View Full Version : Dietary Fat
03-22-2007, 06:52 AM
Ok, someon give me a decent explanation of what happens with dietary fat in the diet. Supposedly it is hormonally neutral so it doesn't trip insulin but what actually happens in your body when you, say, eat more than an optimum amount in a 40/30/30 macro ratio?
03-22-2007, 10:04 AM
IMO the 40-30-30 ratio is a good starting point, not the optimum. In the second PM I really hash this out... basically if one leans out on the base Zone using the 40-30-30 ratio one will then need to increase fat blocks between 2 and 5x to support activity level. This leaves the ratio at the 5x level at something like 15-25-60. That is obviously a huge difference between the baseline and athletes zone...and it tells me there is not an optimum fuel mixture other than what your individual needs are both with regards to genetics and performance needs. What the Zone does (in both base and AZ versions) is provide adequate protein and fats while heading towards an optimized carb intake. I think the carb intake can be further tweaked to match activity by putting most of the carbs in a post workout meal...but that is being covered in this months PM. So bottom line is the Zone is just "good", not magic.
Back to the question of the fate of dietary fat. Our body is in a constant state of flux. Tissue is rebuilt and turned over and dietary fat is used to build cell membranes and hormones...and it is utilized for energy. In general the body will preferentially utilize whatever fuel is most available. If we eat mainly carbs we will burn mainly carbs. Same story for fat. There are also hormonal consequences of what fuel is predominating in our diet. Too many carbs obviously pose a problem. Too much fat can also...but it's tougher to over do fat in the absence of carbs.
This paper from Nutrition and Metabolism talks about ketogenic diets and performance. The take home points are:
1-It takes time to adapt to a high fat diet.
2-Once adaptation has occurred performance is just as good as a high carb diet except for sprint activities.
3-This makes sense as fats can fuel brief explosive efforts an long slow efforts...but we need glycogen for thing like 400 and 800m runs and CF style metcons.
Here is that paper:
Let me know if this clears things up or makes it muddier!
03-22-2007, 12:47 PM
Do you mean when you eat fat vs. carb vs. protein, what actually happens when you eat the food?
Only eating carb makes me want to eat more, carb spike insulin, then I get hungry again. I notice this when I drink beer, I just can't get full on beer.
Where protein and fat have a filling effect that satifies my hunger.
03-22-2007, 12:51 PM
I think Frank means where does the excess fat go? Like excess carbs and protein (to a lesser extent) get stored as fat. Does excess fat get stored as fat?
That's what they told us 10-15 years ago; hence, low fat ice cream that my wife swears by. Shit made me fatter. Of course, I would eat like a gallon at a time.
My theory on excess fat (like fat from steaks, chops, eggs, bacon, cheese. . .now I'm hungy) goes right out the ol' pooper. Correct me if I'm wrong, so help me Walshy.
03-22-2007, 12:54 PM
The brain is also like 70% fat....so it likes fat in the diet....rebuilds and works better......as kids on seizures (like having 5-6 day), went on a high fat diet (which in today's world 30% is high fat) and whoolaa....most kids were down to 1 seizure a week...if any!
Cell membranes need dietary fat to rebuild, hormones need dietary fat....so any diet not getting fat...reduces cell membrane and hormone effectiveness....not too mention the wrong kind of fats (trans) will just harden up the cellular membranes and cause more health issues.
Fats when mixed with protein aid to slow down digestion....aka control blood sugar and insulin response.
As Robb says above...timing is key too as to how things are used....I'm all for the Protein and fats during the day with veggies (maybe some fruit am), but keep the bulk of carbs post workout where the anabolic role of insulin can be maximized. Plus it all depends on your activity level and what exercise you are doing...whether you need glycogen (which is essential for explosiveness in sports) or can get away with more dietary fat (more aerobic endurance related).
03-22-2007, 01:26 PM
Hmmm, that ratio Robb posted is roughly what mine has been lately. What happens if it goes higher? Obviously, if one eats too much of anything there are going to be effects from it. I'm interested in the hormonal response in this case more than anything else. Does the excess that can't be burned off, as Ron said, go right out the poopshute?
03-22-2007, 02:49 PM
Too much fat can also...but it's tougher to over do fat in the absence of carbs.
I think the answer you are looking for is right there....if your carbs are waayyy low, then dietary fat really won't go against you.....but if your carbs are higher and your fat is high....well you are not going to lose weight. But in my humble opinion you still need to replenish glycogen to be functional....hence the PWO meal.
As far as hormonal responses...well that will depend on the type of fat it is...sat, unsat, monounsat, polyunsat, etc. Mono and Sat are supposed to increase T levels. Fish Oil of course helps everything. Too much Poly-Omega6 will increase inflammation which will also go against your fat loss efforts. Also fat loss is anti-catbolic, as if you are breaking down muscle tissue for energy, then you are not burning fat. So make sure you are not doing anything to promote excess Cortisol.
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