I know it's been discussed a million times, but wtf??? - macros vs. calories

[brihead301]

It is a given that in order to gain weight, you need to take in more calories then you use, and vise-versa for losing weight (take in less calories than you use). That is non-debateable. So I could eat 2000 calories/day of ice cream, and still lose weight if I was expending 3000 calories per day. That I understand perfectly fine.

What I really don't understand is how the macros come into play....at least regarding carbs and fats. We all know that protien is the main ingredient for muscle building...and the general consensus is that one should take in 1 gram protien/lb. of bodyweight.

Okay, so we are all pretty much in agreement that no matter what ones goal is - either to gain weight or lose weight, while being a gym-rat like us here at WBB, we should consume 1 g/lb. of bodyweight of protien daily, and eat either more calories or less calories then maintainence depending on whether the goal is to gain or lose weight respectively.

So if that is the case, what does it matter if the remainder of the daily calories come from carbs or fat? Even further, what does it matter if the source of carbs happens to be from vegetables or table sugar? Fish oil or bacon grease for fats? This is the part I just don't understand.

Basically, hypothetically speaking if I were 180 lbs. and trying to get ridiculously ripped by cutting down to 165 lbs, and my daily caloric requirements were 2000. What would it matter if I ate 720 calories worth of protien along with 1280 calories worth of table sugar vs. eating 720 calories worth of protien along with 1280 calories worth of brocolli vs. eating 720 calories worth of protien along with 1280 calories of fish oil vs. 720 calories worth of protein along with 1280 calories of a mixture of carbs and fats.....and so on?

Is there a link to an article that has the answer to this question? Google searches still haven't given me a clear-cut answer to this question.

Thanks!

[JSully]

You can still get fat eating below maintenance calories. If you don't fuel your body with the correct foods, you'll burn protein and add fat. The scale will get lower, but your bodyfat will get higher.

This is all from my experience, so take that for what it's worth. I'm 281lbs @ 19% bodyfat. I cut down from 299lbs @ 26% bodyfat in about 9 months. I've added 7lbs lbm and increased most of my lifts I focused on. My bench and squat went down, but my push press, clean, snatch and deadlift all went up. As did all my throws. No, I'm not lean, but my performance and strength has increased while dropping 20lbs. I only dieted for 4 weeks at a time, then maintainned for 3-4 weeks. Its simpler this way for me. Yes, I could get cut faster if I wanted, but I want performance over asthetics.

You should be having some sort of protein with every meal. IMO, you should not have carbs after 6-7pm, depending on when you go to sleep. Carbs break down to sugar in the form of glucose. Glucose is used for fuel. Glucose causes an increase in insulin which drives protein and carbs do your muscle to be used for energy. If you aren't doing anything that is going to use that energy, it's going to get converted and stored as fat to be used later. I've read a few places that when carbs are high, fats don't really do much besides get stored. But, they taste good and keep you sane. Obviously you need a mininum for hormone issues, but I don't worry about that. You need to figure out what works for you.

With that said, when in a deficit I keep my calories around 2700 (with a maintenance of approx 3700-4000). The macros I choose are 275p/275c/65f. When I am in my maintenance phase I'm somewhere around 300p/500c/85f with the bulk of my carbs in the morning and around my workout.

Here is a sample of my day while dieting (on a workout day, on off days I put my carbs at about 100g, therefore calories drop down to about 2400 or so). Please note, I don't know how great this is for BBing per se, but it has been great for performance.

breakfast = approx 75g protein & 50g carbs
lunch = approx 50g protein, 40g carbs, 10g fat
preworkout (about 45mins after lunch) = 100g carbs
*workout*
postworkout = approx 50g protein, 50g carbs
dinner = whatever is left over in protein and fats, typically 80-100g protein and 30-40g fat. (chicken w/ cheese & sour cream, cheeseburgers w/no bun, stuff like that)

You have to figure in trace proteins, carbs and fats as the above doesn't quite add up right, but you get the gist of things. On very strenuous days in the gym, I'll have less carbs with breakfast and more pre-workout.

So, in short, to answer your question BOTH are very important. FIRST figure out your calories to maintain. Then apply your deficit, then split your macros up to meet the calories. Vegetables are very fibrous and won't affect blood glucose levels as much as sugar will. You WANT sugar around your workout. Aside from around my training, I try to get a lot of fruits in just because I "feel" better eating fruits rather than getting a sodium bloat from ramen noodles. But it's all up to you really. IMO, you can still lose plenty of weight eating shitty carbs rather than healthy carbs, so long as they're timed right. In regards to fats, a fat is a fat IMO. I've eaten fish oil for dinner to make up fat and I've eaten In-N-Out double double protein style, still lost weight without an issue.

