The Female(?) Athlete Triad - Part III/III: Road to Recovery! Step #2 = Accept There is No Magic Macronutrient Ratio

No need to raid another tomb, Lara, the quest for the one and only ideal macronutrient composition that will yield optimal results for the rest of your life ends here (img courtesy of Paramount)!

I am not planning to bore you with a longish summary of the previous installment(s) of this series, here. Still, I don't want to head on to the 2nd step of the "Road to Recovery", which is going to deal with the quest for the "optimal" macronutrient ratio, without a brief reminder of the central role of nutrient availability in both the etiology, as well as the recovery from the athlete triad - or, as Dr. Zanker from the Carnegie Research Institute at the Leeds Metropolitan University in the United Kingdom puts it, the simple fact that the "exercise associated reproductive dysfunction in women is attributable to deficits of readily available energy" (Zanker. 2006)

In a couple of more general remarks some of you have recently (not without good reason, by the way) criticized my excessive and in parts random use of mark-ups like bold print or underlining. In the introductory paragraph to today's post the word "readily" is however so important that the underlining is obligatory.

Your hypothalamus does not like to wait, therefore "readily" is the keyword, here!

It is after all the lack of appropriate readily available energy, primarily in the form of circulating glucose, liver glycogen, and adipose tissue triacylglycerol that precedes the low plasma insulin concentration and reductions in total body fat content and corresponding disturbance of leptin secretion, ghrelin, cortisol, thyroid and of course luteinizing hormone (see data in figure 1; the absolute levels from the healthy group may also serve as a reference to compare your own labwork to; mind the units!).

Figure 1: Hormonal and glucose metabolism (* indicates 24h values) of women with functional hypothalamic amenorrhea (not necessarily exercise induced) expressed relative to values in eumenorrheic control; values above the bars indicate the total values of the respective markers in healthy controls and may provide you with some orientation, when you are looking at your own bloodwork (data based on Loughlin. 1998)

In order to avoid / counter the reproductive and associated problems and break out of the vicious circle of the athlete's triad, Zanker proposes the following three steps (based on Zanker. 2006; yet with a couple of additions from my side): 

• Avoid abrupt and rapid weight loss and maintain an “adequate” body fat content, which may be individually specific, but coincides with regular reproductive function.
• Consume adequate amounts of energy to fuel your increased metabolic demands; never go below your resting energy expenditure, regardless of whether you  want to or even have to lose weight.
• Make sure you get an adequate amount of carbohydrates either on a continuous (low GI carbs with every meal) or in a cyclic manner as part of a low(er)* carbohydrate diet with a baseline intake of 90-120g/day and additional carbs after every workout.
  *compared to the RDA of ~60% carbs

"Carbohydrates? But aren't those just making you fat?" With this very question that's now probably on the mind of one or two (or three ;-) of you, we did eventually arrive at the topic of this episode of the Athlete's Triad Series:

Is there a ideal macronutrient ratio that will prevent the onset
and help you get rid of the athlete's triad?

To be honest, I don't know the answer to this question... and although I had almost typed the word "yet" win the place where you now see the "..." , I must admit that I am not even sure if there actually is a definitive answer to this question. What I do have to offer, though, is a couple of things to keep in mind, when it comes to the macronutrient make-up of your diet.

1. There is no such thing as a "bad" nutrient. There are about as many good arguments to vilify the overconsumption of protein, as there are arguments against the usual scapegoats, carbohydrates and fats.
2. Glucose and saturated fats can be essential, too. Just because your body can produce carbs and saturated fats on its own, this does not mean that you do not have to, let alone should not eat them.
3. The optimal macronutrient ratio will change over time - just like and in response to the way your physique, conditioning, lifestyle, training and general stress levels  will be changing. This implies that diet X, which may have worked magically for you, when you got rid of slabs of body fat is now that you are finally in the "normal range", let alone already so lean that your body's alarm bells are constantly ringing, hampering your progress.

And even if the previous comments on the importance of readily available energy and glycogen repletion would suggest that carbohydrates should make up the lion's share of the diet of any athlete trying to recover from the triad (or not to fall victim to it), an extreme high carbohydrate alone is neither guaranteed to solve the problem nor is it a sustainable way of eating you could stick to once you've "carbed" yourself out of the dark hole you have been digging over the past months.

Readily available energy? Does that mean I have to eat sugar all day?

Figure 2: Cortisol (left) and testosterone (right) levels in healthy men after 10 days on high protein vs. high carbohydrate diets (based on Anderson. 1987). Tegelman et al. report similar results from Swedish elite male Ice Hockey players after a reduction of fat and an increase in carbs (Tegelman. 2007)

On the one hand, we've known for over two decades that a high carbohydrate diet based on bread, vegetables, fruit, juices, pastry, and candy having a protein / carb / fat ratio of 10% / 70% / 20% will result in lower cortisol and higher testosterone levels (in men) than a high protein diet with a protein / carb / fat ratio of 44% / 35% / 21% that's based on lots of meat, fish, poultry, egg whites, and a liquid dietary supplement protein supplement (Anderson. 1987; see figure 2). On the other hand, a closer analysis of the data I compiled based on the tabular overview of pertinent studies on amenorrheic from the review by Manore (see figure 3 in the last installment) suggests that real.world advantage of carbohydrates depends on the deepness of the whole you already dug (the deeper the more advantageous) and your willingness / ability to cover or even surpass your daily energy requirements (the more you eat on a daily basis and in at least three square meals spread equally across the day, the less you will depend on the readily available energy from carbs).

