams, and so have I. They all can point tonumerous examples of great success they’vehad with their programs, and so can I. Theyhave all worked with bodybuilders and havegenerated champions, and so have I. Sowho’s right?Nutrition is a fascinating field. It’s one of thefew areas of science where highly trainedexperts with vast clinical experience can com-pletely disagree about even fundamentalconcepts. This disagreement about funda-mentals suggests that nutrition science isstill in its infancy.

Why is nutrition still in itsinfancy? Because nutrition (at least optimumnutrition) is very complex. Let me explain.On one hand, nutrition seems ridiculouslysimple. If you just eat a fairly balanced diet,you will live and probably do okay. You don’teven need to know what a carbohydrate is.If you just get some food to eat, you prob-ably won’t have any problems. At anotherlevel, however, nutrition can get very com-plex. At this level, we’re not concernedmerely with sustaining life, but with promot-ing a state of optimal health, increased en-ergy, enhanced muscularity, and extremeleanness. At this level, nutrition becomesone of the most complex sciences there isbecause it incorporates every biochemicaland metabolic pathway in the body. We haveto know exactly how every nutrient is me-tabolized and how this affects cellular physi-ology. We have to understand how food af-fects hormones which in turn control fat andmuscle metabolism. At this level food is notmerely fuel thrown into the furnace, butrather the raw materials we use to sculpt ourbodies. To attain a truly top physique, suchas that of a champion bodybuilder, you willfind that nutrition is the most critical vari-able. It is the area where the most mistakesare made, because it is the most complicatedaspect of bodybuilding. At this level, every-one is training hard and heavy and usingproper technique. You won’t even get closeto a bodybuilding stage if you don’t trainhard.

All competitive bodybuilders knowhow to train. Whether you do an extra set ofincline flyes or not won’t make the differ-ence in if you win or lose the contest, butwhether or not you eat an extra bowl of ricethe day before the show very well could.Races are won or lost by a fraction of a sec-ond; bodybuilding shows can be won or lostby a bowl of rice.The point of this is not to get into argumentswith other experts on bodybuilding nutrition.The point is not to call people names or ex-change insults. The point of this is to figureout what is the best diet for bodybuilders(and anyone else, for that matter) to gainmuscle and lose fat and be healthy. I’m al-ways reading and studying to learn newthings, and I am receptive to new ideas andnew approaches. If the high fat, low carbapproach worked better, then I’d switchhorses.

So back to the basic question: Who’sright?The fact that some people have had successwith the high fat diet and that others (actu-ally the majority of bodybuilders) have hadsuccess with the higher carb diet proves thatboth approaches can work. So the answer tothe question is that both camps are right, atleast partially. How can two opposite ap-proaches to nutrition both give good re-sults? Does one approach give better re-sults? Is one approach healthier? Here’swhere the discussion starts to get compli-cated.Back in the early days, before there was aParrillo Performance, I tried all sorts of diets– everything you can imagine. High carbs,high fat, even a liquid protein fast withoutcarbs or fat (that didn’t work). I varied ma-cronutrient ratios (percent of calories fromprotein, carbs, and fat), food choices, mealfrequency, meal structure, protein only meals,carbs only meals, amino acid combinations,you name it. All the while I was chartingpeople’s body weight, body composition,and strength levels. I tried all sorts of vari-ous food combinations to see what wouldwork to help bodybuilders lose the lastounces of fat. During this time I read everymedical book I could find about nutrition,protein metabolism, and fat loss.

Throughmany years of experimentation and plain oldtrial and error, I arrived at the Parrillo diet,now published as the Parrillo NutritionManual, as being the diet which simply gave the best results for most bodybuilders.So how can two very different approachesto bodybuilding nutrition (high fat versuslow fat) both give good results? One thing Ifound during my years of experimentationwas that different body types respond some-what differently to different nutritional struc-tures. There are three very general bodytypes, classified by general appearance.Ectomorphs are naturally skinny people,mesomorphs are naturally lean and muscu-lar, and endomorphs are naturally fat. (Youknow which you are.) Obviously,mesomorphs have the easiest time becom-ing bodybuilders. These are the people weall envy. They were lean and muscular be-fore they ever started training. They gainmuscle easily. They can eat like crap and stilllook good. All they have to do is cut thejunk out of their diet a month before the showand they’re in contest shape. If you’re anectomorph or an endomorph you can stillbecome a good bodybuilder, but it will beharder because you’re working against yournatural genetic tendency to be either skinnyor fat.Ectomorphs get lean easily but have a hardtime putting on muscle.