I don't have a link, I'm sorry. I'm just going by the hundreds of hours researching as well as my own personal experiences. If anybody wants to call me out to provide documentation, I'm not going to do it so don't waste your time.

[BallsWideDeep]

what does it matter if the remainder of the daily calories come from carbs or fat?

Within reason, I agree. As long as it's good fat I often eat higher than than the "recommended" amount.

Okay, so we are all pretty much in agreement that no matter what ones goal is - either to gain weight or lose weight, while being a gym-rat like us here at WBB, we should consume 1 g/lb. of bodyweight of protien daily, and eat either more calories or less calories then maintainence depending on whether the goal is to gain or lose weight respectively.

I disagree. The metabolic benefit alone makes at least 1.5g/lb. worth while. That's assuming your diets calories can accommodate it..

Basically, hypothetically speaking if I were 180 lbs. and trying to get ridiculously ripped by cutting down to 165 lbs, and my daily caloric requirements were 2000. What would it matter if I ate 720 calories worth of protien along with 1280 calories worth of table sugar vs. eating 720 calories worth of protien along with 1280 calories worth of brocolli vs. eating 720 calories worth of protien along with 1280 calories of fish oil vs. 720 calories worth of protein along with 1280 calories of a mixture of carbs and fats.....and so on?

Lots of answers possible here. Broccoli has fiber. The fish oil and sugar combos would leave you impacted. Literally, full of shit. High dose fish oil is known to thin blood. If you were cut, you may react like a bleeder. Table sugar, broccoli, and fish oil combos would leave you depleted of necessary vitamins. Some would argue of the efficacy of only taking a multivitamin. A variety of fats are needed for proper maintenance of hormone levels. The body can live without carbs, but protein and fat are a must. Without saturated fat, you would suffer dramatically upset testosterone levels. On and on and on.

I hope this is a little of what you wanted to know. I can and do cut while eating bread pudding after workouts. I just returned from a workout, and I did consume 500 calories of sugar. In fact it was way "worse" than table sugar. It was malto/dextrose. Some people worry about sugar causing inflammation. I have never ached after eating sugar, so it's irrelevant to me. I eat dates, kiwis, bananas, oranges etc. with breakfast. They are in many ways like table sugar with vitamins. I eat a sesame seed bun with lunch. It spikes insulin higher than table sugar.

My first five months of bulking I ate nothing but "healthy foods". No white bread, brown rice, oats, whole grain, cut out fruit except breakfast, no cheating. Now I eat mashed potatoes , sesame seed buns, fruit, and I had a couple ribs the other day. I am making great gains, and I am not gaining excessive fat. I am much happier, and getting my 4100 calories in is enjoyable. I just had a physical, including a fasted glucose, and the nurse laughed at how good all my markers were.

What I'm getting at is, moderation is the key. Too much heroin you overdose, too much water your brain swells, too many women you get dick rot.

Edit: It's my bedtime here. I'm about to eat a chicken breast and a bowl of rice.
2nd Edit: White rice!

[greemah]

If you need to hit 200g carbs in a day, you could get all that eating junkfood or oats and it wouldn't make a difference on body composition. Health wise though that's a different story..

[greemah]

IMO, you should not have carbs after 6-7pm, depending on when you go to sleep.

That's a myth mate - http://www.leangains.com/2011/06/is-...r-for-fat.html

[JSully]

That's a myth mate - http://www.leangains.com/2011/06/is-...r-for-fat.html

I'm pretty sure I said "in my experience".

If you think of your body as a machine that requires fuel, and that fuel is glucose which is essentially carbohydrates, then what is the point in supplying carbohydrates if you're going to be doing nothing but watching TV and sleeping for the next 8-10 hours? Seems like a waste of calories IMO. I would rather use all my carbs pre, during and post workout to fuel my training and recovery.

[Behemoth]

I'm pretty sure I said "in my experience".

If you think of your body as a machine that requires fuel, and that fuel is glucose which is essentially carbohydrates, then what is the point in supplying carbohydrates if you're going to be doing nothing but watching TV and sleeping for the next 8-10 hours? Seems like a waste of calories IMO. I would rather use all my carbs pre, during and post workout to fuel my training and recovery.