Against that background, the high carbohydrate intake (62% of total energy from carbohydrates; nutrient ratio in grams 16% protein, 71% carbs, 14% fats) was probably necessary for the women in the eumenorrheic group with an energy intake of slightly less than 30g/kg body weight (figure 3, R5).

Figure 3: Macronutrient compositions (in kcal!) of amenorrheic and eumenorrheic women from 15 different studies (based on an overview in Manore. 2002)

For the eumenorrheic female athletes who were at, or way above the average mean energy intake of 35g/kg body weight, the "high" carbohydrate intake of 265g/day probably wasn't detrimental. On the other hand, it appears questionable, whether an increase in protein intake from 1.2g protein per kg of body weight to 1.5-2.0g/kg and a corresponding protein to carbohydrate ratio of 25% / 62% would not have been more facilitative to their goals (specifically if those include strength training). The same goes for both, the replacement of yet another part of the carbohydrate ration with an isocaloric amount of fats and the overall role of fats in the etiology of and the recovery from the athlete's triad.

The fat-phobia still loomed large, when the majority of studies was conducted

Part of the problem of reconciling theoretical considerations, such as the "availability advantage" of carbohydrates and the scarce and almost exclusively observational data based on which I compiled the overview in figure 3 of this, as well as the last installment of this series, is that eating patterns of both the eumenorrheic, as well as the amennorheic athletes was geared towards the dietary paradigm of the day. With "the day" being the late 1980s and 1990s, i.e. those years in which the fat-phobia literally climaxed, it should be obvious that the baseline diet was low in fat and high in carbs.

Against that background it should also be clear that anyone trying to "cut calories" would reduce the amount of fats, the "bad energy dense heart killers" and keep the intake of carbohydrates constant (=high). This is probably also, the reason that the ostensible disproportionate lack of fats in the diets of the amenorrheic women vanished, once I weighted the data with the number of participants.

Figure 4: Total dietary intake of protein, carbohydrates and fats (in g; left) and differences between women with and without regular menses (right); data expressed either as simple group averages or weighed for the number of study participants (same sources as figure 3)

The picture that emerges after this adjustment has been done (figure 4, right, light bars) is clear and stands in line with my initial remarks on the primary of readily available energy in the form of circulating glucose, liver glycogen, and adipose tissue triacylglycerol, of which at least the former are way more readily derived from carbohydrates than fats.

And even the triacylglycers do, as the name implies, require a certain amount of glucose for the glycerol backbone (could be produced in the liver from amino acids and/or fats, though) and a minimal amount insulin to be stored in the fat cells (can be secreted in response to high amounts of protein and fat, as well, though).

So no fats? Just carbs and some protein?

Yet though carbohydrates have the availability bonus and proteins are necessary to maintain, better even build muscle mass, you would be ill-advised to steer clear of all dietary fats and, even more so the many good foods that contain them. Not so much because of the "essential" polyunsaturated fatty acid, though. According to a study by Tomten and Høstmark the dietary intake of PUFAs in 20 female runners with regular (n=10) and irregular (n=10) menses (LH levels of 7.6 vs. 2.9 IU/l!) was not statistically different. The intake saturated fats (-28%) and even more the intake of MUFAs (-38%), on the other hand was (Tomten. 2009) and the corresponding total fat-intake of 1.1g/kg body weight was obviously not sufficient to maintain optimal hormonal levels in the presence of a training volume of 7.5h per week.

What about vegetarianism? I know a few of you won't like this, but unless you are at least ovo-lacto vegetarian, i.e. a person who eats dairy and eggs, you are going to have a hard time fueling your athletic endeavors appropriately. After all, vegetarianism is associated with hormonal and menstrual abnormalities even in the non-athletic population, when they are dieting (Pirke. 1986). If you combine a mild energy deficit, as it is often seen in vegetarian, let alone vegan athletes, simply because it's harder for them to cover their energy and specifically protein and fat requirements without guzzling omega-6 oils and soy shakes all day (both not advisable, by the way), it is actually not surprising that Benson et al. mention vegetarianism right along low calorie intakes, nutritional inadequacies and low body fat stores as one of the main contributers to the (female) athlete triad (Benson. 1996).

Now you can certainly argue that all this comes down to the energy density and the correspondingly lower overall energy intake and could have been compensated for, if the women with menstrual irregularities had simply eaten more carbohydrates. In view of the fact that they didn't do so, I can hardly refute this argument. On the other hand, we have seen in the previous installment that an overexpression of GH and ghrelin is in as much part of the problem as too little insulin and a pathologically high insulin sensitivity. And some more fat in the diet (alongside carbs / not as the sole energy source!) couId in fact come handy to get that back in check.