They can eat a lotand don’t gain much weight. I found thatthese individuals do better on a high carbdiet with moderate to high protein, maybesomewhere around 25-30% protein, 65%carbs, and 5-10% fat. (The actual percent-ages aren’t important, but they usually workout close to those above. These are givenjust as an example.) Basically, they need toget one to 1.5 grams of protein per pound ofbody weight per day, and then keep increas-ing carbs until they gain weight. The prob-lem with using conventional fats for weightgain is that when your body is in a caloriesurplus (gaining weight) virtually all excessfat calories you consume from food will sim-ply be stored as body fat (1-13). Ectomorphswill find that adding some fat to their dietswill help them gain weight, but they’ll gainmore fat along with the muscle than if theyhad followed a low fat diet. It is extensivelydocumented in the medical literature thatexcess feeding of carbohydrates results inless body fat gain than excess feeding ofdietary fat (1-13).Endomorphs gain muscle more easily, butare naturally fat and have a hard time gettinglean. They seem to be very sensitive to thecarbohydrate content of the diet.

Again, forweight gain the body must be in an energysurplus (excess calories) and the bulk ofthese excess calories should come from car-bohydrates, because this results in less bodyfat accumulation than if the excess dietaryenergy is supplied as fat (1-13). However,during weight loss I found that these peopledo better if they reduce their carbohydrateintake. While ectomorphs need to maintaina high carb diet even while losing weight tohelp prevent muscle loss, endomorphs justcan’t seem to lose all their fat without reduc-ing carbs. They seem to be very sensitive toinsulin, and high insulin levels block theburning of stored body fat for energy. (Tobe more precise, they usually have mild in-sulin resistance, which results in increasedinsulin levels and a hard time burning fat.)Just as an example, some representative num-bers for an endomorph might look like this:For weight gain, 30-40% protein, 50-60%carbs,         5-10% fat. For weight loss, 50-60%protein, 30-40% carbs, 5-10% fat. Again, it’snot the actual percentages that are impor-tant, I’m just trying to illustrate the idea thatyou can shift around the structure of yourdiet to achieve different metabolic effects.Changing the ratio of protein to carbs to fatin your diet can have a big effect on the in-sulin-glucagon axis and nutrient partition-ing.On the Parrillo Nutrition Program you startby calculating your daily protein require-ment. One to 1.5 grams of complete proteinper pound of body weight each day is a goodgeneral guideline for hard training athletes,especially during weight gain.

As you de-crease calories to lose fat, it helps to increasethis to as much as 1.5-2 grams per pound perday. The higher dietary protein intake helpsprevent catabolism of muscle protein duringenergy restricted diets. Next you allot 5-10%of daily calories to come from fat. The re-mainder of your calories come from complexcarbohydrates, which I divide into starches(potatoes, rice, beans, etc.) and fibrous carbs(vegetables and salad greens). You adjustcarbohydrate intake appropriately so thatyou’re either gaining muscular weight or los-ing body fat, as desired. So when you struc-ture your diet this way the percentages takecare of themselves. The times when I citevarious nutrient percentages as examples aremerely to illustrate how the balance of yourdiet can change as you’re working to achievedifferent goals.So I have found that reducing carbs doesindeed help to promote fat loss, especiallyin people who have a hard time getting lean.I don’t have a problem with that. The thing Idon’t like about the high fat diets is that di-etary fat is VERY prone to be stored as bodyfat.

I have literally dozens of research articlesfrom the medical literature demonstrating thisand explaining the biochemical reasons why.Several studies have even demonstrated thatbody fat percentage is more highly deter-mined by dietary fat intake than by calorieintake (1,2,3,4,6,8,9,10). This is a concept I’vebeen talking about for years. So my disagree-ment is not about reducing carbs – thatworks. My problem is with supplying somany calories as dietary fat. Not only doesdietary fat contribute more to fat stores thanprotein or carbohydrate (1-13), but dietaryfat (especially saturated fat) increases yourcholesterol level and increases your risk forheart disease.So how do we do the low carb diet at Parrillo?I’ve developed a very special energy supple-ment called CapTri® which allows you toutilize the power of the low carb diet withoutresorting to using regular fat as a foodsource. CapTri® is a specially engineeredfat with a unique molecular structure whichcauses it to follow a different metabolic routethan regular fats (14,15). It behaves more likea carbohydrate in the body, except that itdoesn’t increase insulin levels. This meansyou can use CapTri® in place of carbs todecrease insulin levels and shift your me-tabolism into a fat-burning mode. This is verysimilar to the strategy of the high fat dietsexcept without relying on conventional fatas an energy source. CapTri® has virtuallyno tendency to be stored as body fat, whichis in marked contrast to regular fats (14,15).