Your experience is flawed [in large part] due to your lackadaisical approach on dieting not allowing any of your drawn conclusions to be accurate due to lack of control in this anecdotal theory.

[Behemoth]

I'm pretty sure I said "in my experience".

If you think of your body as a machine that requires fuel, and that fuel is glucose which is essentially carbohydrates, then what is the point in supplying carbohydrates if you're going to be doing nothing but watching TV and sleeping for the next 8-10 hours? Seems like a waste of calories IMO. I would rather use all my carbs pre, during and post workout to fuel my training and recovery.

With respect to solely the calorie timing topic being addressed here do you not realize that if you eat a meal (regardless of content) almost certainly some of the energy contained therein is going to be stored? If your body burns less calories at a given interval each day as well as burns more calories at a different interval each day what difference does it make when you make your body derive energy from food and when you make it derive energy from stores?? If your body is in a proposed time of high metabolic activity and it's in a deficit of energy in the form of recently ingested calories it's going to derive it's energy from stored sources. And adversely if it's in a proposed time of low metabolic activity and it's in a surplus of energy in the form of recently ingested calories it's going to derive it's energy from recent surplus and yes, store some also.

Your body stores and releases lipids all day long. Thinking you can time your meals to defy thermodynamics is pretty illogical.

[Behemoth]

With regard to the original question at hand on macro and micro nutrient breakdown this is pretty much your answer...

If you need to hit 200g carbs in a day, you could get all that eating junkfood or oats and it wouldn't make a difference on body composition. Health wise though that's a different story..

[Behemoth]

With regard to the original question at hand on macro and micro nutrient breakdown this is pretty much your answer...

To expand somewhat on this in the context of one day if you meet your nutritional needs for the important stuff (IE hit as much protein as your body is going to use, get in enough good fat [though this one is not all that important for just the context of one day]) and then decide to fill in the extra 1000 calories (or whatever the number is) with oreos instead of oats and olive oil it's not going to make one fucking bit of a difference for that day.

However, keep up that trend over time and as greemah said there may be tangible discrepancies (mostly depending on how shitty and how long). Things like insulin and leptin sensitivity, blood pressure, cholesterol, hormones blah blah may start being altered.

The take home lesson is that since one day means nothing if you eat a pack of double stuff oreos (and probably not even 2 or 3 or 4 days) then a little deviation from the broccoli and grilled or boiled chicken breasts on a day to day basis really means nothing unless you have some already serious and pressing condition. I personally eat about 1/4 of my calories on a daily basis from casual food. The only time that gets cut on is on a strict diet but not because I'm under the impression that it has any major effect on my results, but simply due to satiety and adherence.

[Behemoth]

One more thing to address that mr wide deep alluded to here...

I disagree. The metabolic benefit alone makes at least 1.5g/lb. worth while. That's assuming your diets calories can accommodate it..

Which is completely valid. Different macro nutrients have different thermic effects. Where protein is by far the highest at an estimated 20-30% whereas carbs are around 5% and fats are somwhere around 1-2%.

[Invain]

Cliffs: Both macros and calories matter. The timing of macros also matters IMO.

One thing people tend to forget/don't realize is that your body adapts very fast to your diet. Hormone levels can differ based on certain foods eaten. Your metabolism is also constantly changing, though these changes can be negligibly small, nobody ever has the exact same maintenance calories every day.

[PhxdB]

Hm, Iron Addict had an article about the most popular types of diets and how their macros add up. Oldschool high carbs low fat vs modern low carb and etc... He talked about how your body responded to the macros during a cut.

I'll try and post it if I can but I can't find it. Interesting stuff. All I remember was he was all about low carb.

[JSully]

Your experience is flawed [in large part] due to your lackadaisical approach on dieting not allowing any of your drawn conclusions to be accurate due to lack of control in this anecdotal theory.

as flawed as it may be, I dropped 20 total lbs and added 7lbs of LBM in 8 months by following my inaccurate anecdotal theory. During said 8 months, I only was only in a calorie deficit for 4 of them and maintenance the other 4. My hip snatch went from 165 to 225. Hang clean from 295 to 335, front squat from 365 to 415, deadlift from 605 off the floor to 635 from a 2" deficit and every single one of my throws increased... while dropping 7% bf and adding 7lbs LBM. Please sir, tell me how MY experience is flawed.