Moreover, having a carb to fat ratio of ~2:1 (in energy equivalents) and a baseline fat intake in the range  of 80-100g (total) as the female runners with regular menses in the Tomton sudy had, has the beauty of never having to throw away the egg yolks, being able to get your share of fatty fish, full fat dairy, Kerrygold butter, virgin coconut and olive oil and beef or better calf liver as well as nuts once in a while. This in turn will allow you not just to stay sane and flexible with your diet, but also to satisfy your need for all those vital micronutrients you won't find in any of E-number laden fat-reduced garbage from the "low fat" shelves at the supermarket.

You see, in the end it all comes back eating simply more of the usual suspects, many people would probably file under "a paleo diet with lots of (safe) starches & fruit to fuel the energetic demands of a hard working athlete", these days.

If we think of the hypothetical daily energy requirement of 2000kcal/day which is often used as a reference for the nutrition information on those products of which you are going to buy less in the future (most real foods don't have nutritional information printed on them, you know ;-), the corresponding "numbers" could be anywhere on a continuum

• from 110g protein / 190g carbs / 100g fats, for someone without an endurance component in his workouts*, 
• to 100g protein / 240g carbs / 80g fats for someone who has a major endurance component and / or follows a high volume lifting routine*
  *pre- and post workout nutrition are not included, here!

This approach would ensure that you get enough protein, appropriate amounts of readily available energy, mainly in the form of safe starches and fruit, quasi unlimited amounts of vegetables and so much fat that you don't have to resort to the devastating "chicken breast, rice and broccoli diet", which will only worsen your situation.


References:

• Anderson KE, Rosner W, Khan MS, New MI, Pang SY, Wissel PS, Kappas A. Diet-hormone interactions: protein/carbohydrate ratio alters reciprocally the plasma levels of testosterone and cortisol and their respective binding globulins in man. Life Sci. 1987 May 4;40(18):1761-8.
• Benson JE, Engelbert-Fenton KA, Eisenman PA. Nutritional aspects of amenorrhea in the female athlete triad. Int J Sport Nutr. 1996 Jun;6(2):134-45.
• Laughlin GA, Dominguez CE, Yen SS. Nutritional and endocrine-metabolic aberrations in women with functional hypothalamic amenorrhea. J Clin Endocrinol Metab. 1998 Jan;83(1):25-32.
• Manore MM. Dietary recommendations and athletic menstrual dysfunction. Sports Med. 2002;32(14):887-901.
• Pirke KM, Schweiger U, Laessle R, Dickhaut B, Schweiger M, Waechtler M. Dieting influences the menstrual cycle: vegetarian versus nonvegetarian diet. Fertil Steril. 1986 Dec;46(6):1083-8.
• Tegelman R, Aberg T, Pousette A, Carlström K. Effects of a diet regimen on pituitary and steroid hormones in male ice hockey players. Int J Sports Med. 1992 Jul;13(5):424-30.
• Tomten SE, Høstmark AT. Serum vitamin E concentration and osmotic fragility in female long-distance runners. J Sports Sci. 2009 Jan 1;27(1):69-76.
• Zanker CL. Regulation of reproductive function in athletic women: an investigation of the roles of energy availability and body composition. Br J Sports Med. 2006 Jun;40(6):489-90; discussion 490.

The Glucose Repartitioning Effects of Exercise: Moderate Beats High Volume Training When It Comes to Shuttling Glucose Away From Fat and Right into the Muscle

"Are 2h of cardio each day still too little!?  It must be my thyroid! Yeah, that's it. It must be the thyroid!" Could be bro, but if it is probably self-inflicted hypothyrodism

In the context of my dissertations on the unwarranted vilification of insulin as a "fattening agent" (go back to "The "Pro-Insulinogenic" Effects of Non-Nutritive Sweeteners + Mechanisms & Consequences" if you have not read the article already), I presented data from a rodent study to make a point that insulin's fattening effects depend on two closely related and highly familiar factors.

One is the over-consumption of energy that is the norm, not the exception here in the Western Obesity Belt. In conjunction with the lack of glucose depleting exercise this "ensures" that the intra-muscular and hepatic liver stores of the average Westerner are always topped off and the only change to get rid of the glucose that's floating the system of the coke-guzzling convenient generation on a day-to-day basis is to pack it away in the adipose organ.

That being said, it is only logical to assume that working out would help mitigate the problem by restoring the "normal" state of partly if not fully depleted glycogen stores and allowing insulin to do its original "glycogen anabolic". It is this process of insulin induced glucose partitioning towards the emptied glycogen stores of the skeletal musculature and the influence of (a) sedentarism (control), (b) aerobic exercise worth 300kcal/day, and (c) aerobic exercise worth 600kcal/day a group of scientists from the University of Kopenhagen in Denmark (Reichenkendler. 2013) investigated in their most recent study.

300kcal or 600kcal does it even make a difference?

For the experiment on which this paper that is supposed to be published in one of the upcoming issues of the American Journal of Physiology, Endocrinology and Metabolism, the researchers recruited 27 moderately overweight men (BMI: 28.1(1.8); age: 30(6) years; no diabetic relatives, weight stable for the last 6+months), randomized them to one of the three previously mentioned conditions.