Regular fat is metabolized very slowly and isvery easily stored as body fat. CapTri® isburned (converted to usable metabolic en-ergy) very rapidly – in fact, as rapidly asglucose. This energy is used to fuel thebody, which spares protein and glycogen.Since CapTri® is rapidly and completelyused as fuel, this means it won’t be storedas body fat. (Of course, CapTri® does notdefy the laws of thermodynamics, and if youeat too many calories too fast you will gain fat, even if you’re using CapTri®. The pointis that CapTri® results in much less fat gainthan conventional foods, because relativelymore of the calories in CapTri® are immedi-ately converted to energy and lost as bodyheat.) Furthermore, fats like CapTri® havebeen shown to increase growth hormone lev-els, which will also stimulate fat loss andmuscle gain (16). So we use a high fat dietalso, except we use CapTri® instead of con-ventional fats because the heat generatedby CapTri® has a much greater effect of in-creasing metabolic rate and much less ten-dency to be stored as body fat (14,15). It’sthe low carb diet taken to the next level.Another key concept of the Parrillo diet ismeal structuring. By combining protein andfibrous vegetables and CapTri® with yourstarch at each meal you can greatly slow therate of release of glucose into the blood-stream.

This in turn decreases insulin levels,taking the brakes off fat metabolism. You willfind that by proper food combining you canstimulate a powerful fat burning effect with-out eliminating carbs from your diet.Let’s talk for a minute about the theory be-hind the high fat diet and try to clear up someof the confusing issues. You’re probablywondering how can the high fat diet and thelow fat diet both work to get bodybuilderslean? Because any and all energy deficientdiets will result in weight loss. It’s a directconsequence of thermodynamics. If youconsume less calories than you burn, you’lllose weight. Period. So a high fat diet and ahigh carb diet will both produce weight lossso long as an energy (calorie) deficit is main-tained. So to lose body fat we need to achievean energy deficit. There are many ways todo this. The best way is through a combina-tion of aerobic exercise and a modest reduc-tion of caloric intake. It is now well knownthat severe caloric restriction results in de-creased metabolic rate, muscle loss, and in-duction (turning on) of fat-storing metabolicpathways. This is the “starvation response”the body generates during periods of fam-ine to guard against starvation. By decreas-ing energy expenditure (metabolic rate) thebody’s fat supply will last longer.

And byrevving up the fat-storing pathways, oncefood becomes available again fat depots arepreferentially repleted to defend against thenext bout of famine. Therefore bodybuildersknow they should avoid drastic reductionsin calories, since this causes muscle loss andslows fat burning.Increasing aerobic exercise activity on theother hand has the benefit of burning fatwithout slowing metabolic rate. In fact, aero-bic exercise causes metabolic adaptationsthat make the body more efficient at burningfat. In general, it is advised that weight lossbe limited to about one pound per week. Ifyou lose weight faster than this you will bemore likely to lose some muscle along withthe fat. Since one pound of body fat con-tains 3,500 calories, to lose one pound of fatper week you need to achieve a calorie defi-cit of 500 calories per day (3,500 per week).You could do this by cutting 500 caloriesworth of food from your diet, or by doing500 calories worth of aerobics a day, or bysome combination of both. I’ve found thecombination approach works best for mostpeople. Try not to cut your caloric intake bymore than 10% below maintenance. (Yourmaintenance intake is the number of caloriesyou consume everyday to maintain constantbody weight.) A good rule of thumb is toreduce energy intake by 10% below mainte-nance and then do enough aerobics to meetyour 500 calorie deficit for the day.

For ex-ample, if you normally eat 2,500 calories aday, cut that down by 250 per day (10%) anddo 250 calories worth of aerobics a day (that’sabout 30 minutes on a stationary bike). Thatequals a deficit of 500 calories a day, enoughto lose one pound of fat per week. This strat-egy is not an absolute rule carved in stone,but is a good general guideline that workswell for most people. Other people do bettersimply by increasing aerobic exercise with-out reducing calories. With a little experienceyou’ll find what works best for you.If your weight loss plateaus it is better ingeneral to do more aerobics rather than fur-ther reducing calories, because that will likelyslow your metabolic rate and thus your rateof fat loss. From body composition studies(use the Parrillo BodyStat Kit) calculate howmany pounds of fat you have to lose, andthat’s roughly how many weeks your dietwill last. If you need to lose more than 10pounds of fat (the diet will last for more than10 weeks) plan on taking a couple of weeksoff your fat loss diet after every 10 weeksand gain a pound per week. This will helpyou put on some muscle and boost yourmetabolism and get fat loss going again. Ingeneral, it doesn’t work too well to maintaina continuous energy deficit for more than 10weeks because your body adjusts to thisnew level of caloric intake and your metabo-lism slows down.