With respect to solely the calorie timing topic being addressed here do you not realize that if you eat a meal (regardless of content) almost certainly some of the energy contained therein is going to be stored? If your body burns less calories at a given interval each day as well as burns more calories at a different interval each day what difference does it make when you make your body derive energy from food and when you make it derive energy from stores?? If your body is in a proposed time of high metabolic activity and it's in a deficit of energy in the form of recently ingested calories it's going to derive it's energy from stored sources. And adversely if it's in a proposed time of low metabolic activity and it's in a surplus of energy in the form of recently ingested calories it's going to derive it's energy from recent surplus and yes, store some also.

Your body stores and releases lipids all day long. Thinking you can time your meals to defy thermodynamics is pretty illogical.

Of course I know some of it will be stored, however injesting 150-200g dextrose/maltodextrin gives me energy. I can feel it 2 minutes after I drink it. If I only drink 100g, I can feel my energy fade after about 45 minutes of exertion. So then I either drink more, wait a couple mins and continue, or adjust my intake the following workout. I'm not quite sure how that is illogical. When I'm competing, I carry around a box of Nerds with me and eat them all day. I feel the energy boost from it, how would that NOT affect my performance? My point was if I'm only allowed to have 275g carbs per day, what is the purpose of dragging ass in the gym just do I can have them for dinner? I'd rather have the best workout I can while in a calorie deficit, rather than going catabolic during training because my preworkout nutrition was poor. On the flipside, I think it's illogical to think that nutrient timing has no affect on your body, moreso when you can simply listen to your body and feel the affects of food you've just eaten. Maybe a feeble minded person that doesn't care about losing strength while cutting would follow this proposed mindset. Hence the difference between bodybuilders and strength athletes. But then again, I'm pretty sure all the top level BBers eat specific things pre-during-post training. If there was no point to eating specific food at a specific time, why would they change their nutrition around to benefit their training?

So.. take my posts with a grain of salt because apparently, my nutrient timing is illogical and my experience is flawed.

lol

[BallsWideDeep]

I like to stack a lot of carbs around my workout time. Rice and oatmeal before, gatorade during, mass shake after. I feel it energizes me, but I never tried it any other way. It is just part of my ritual. It could be psychosomatic.

[Behemoth]

Of course I know some of it will be stored, however injesting 150-200g dextrose/maltodextrin gives me energy. I can feel it 2 minutes after I drink it. If I only drink 100g, I can feel my energy fade after about 45 minutes of exertion. So then I either drink more, wait a couple mins and continue, or adjust my intake the following workout. I'm not quite sure how that is illogical. When I'm competing, I carry around a box of Nerds with me and eat them all day. I feel the energy boost from it, how would that NOT affect my performance? My point was if I'm only allowed to have 275g carbs per day, what is the purpose of dragging ass in the gym just do I can have them for dinner? I'd rather have the best workout I can while in a calorie deficit, rather than going catabolic during training because my preworkout nutrition was poor. On the flipside, I think it's illogical to think that nutrient timing has no affect on your body, moreso when you can simply listen to your body and feel the affects of food you've just eaten. Maybe a feeble minded person that doesn't care about losing strength while cutting would follow this proposed mindset. Hence the difference between bodybuilders and strength athletes. But then again, I'm pretty sure all the top level BBers eat specific things pre-during-post training. If there was no point to eating specific food at a specific time, why would they change their nutrition around to benefit their training?

I'm not in disagreement with this. The point I was trying to drive home was that your filler from nerds and dextrose doesn't make you any fatter than oats.

Yes timing certainly matters with regard to a workout performance and recovery, but thinking that timing alters the net surplus or net deficit at the end of the day is not correct. That again is what I was trying to drive home.

To expand somewhat on this in the context of one day if you meet your nutritional needs for the important stuff (IE hit as much protein as your body is going to use, get in enough good fat [though this one is not all that important for just the context of one day]) and then decide to fill in the extra 1000 calories (or whatever the number is) with oreos instead of oats and olive oil it's not going to make one fucking bit of a difference for that day.

I wasn't saying here that drinking a days worth of calories from mcdonalds fryer oil was equivalent to steak and brown rice.

I'm saying if you get the same needed nutrition and the rest is "filler" calories it doesn't matter where they come from for the short term. That needed nutrition will be your protein, some good fats, and any nutrition that will impact your performance in the gym (or any other endeavor that could affect your results). If those points aren't compromised it's not going to make a difference in the scheme of a day or a few.

[JSully]

I'm not in disagreement with this. The point I was trying to drive home was that your filler from nerds and dextrose doesn't make you any fatter than oats.