According to which group the subjects had been randomized to, the participants either continued their sedentary lifestyle (CON) or performed daily aerobic exercise of 300 kcal/day (MOD) or 600 kcal/day (HIGH) for 11 weeks. The workouts were performed

• at a higher intensity (>70% of VO2max), three times per week, and
• at a low-medium intensity on the other three workout day

As you can see this is more of a chronic "general activity" + exercise study, than your average acute (let's save some money) trials and thus highly relevant to the aim of investigating the effect of chronic

"[...] moderate or high dose aerobic physical exercise on insulin-stimulated glucose uptake in individual femoral muscle groups, intra- and retroperitoneal VAT, abdominal (both anterior and posterior) and femoral SAT [subcutaneous adipose tissue] in sedentary, young and moderately overweight men." (Reichenkendler. 2013)

Moreover, the use of DEXA scan and non-invasive FDG PET/CT + hyperinsulinemic, isoglycemic clamp tests by the means of which the researchers assessed the body composition and glucose uptake of the study participants before and after the 11-week intervention ensured that Reichenkendler et al. would get accurate results.

Figure 1: Change in skeletal muscle (left) and body fat (right) glucose uptake from pre- to post-interverion (Reichenkendler. 2013)

Speaking of results, in view of the fact that the participants had not been been engaged in  in regular exercise, before the study was conducted and considering the fact that their maximal oxygen consumption [VO2max] of ≤45 ml O2/kg body mass/min mirrors their sedentary lifestyles, it is actually not really surprising that the unaccustomed exercise led to decreases in abdominal subcutaneous, visceral and leg fat masses in the two intervention groups - what may be surprising, though is the fact that those were not statistically different in the medium vs. high volume group.

On the other hand, only the high, yet not the moderate volume exercise (600kcal/day) led to significant increases in fat free mass in the legs (with the difference between the moderate and high volume achieving borderline significance; p = 0.06).

1:0 for 600kcal/day and high volume training!?

The additional muscle building benefit from the high(er) volume in the study at hand appears to conflict the results of a previous study by Rosenkilde et al. On the other hand, the most important message still remains: Working out twice as much is not going to double your fat loss! If anything it will make you feel miserable. Remember that and spread the word!

The muscle building advantage of the high volume endurance exercise is interesting. After all it appears to contradict data from a previous study by Rosenkilde et al. who observed detrimental effects of doubling the exercise volume from 300kcal/day to 600kcal per day in their study from August 2012 (read more).
If we scrutinize the different protocols, this could be a result of an ostensibly small, but physiologically relevant difference in the exercise prescriptions:

While the subjects in the study at hand had the four low intensity days to recover, the Rosenkilde study did not deliberately implement intensity differences like that - the subjects were just told "you burn 600kcal/day - no matter what!" In view of the still prevalent notion that this would be most beneficial if you achieved it by "training in the zone" (the non-existent "fat burning zone"), it is not unlikely that for Rosenkilde's subjects every day ended up a "high" intensity day and the constant exercise induced stress ended up backfiring.

If we go by the body composition data this this was not necessarily the case in the study at hand.The increase in fatloss every noob believes would come out of simply doubling your cardio workouts was not present either and that despite the fact that the exercise induced total body glucose disposal rate was increased  only in the high volume group (p = 0.03). In the moderate intensity group this effect did nor reach statistical significance.

Figure 2: The overall greater GLUT-4 response to insulin (signifying improvements in insulin sensitivity) probably explains the advantage of the medium volume training (Reichenkendler. 2013)

Much contrary to the total body glucose intake, where both the liver and the adipose tissue are greatfully sucking up the glucose your muscles are not snatching from under their nose, the total skeletal muscle glucose uptake rate increased in both, the moderate (p = 0.007) and high (p = 0.002) volume groups.

And now for the real surprises...

Did you know that high intensity, muscle damaging workouts reduce the post-exercise glycogen repletion rate and could thus impair the general glucose repartioning effects of exercise? It cannot be said for sure whether an increase in muscle damage was partly to blame for the lower glucose repartitioning effects in the medium vs. high volume groups in the study at hand, but the long-lasting (10 days) defect in glycogen resynthesis Kevin P. O'Really et al. observed in their 1987 study in response to 45min of eccentric cycling should remind you that "go heavy of go home" does not imply that you go home only, when your muscles hurt so much that even going light is not possible any longer.

Much contrary to what you may expect, though, the increase in muscle specific glucose uptake was more pronounced in the moderate (difference to control p = 0.02) than in the high volume group, where only a trend (p = 0.06) was observed.

And while the total glucose uptake rate of femoral adipose tissue did not change significantly in either of the intervention groups, the amount of glucose that ended up in the abdominal subcutaneous fat stores decreased. Just like the muscle specific glucose repartitioning, this effect did yet occur only in the moderate, yet not in the high volume groups.

Similarly the glucose repartitioning away the visceral adipose tissue of the midsection was statistically significantly only for the moderate volume group. For the subjects in the high volume group, the researchers observed a non-significant tendency (p = 0.09) for a decrease in the amount of glucose that was taken up by the visceral fat depots in the abdominal region.