This reduced level of in-take will eventually become your new main-tenance if you stay on it too long.All right, so now we’ve decided to lose somefat and that we’re going to do more aerobicsand very modestly reduce calories. Now youhave some choices to make, and things canget complicated. We could simply reducecalories across the board – a 10% reductionin protein, carbs, and fat will obviously equala 10% reduction in total calories. Or alterna-tively we could alter the ratios of protein,carbs, and fat in the diet. As you reduce ca-loric intake, you should supply relativelymore of your calories as protein to preventor reduce skeletal muscle catabolism. So yourreduction in energy intake should come fromcarbs or fat, but not protein. As we’re diet-ing to lose fat we still need at least one gramof protein per pound of body weight eachday, and 1.5 grams may be better. Onceyou’ve decided on your protein intake thequestion then becomes should you supplythe remainder of your dietary energy require-ment as carbohydrate, fat, or some combina-tion of both. Any of these approaches willresult in weight loss, provided you maintainyour calorie deficit.

Which approach willwork best?The VAST majority of medical research indi-cates that a low fat diet achieves better fatloss results than a high fat diet (1-13). Sev-eral studies even show that reduction of di-etary fat content is as important, if not moreimportant, than reducing caloric intake. No-tably, and in fairness to the high fat diet, Ihave not seen any formal medical studiesusing diets comprised of approximately 70%fat and essentially no carbs. I imagine doc-tors are reluctant to carry out clinical trialsusing a diet so high in fat out of concern forit’s attendant health risks. Most of the medi-cal clinical trials comparing diets still includea significant carbohydrate load even in their“high fat” protocol, so they’re not reallycomparable to the extremely high fat – lowcarb diets which are currently being ad-vanced for bodybuilders.So what’s going on here? By reducing carbs to near zero levels (5-10% of calories per day)insulin production decreases dramatically.This eliminates its inhibitory effect on lipoly-sis. Human body fat is stored in the form oftriglycerides in fat cells (adipocytes). Releaseof fatty acids from fat cells is controlled byenzymes called lipases, which break downthe triglyceride into free fatty acids and glyc-erol. Once released from fat cells, the fattyacids are bound to a serum protein calledalbumin and transported in the blood to theliver and muscles where they are used forenergy. The lipases are activated by the cat-echolamines epinephrine and norepineph-rine (adrenaline and noradrenaline) which arereleased by the adrenal glands and the sym-pathetic nervous system.

The most impor-tant activator of lipolysis is release of nore-pinephrine by the sympathetic nervous sys-tem. Lipolysis turns out to be the rate limit-ing step in fat catabolism. (The rate limitingstep in a metabolic pathway is the sloweststep, which acts to limit the rate of the over-all pathway. It also is frequently the key pointof metabolic control for turning the pathwayon or off.) The catecholamines, in turn, arereleased when blood sugar gets too low andduring exercise. Another lipase is activatedby glucagon, which also promotes fat burn-ing. Glucagon is a hormone produced by thepancreas which has essentially the oppo-site actions of insulin. Insulin promotes glu-cose transport into cells, promotes the useof glucose as energy, promotes storage ofexcess glucose as glycogen, promotes trans-port of some amino acids into cells, promotesprotein synthesis, promotes fat synthesisand storage, and prevents fat breakdown.Insulin is released from the pancreas whenblood glucose levels are high, such as aftera meal, and acts as a storage hormone pro-moting storage of nutrients as glycogen,protein, and fat. Glucagon is released whenblood sugar levels are low, with the primarypurpose of increasing blood glucose levelsto provide fuel for the brain. Glucagon stimu-lates breakdown of glycogen and release ofglucose into the bloodstream, fat breakdown(lipolysis) and release of fatty acids into theblood (this use of fat as energy helps spareglucose for the brain), and protein break-down with release of amino acids into thebloodstream which can be converted intoglucose by the liver.

So lipolysis and the use of stored body fatfor energy is controlled by lipases which arein turn stimulated by catecholamines andglucagon. Glucagon turns out to be a minorplayer since virtually all of the glucagon re-leased by the pancreas is retained by theliver, and essentially none escapes into thegeneral circulation to reach peripheral fatdepots. (The small amount of glucagonwhich reaches adipose cells is too low inconcentration to have an effect.) So gluca-gon is primarily concerned with glycogenand fat metabolism in the liver. These samelipases that govern fat loss are inhibited byinsulin, which means if insulin levels are highyou won’t be able to use body fat for en-ergy. The high fat diets take this strategy tothe extreme by virtually eliminating carbo-hydrates from the diet in order to minimizeinsulin levels. The body can only storeenough glucose (as glycogen) to last aboutone day, so by eliminating carbs from thediet you force the body into a fat burningmode.Our discussion is far from over. Next monthI’ll dig deeper into these diets and show youwhy I believe bodybuilders who want thebest results possible should be eating a low-fat, moderate- to high-carb diet.


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