Yes timing certainly matters with regard to a workout performance and recovery, but thinking that timing alters the net surplus or net deficit at the end of the day is not correct. That again is what I was trying to drive home.

This I agree with. Your prior post seemed more like an attack rather than a stance on a certain topic. My bad for the misinterpretation. I choose nerds/dextrose because it gets in the bloodstream fast, however oats/rice are just as fine; I just don't feel the energy they give me as immediate as I feel the energy from the nerds/dextrose. I'm not sure if you misread my post or if I just wasn't very clear. Timing your nutrients isn't going to change your requirements for the day, its only an aid in performance. As previously stated, my cutting calories are about 2700, and I set my macros 275/275/65 (p/c/f). I time my carbs for breakfast, lunch and the majority pre workout (about 1pmish) then no more carbs for the rest of the day. That makes up my 275g. When I go to maintenance, I'll have 500g+ and do the same thing, but allow 50-60g carbs with dinner. At the end of the day, it's total calories that matter. Timing macros around your highest expenditure parts of the day (while in a calorie deficit) helps with performance/recovery as well as avoiding the storage of those incoming calories, especially if they are simple carbs, which mine are. Hypothetically, if I've burned 75% of what I just took in during my training, that's all the less that has a possbility of getting stored and my body can get back to burning fat faster.

I agree that it doesn't matter what you eat, so long as you hit your goal protein, goal calories and everything else is just filler. Again, by experience, if you're going for performance, you're most likely going to want a good amount higher carbs than fats, but that varies person to person. That's why I eat cheeseburgers for dinner and candy throughout the day. Total calories are going to determine whether I'm gaining or losing weight. The macros are going to determien whether that weight is good or bad.

[Alex.V]

Your body stores and releases lipids all day long. Thinking you can time your meals to defy thermodynamics is pretty illogical.

THANK YOU!!!

Yes, this applies to ALL energy storage pathways.

[Behemoth]

It was not an attack on you, but simply the faulty theories being spouted, which were completely incorrect. The brunt of all my posts have not been discrediting the benefits of efficient nutrient timing, but rather discrediting that less efficient nutrient timing is not a factor for really any discernible difference in the energy equation as it was alluded to below. My stance on macro breakdown was stated in post #9 in that macros matter, but for the most part micros (or clean/dirty) really doesn't matter much in ones body composition.

You should be having some sort of protein with every meal. IMO, you should not have carbs after 6-7pm, depending on when you go to sleep. Carbs break down to sugar in the form of glucose. Glucose is used for fuel. Glucose causes an increase in insulin which drives protein and carbs do your muscle to be used for energy. If you aren't doing anything that is going to use that energy, it's going to get converted and stored as fat to be used later.

[brihead301]

Good discussion here, but I'm still not 100% clear on all this. So let me see if I've got some things straight here:

1.) It is, in fact, true that eating less calories then maintainance will cause you to lose weight, but could still change your body composition if protien is too low (your body uses energy from muscle, and stores fat)

2.) Protien is the most important macro in body composition. Therefore if one wants to cut, as long as they are getting adequate protein, and eating in a deficit, they will lose mostly fat and maintain most of the muscle mass (assuming the deficit isn't too low) no matter where the rest of the calories come from (fat or carbs).

3.) Carbs are a better energy source then fat, but tend to get stored as fat if not used in training. Therefore, assuming protien is kept constant, more carbs as the remainder of the calories are more geared towards performance rather then physique.

4.) Assuming protien is kept constant, more fat as the remainder of the calories are more geared towards physique.

5.) Basically, as long as one is in a deficit, and gets adequate protien each day....they will lose fat, and maintain muscle pretty much either way (carb dominant or fat dominant remainder of calories), assuming they are training properly and not in too much of a deficit, and hit their caloric goals each day.

6.) As far as composition goes, the type of carbs isn't really important (GI doesn't matter), neither is the type of fat (healthy vs. "bad" fats).

Thanks a lot!

[Behemoth]

Good discussion here, but I'm still not 100% clear on all this. So let me see if I've got some things straight here:

1.) It is, in fact, true that eating less calories then maintainance will cause you to lose weight, but could still change your body composition if protien is too low (your body uses energy from muscle, and stores fat)

Yes, fact that eating less calories than maintenance will cause you to lose weight. Could you still change body composition if your protein is too low? Well depends on where the calories are and how low the protein is. If you need 250g of protein per day and you're eating a maintenance and training hard but only getting in 150g of protein no you're not going to be losing muscle.