---

What do we make of these counter-intuitive results: First of all, I would like to emphasize that any form of exercise is going to have a measurable repartitioning effect and whether the latter is "statistically significant" or not may in the end be of secondary importance. Moreover, the overall greater energy expenditure in the high volume regimen resulted in greater improvements in body composition than its low volume counterpart - irrespective of its "non-significant" or "borderline significant" glucose repartitioning effects (so much about "calories don't count", and "it's all about insulin and the fattening carbohydrates" ;-)

These abs were not sculpted by 600kcal/day workouts check out some more promising routines

On the other hand, the results of the study at hand to eventually confirm what the previously cited study by Rosenkilde et al. (click on the image with the mouse) already suggested: Doing more is not necessarily beneficial. Even in the presence of what you may call "light intensity recovery days", the daily hour (on the light days you will need way more than an hour to burn 600kcal) of the ever same, non-challenging exercise is not going to cut it - in the literal sense; or, to put it differently: doing low intensity training just to burn calories everyday is not yield the fat burning, muscle building or maintaining results you are looking for.

If you are looking for better alternatives, check out the fatloss support workouts in the Step By Step Guide to Your Own Workout.

References:

• O'Reilly KP, Warhol MJ, Fielding RA, Frontera WR, Meredith CN, Evans WJ. Eccentric exercise-induced muscle damage impairs muscle glycogen repletion. J Appl Physiol. 1987 Jul;63(1):252-6.
• Reichkendler MH, Auerbach P, Rosenkilde M, Christensen AN, Holm S, Petersen MB, Lagerberg A, Larsson HB, Rostrup E, Mosbech TH, Sjödin A, Kjaer A, Ploug T, Hoejgaard L, Stallknecht BM. Exercise training favors increased insulin-stimulated glucose uptake in skeletal muscle in contrast to adipose tissue: A randomized study using FDG PET imaging. Am J Physiol Endocrinol Metab. 2013 Jun 25. [Epub ahead of print]
   

Women Have a Much Harder Time Losing Body Fat Than Men, But Both Benefit From Doubling Their Protein Intake!

Image 1: Looks good, tastes good, is good - and contrary to zinc, ingesting 2x the RDA will help you lose body fat, instead of setting you up for insulin resistance.

Enough of useless (ALA, zinc) and useful (glutamin) supplements for at least 24h! Let's get back to what really counts: Training? No, not today,.. the other thing! The one, which is actually to be supplemented - your diet! Believe it or not - even after all those years, I am finding time and again that the food you put into your mouth has much more pronounced effects on the ways you look feel and perform than any of the countless useless and useful supplements. Accordingly and in response to the futile notion of "calories in vs. calories out" and the bomb-calorimeter representation of the human metabolism as a simple furnace, the past couple of years have seen an increasing public and (as of late) scientific interest in the effects varying macronutrient compositions will have on your ability to shed weight and, more importantly, to keep it off in the long run.

Submitted on December 30, 2011 and published in the latest issue of the Journal of Nutrition & Metabolism (9:55) the results of a "randomized clinical weight loss trial" comparing more or less isocaloric (-500kcal/day) weight loss regimen in 130 (58 male, 72 female) overweight middle-aged (40-56) subjects (BMI  =  32.5  ±  0.5 kg/m²) provide further insights into the real-world effects of  prescribed minimal protein intake levels on the outcomes of a 4 months weight loss and 8 months weight maintenance intervention (Evans. 2012).

RDA = 0.8g/bw vs. 2x RDA = 1.6g/bw protein - Round 1: Education & Adherence

In many of the previous posts on this issue (e.g. "High Carb vs. High Fat for Obese Type II Diabetics and What Really Happens, When Science Meets Real Life"), adherence or even an appropriate awareness of what "high protein" actually means turned out to be one of the main culprits as far as the significance of respective data is concerned (Krebs. 2012). In this respect, the subjects in the study by Evans et al. who were supported by a pretty extensive educational and support program that included

• the provision of electronic food scales and instruction on how to weigh and record food servings at all meals (logs were monitored for compliance on a weekly base!)
• a specific diet program with detailed instructions from a research dietitian including the menus, food substitutions and portion sizes
• an obligatory weekly 1 h meeting at the weight management research facility, where they received dietary counseling, had the ability to pose questions and instructions referring to the minimum of 30 min of walking 5 d/wk

constitute a positive exception from the average "study participant" who receives a handout with instructions and a clammy handshake for his/her willingness to step on the scale twice within a given time-frame.

Figure 1: Energy intake (total) from different macronutrients (left) and relative reduction compared to basesline in the 4-month weight loss and the subsequent 12 months "maintenance" period (based on Evans. 2012)

Based on the activity logs, the average amount of exercise was less than 100min/wk and not different between the two treatment groups. As far as the drop outs are concerned, there was yet a trend for lower drop out rates of the male participants in the protein compared to the carbohydrate group (9/28 vs. 18/30). 

Figure 2: Adherence to the prescribed macronutrient ratios was similarly "good" for men and women in both the high carbohydrate and high protein arm of the study (based on Evans. 2012)

The overall adherence to the prescribed nutrient ratios, i.e. 15% protein, 55% carbohydrates and 30% fat in the high carbohydrate and 30% protein, 40% carbohydrates and 30% fat in the high protein group was similarly good (the deviations were smaller than one standard deviation) among both men and women; and still, the net results of the study appear somewhat disappointing - at least if you make the all too common mistake of judging the outcome of an already intrinsically mislabeled "weight loss" intervention solely by the figures on your scale, which were, for the subjects in the study at hand, identical for both groups (PRO:-10.7  ±  6.8 %, CARB:-10.1  ±  6.2 %, expressed relative to body weight at baseline).

Feminists beware! Life is not fair...

A closer analysis of the data does yet reveal that despite an overall greater reduction in calorie intake in the high protein group (-31% vs. -22% in the weight loss phase and -27% vs. -16% in the maintenance phase) and slightly but statistically non-significantly greater body fat loss in the male participants on the high carbohydrate diet at the end of the maintenance phase, the "net" effect on the lean to fat mass ratio in men and women speaks in favor of increased protein intakes during phases of reduced energy intake.

Figure 1: It is obvious that compared to baseline the loss in body fat (expressed relative to baseline, left) was significantly more pronounced in the male compared to the female participants; the favorable effects of the high(er) protein diet on the lean to fat mass ratio (4% and 6% greater improvements) is yet of even greater importance for the ladies.

There is yet no denying that middle-aged women are - irrespective of their diets - having a substantially harder time losing body fat than men of the same age. In view of the fact that this is at least partly mediated by their significantly lower lean body mass to fat mass ratio (1.3 in women vs. 2.2 in men), the aforementioned protein sparing effects of "high" protein diets are of even greater importance for female dieters than for their male peers (cf. figure 3, right) - unfortunately, even the latter rarely rarely spare a thought about that, when their short-sighted and often likewise overweight Dr. tells them "you got to lose weight, if you want to see your grand children graduate, buddy!"

... and if you want sexual equality you got to lift weight and eat your meat ;-)

Against that background the results of the recently published exercise-only trial by Washburn et al. come to mind (cf. "Strength Training Ain't For Women -  Really!?" and Washburn. 2012). In the study at hand, The absence of at least a minimalist strength training regimen, as it was employed in the Washburn study, could in fact be one of the major reasons for the small overall effect size Evans et al. observed in their "walk in the park if you will" study. Eventually, the preservation of an already low amount of lean tissue mass is one thing, increasing the latter and thusly building the metabolic advantage of greater lean muscle mass, based on which the male study participants shed roughly 15% more body fat within the 12 month than their female peers is yet another one, of which I can hardly repeat often enough that it will not turn Angels into Divas over night (see image 2). And while you can easily regain 2 pounds of fat you lost, you will have to acknowledge that the lean mass you have either never built or lost over years of mainstream dieting, won't come back easily (cf. Beavers. 2011).

Image 2 (unkown Facebook source): Strength training and a high protein diet don't turn Angel's into Divas over night - what a pity ;-)

Bottom line: Regardless of whether you are a woman or a man, an angel or a diva, Homer Simpson, Peter Griffin, or Stanley Smith (cf. "Stocktaking, Goal Setting, -Tracking & -Resetting to Achieve a Healthy Weight & Shed Excess Body Fat"), greasy steaks, eggs, fish, dairy and a gym membership will not just have a much more pronounced impact on the outcome of your next diet, than all the diet products and books your money can buy, as an elementary part of your new lifestyle they will also lay the foundation of your future health - and what's even better: You will have more than enough extra years to spend all the money you would otherwise have spent on all those gimmicks, false promises, useless supplements and defacing cosmetic surgeries! Now you tell me eating a high(er) protein diet and spending time in the gym instead of the office was uneconomical ;-)

References:

1. Beavers KM, Lyles MF, Davis CC, Wang X, Beavers DP, Nicklas BJ. Is lost lean mass from intentional weight loss recovered during weight regain in postmenopausal women? Am J Clin Nutr. 2011 Sep;94(3):767-74. Epub 2011 Jul 27.
2. Evans EM, Mojtahedi MC, Thorpe MP, Valentine RJ, Kris-Etherton PM, Layman DK. Effects of protein intake and gender on body composition changes: a randomized clinical weight loss trial. Nutr Metab (Lond). 2012 Jun 12;9(1):55.
3. Krebs JD, Elley CR, Parry-Strong A, Lunt H, Drury PL, Bell DA, Robinson E, Moyes SA, Mann JI. The Diabetes Excess Weight Loss (DEWL) Trial: a randomised controlled trial of high-protein versus high-carbohydrate diets over 2 years in type 2 diabetes. Diabetologia. 2012 Apr;55(4):905-14. 
4. Washburn RA, Kirk EP, Smith BK, Honas JJ, Lecheminant JD, Bailey BW, Donnelly JE. One set resistance training: effect on body composition in overweight young adults. J Sports Med Phys Fitness. 2012 Jun;52(3):273.

A Bomb Calorimeter You Are Not! And That's Why Even the "Adjusted" Energy Values on Food Labels Are 5% Off

How productive are you?

A couple of you will probably remember the SuppVersity news from ~1 year ago in which I discussed the revelation that nuts (pistachios and almonds) effectively deliver much less energy (-25%) than the "label" or databases on the Internet will tell you. In other words, while these healthy snacks are still extremely calorie dense, our bodies are not exactly as well equipped as a bomb calorimeter to use that energy.... "bomb calorimeter"? That reminds me of a study I read about a week ago and remembered, today, when I was thinking about writing an article on a topic that is not the 10214124x study on how aerobic exercise is good for elderly obese diabetics, or how extract XYZ from whatever TCM medicine ameliorates the weight gain in obese rodents.