2.) Protien is the most important macro in body composition. Therefore if one wants to cut, as long as they are getting adequate protein, and eating in a deficit, they will lose mostly fat and maintain most of the muscle mass (assuming the deficit isn't too low) no matter where the rest of the calories come from (fat or carbs).

I'll go with protein being the most important but it is no way the be all end all. Carbs can be more anabolic and protein sparing than additional protein itself in instances.

3.) Carbs are a better energy source then fat, but tend to get stored as fat if not used in training. Therefore, assuming protien is kept constant, more carbs as the remainder of the calories are more geared towards performance rather then physique.
Yes, carbs a better sources of immediate energy than fat but are VERY SELDOM stored themselves as adipose tissue. Thinking of carbs as for performance but as a hindrance towards physique goals is plain inaccurate. I ask this quesiton all the time but I'll ask it again, how often do you see people bulking up and getting jacked on a ketogenic diet? I personally don't anybody (not saying it's impossible). Understand that nutrients that are important in building muscle are also important at preserving muscle. Carbs should in no way be considered detrimental for physique goals if you manage them correctly

4.) Assuming protien is kept constant, more fat as the remainder of the calories are more geared towards physique.

NO

5.) Basically, as long as one is in a deficit, and gets adequate protien each day....they will lose fat, and maintain muscle pretty much either way (carb dominant or fat dominant remainder of calories), assuming they are training properly and not in too much of a deficit, and hit their caloric goals each day.
Doubtful. Carbs in a deficit are going to preserve your muscle better than anything else after meeting your protein needs

6.) As far as composition goes, the type of carbs isn't really important (GI doesn't matter), neither is the type of fat (healthy vs. "bad" fats).
Pretty much, yes. Though over time the negative effects of crappy food can start to add up which can present problems.

Thanks a lot!

.....

[brihead301]

High protien....majority of carbs as the remainder of my total it is!

Thanks for the clarification.

[Invain]

There's no such thing as a "better" source of energy. Short and medium chain triglycerides can be absorbed and utilized just as fast as simple carbs. Obviously fat is the preferred long term source of energy storage in the body as it is more efficient. Don't forget the difference between aerobic and anaerobic respiration as well. If you were a marathon runner I would argue that fats may be a better source of energy. I read a paper a while ago about new research with long distance runners and Intramuscular triglycerides (IMTG), which are droplets of fat within skeletal muscle stored primarily for use during exercise, much like glucose is stored as glycogen.

I go against the thoughts of most when it comes to "necessary" carb intake. The insulin response from carbs is slightly overrated, as almost everything you eat elicits an insulin response. In my eyes carbs are necessary for one thing; keeping glycogen stores full. The main time your body HAS to use glucose specifically is during anaerobic exercise. Your body as a whole can operate primarily on fat/ketones just fine, with your brain being an exception.

[Majestic]

Explosive thread, I'm agreeing w/ Behemoth.

[Alex.V]

If you were a marathon runner I would argue that fats may be a better source of energy. I read a paper a while ago about new research with long distance runners and Intramuscular triglycerides (IMTG), which are droplets of fat within skeletal muscle stored primarily for use during exercise, much like glucose is stored as glycogen.

In my eyes carbs are necessary for one thing; keeping glycogen stores full. The main time your body HAS to use glucose specifically is during anaerobic exercise. Your body as a whole can operate primarily on fat/ketones just fine, with your brain being an exception.

You and I will have to disagree intensely here. Anaerobic "exercise"? That is very much NOT the only time anaerobic pathways are used. The effort required to get up out of your chair, pick up a bag, walk uphill or go up a single flight of stairs (or single step) can temporarily overwhelm the body's aerobic energy systems, which means glucose becomes a vital fuel.

Marathon runners and distance athletes still require tremendous amounts of glycogen in their systems- simply because fat is the primary energy source does not mean it is the only- glycogen is precious in long distance activity, it provides the energy needed for short bursts of speed, or sudden minor increases in workload (i.e., running up a slight gradient). Take this away, and these athletes will crash and burn.

Ask ANY serious athletes (whether they be olympic lifters, marathon runners, ironman triathletes, ultramarathoners, or shot putters) if they can operate at peak performance on ketones and fats, and they will likely look at you much in the way my dog looks at me when I take away her food bowl.

While theoretically much of your argument would seem logical, it's a bit heavy on the paleo kool-aid that's been going around.