The study, I was thinking of was conducted at the Department of Nutrition and Dietetics, VU University Medical Centre in Amsterdam (Wierdsma. 2013) and with it investigating the practically highly relevant ability of our tummy to extract and digest (=make bioavailable) the energy from the foods, we eat, it is truely one of a kind. After all, corresponding ...

"[...] reference values for energy and macronutrient absorption are scarce, especially for adults in an outpatient ambulatory setting, which forms the usual circumstances for dietetic and nutritional interventions or therapy." (Wierdsma. 2013)

That may seem hilarious in view of the bazillions of money we are spending year by year to figure out "why we are fat", but believe it or not, due to the lack of data we (=science) simply estimate the ‘standard’ energy absorption to be at a level of 95%.

"We use 95% of the energy we eat" - says who?

What's the significance of the data? It goes without saying that measuring the energy that is not absorbed is only one of the things that will eventually be necessary to elucidate "how much calories the average dietary carbohydrate-, fat- and protein calorie effectively delivers. This information would yet still have been something we'd have to have before the dozens of studies on the thermic and other metabolically relevant effects of foods had been conducted. Why? Well, at least in those cases (a non-negligible part of the currently available research), where this effect was estimated by simply monitoring the weight gain of the subject over longer time periods, the result critically depends on the amount of energy from carbs, fats and protein that did even make it into the participants organism. If the latter is not 95%, but only 90% and differs from macronutrient to macronutrient, all previous results would be skewed.

This assumption is based on a single study from the 1970s, in which the amount of non-absorbed healthy adults is reported to be approximately 5% when digesting a standard diet (Southgate. 1970). A study like the one at hand, which was designed to

"[...] assess faecal energy, subdivided in its major contributors of fat, protein and carbohydrate losses, to quantify standard intestinal absorption capacity in healthy adults on a Western European diet in an ambulatory setting in The Netherlands by using a feasible and unique methodology of intestinal absorptiometry reflecting routine practice." (Wierdsma. 2013)

Put differently, the scientists wanted to find out (a) whether a calorie is a calorie or maybe just half a calorie and (b) whether this relation is different for the three main macronutrients, carbohydrates, fat and protein. What? Yeah, you'd think we'd know that all along, but aside from certain experts who know exactly "why we are fat", we obviously don't.

So what did the scientists do?

The Dutch researchers recruited 25 healthy subjects who had been deliberately picked from the staff of institutional healthcare workers at the facilities the authors are working at all had specific dietetic and healthcare knowledge and were thus skilled in adequately registering nutrient intake and meticulously collecting stools. Yep, you read me right: Over the course of 4 subsequent days, the study participants did not just have to track everything they ate and drink, they also had to collect specimen from what left their bodies "undigested" (=stool samples ;-).

"All faeces were collected during 72 h (day 2–4), as per the protocol, in specifically designed 5-L buckets. Faeces were weighed (faecal wet weight in g/day ), homogenised and immediately stored at <4°C until analysis. To measure faecal macronutrient content and to calculate intestinal absorption capacity of the healthy subjects, the faeces were analysed for energy, fat and nitrogen content." (Wierdsma. 2013)

Based on the nutrition data and the stool samples, which had been recorded and collected by all, but two male lazi-a**es who failed to comply to the rigorous requirements of the study protocol the scientists determined the intestinal absorption capacity and the faecal production and composition of male and female subjects separately:

Figure 1: Relative energy and nutrient absorption in male and female subjects (Wierdsma. 2013)

As you can see in my plot of the data in figure 1, the mean (SD) intestinal absorption capacity (as a percentage of nutritional intake) was different for fats, proteins and carbohydrates, so that the average subject digested only

• 89.4% (3.8%) of the total energy their meals provided,
• 92.5% (3.7%) of the "fat calories",
• 86.9% (6.4%) of the energy from protein and
• 87.3% (6.6%) of the calories from the carbohydrates

in their meals (the values in the brackets denote the corresponding standard deviations). Accordingly, fats are not only the most energetically dense macronutrient, they are also the one healthy individuals digest best an with the lowest inter-personal differences. Overall, ...

"[w]omen had a statistically significantly lower energy absorption capacity compared to men (88.0% versus 91.8%, respectively, P=0.02). A similar trend was seen for fat and carbohydrate absorption, although this was not statistically significant (P=0.19 and 0.06, respectively)" (Wierdsma. 2013)

The latter may be surprising, after all, it's usually the women who complain they'd only have to 'look at a piece of cake to gain weightÄ and how unfair it was that men 'can eat whatever they want and still stay relatively lean' (obviously, the latter is not only a function of how much you eat, but also of how much energy you expend and the symbolic piece of cake may well satify 50% of a woman's, but only 25-30% of a man's daily energy requirements).

What goes in must go out again ;-)

Figure 2: Daily faecal production (g/day; x-axis) negatively correlated with intestinal energy absorption capacity (% of the energy intake; y-axis) (n = 23) (Pearson’s r = 0.46, P < 0.05 for the total group, r = 0.65, P < 0.05 for women and r = 0.71, P = 0.05 for men; Wierdsma. 2013).

The mean daily stool production for both sexes was 141 (49) g (29% dry weight) and amounted to an energy loss of 891 (276) kJ, while the individual contribution of  fats, protein and carbohydrates was 5.2 (2.2) g, 10.0 (3.8) g and 29.7 (11.7) g, respectively. Accordingly, the average nutrient contribution to faecal energy content was

• 23% (10%) for fat,
• 20% (8%) for proteins and 
• 57% (23%) for carbohydrates.

With the stools of the female study participants containing a lower percentage of water than those of men (P<0.05), the energy content per gram of wet faeces was higher in women than in men (P<0.05), while the daily faecal nutrient losses were not statistically significantly different between men and women. Moreover, the scientists observed that ...

"[...]"the daily faecal production was positively correlated with faecal energy loss in kcal (Pearson’s r =0.80, P<0.001) [and negatively] correlated with intestinal energy absorption capacity (%) (Pearson’s r = 0.46, P<0.05)." (Wierdsma. 2013)

- an observation that means nothing else, but "the more you eat, the more inclined your body will be to have some energy pass through undigested"... or, in other words: Once you starve yourself, your body will try it's best use each joule of energy it can get! 

---

Bottom line: With the main results of the study at hand being that the average calculated standard for energy absorption in healthy Dutch adults is 90% and thus 5% less than it was previously assumed, it should be obvious that the already skewed "energy in vs. energy out" calculations you may have been conducting (against my explicit recommendation!) based on food labels and co are even less reliable than previously assumed.

"Accept There is No Magic Macronutrient Ratio" (read more)

On the other hand, the 5% more or less energy won't make a difference anyway, after all a main characteristic of our bodies is that they are no overtly simplistic bomb calorimeters, and their energy demands, as well as uptake depend on the total amount and composition (macronutrients, vitamins, minerals and other co-factors) of what we eat. If you want to gain or lose weight you will therefore not be able to forebear doing a 2-week food-log. Record all the foods and energy containing drinks you consume, sit down and (a) re-evalute the food quality, (b) take stock of the macronutrient ratios and (c) add / subtract foods, not calories or "energy" to establish a 20% caloric defict or 10% caloric surplus as a starting point for your diet / bulk. It's easy, it's bullet proof, but it's less convenient than relying on unreliable formula and databases.

References:

• Southgate DA, Durnin JV. Calorie conversion factors. An experimental reassessment of the factors used in the calculation of the energy value of human diets. Br. J. Nutr. 1970; 24:517–535.
• Van de Kamer JH, Ten Bokkel Huinink H,. Weyers HA. Rapid method for determination of fat in feces. J. Biol. Chem. 1949; 177: 347–355.
• Wierdsma NJ, Peters JH, van Bokhorst-de van der Schueren MA, Mulder CJ, Metgod I, van Bodegraven AA. Bomb calorimetry, the gold standard for assessment of intestinal absorption capacity: normative values in healthy ambulant adults. J Hum Nutr Diet. 2013 May 6.

Effects of Macronutrient Composition on Metabolic Signaling: Higher Protein Diet Favors Glycogen Storage in Muscle Over Adipose Tissue

Those of you who have already listened to the latest, revamped (and improved) episode of Dr Scott Connelly's BodyRx Show will already have heard of Suzanne Devkota's and Donald K Layman's study (Devkota. 2011) on the effects of different meal compositions on the postprandial glucose disposal. For the rest of you who have missed the episode and those of you who like their info white-on-black, here are the main results...

For 10 days, Devkota and Layman fed 60 rats a diet containing either 60% of energy from carbohydrates, 12% protein, 28% fat (CHO) or 35% carbohydrate, 35% protein, 30% fat (PRO) and evaluated plasma levels of insulin, glucose and C-peptide, as well as muscle and adipose tissue Akt, p70S6K and Erk 1/2 (markers of glucose and protein metabolism and cellular growth, respectively).

The graphs in figure 1 illustrate their most significant finding quite nicely. Other than in the case of the protein-fed rats, blood glucose is preferentially stored in fat tissue in the 30-90 min time window upon the ingestion of a meal in the high carb (CHO) group

Figure 1: Muscle and adipose tissue Akt expression (marker of glucose metabolism) after "high" protein (PRO) and high carbohydrate (CHO) meal, respectively (Devkota. 2011

The authors summarize this effect of macronutrient partitioning on metabolic signaling that is supported by the rest of their data as follows:

Animals chronically consuming the CHO diet produced greater metabolic signaling in adipose tissue to handle excess glucose and blunted signaling in skeletal muscle consistent with interpretation of insulin resistance. Conversely, animals consuming the PRO diet produced greater metabolic signaling in skeletal muscle with little signaling in adipose.

To fuel your workouts, it thus seems not only unnecessary, but even detrimental, to consume high amounts of carbohydrates. A "lower"  [note: even the high protein diet that was matched to the USDA's acceptable macronutrient distribution ranges (AMDR) had a carbohydrate content of 35% and thus a 1:1 protein to carb ratio!] carbohydrate intake, on the other hand, appears to prime your body to store glycogen primarily in muscle tissue. On a "high" protein, "lower" carb diet, you thus get the performance benefit without the unwanted fat gain and isn't this what we all are looking for?