Wednesday, December 19, 2012

Fat Loss Principles That Work: 10g+ of EAAs W/ Every Meal. Do Energetic Costs of Protein Synthesis Trigger This Effect?

EAAs beyond whey: It may not necessarily look like this, but this salad (repicecorner) is an EAA power horse with cheddar cheese (25% protein, 0.49 EAA / P ratio), tuna (in oil, 29%,  0.45) and kidney beans (9%, 0.45). You see, it does not always have to be chicken breasts or whey to get beyond the 10g+ EAA threshold, I have repeatedly suggested as one of the fundamental rules of dieting for weight loss, maintenance and muscle gain.
Many people take it for granted that you become fat, when you get old. If you look at the statistics, you could even make a point that obesity has some protective effects with esp. with respect to CVD mortality. Scientists call this the "obesity paradox" (Kastorini. 2012). What's particularly paradox, at least in my humble opinion, is yet not the phenomenon itself, but rather the fact that it gets smart scientists derailed from working on useful dietary and exercise interventions to prevent the development of heart disease, cancer, metabolic syndrome etc. in early years. Instead, they argue ex-post, i.e. when the baby has already been thrown out with the bathtub by comparing sick lean (in parts even cachectic) and sick "obese" people, why their statistical shenanigan that's based on the useless BMI produces paradoxical results. And that, when studies such as the one Jacobs et al. did in 2010 clearly show that 50+ year old men and women with waist circumference >120cm and >110cm, respectively, have 2x higher all-cause mortality risk than their lean peers - irrespective of BMI (Jacobs. 2010)!

To get lean and stay lean, yet not thin and skinny fat is therefore a challenge everyone...

... from the child in the Kindergarten to the obese granny in the nursing home is facing. Against that background a previous study by Loenneke et al. comes to mind. The results of their analysis, which were published in Nutrition and Metabolism in January 2012 clearly show that the amount of times people eat meals with a 10g+ EAA content per day was inversely related to percent central abdominal fat (Loenneke. 2012). In previous studies EAAs have also been shown to improve glucose clearance without increases in insulin and in the absence of effects on the fat burnin and health promoting expresion of AMPK-alpha2 in skeletal muscle tissue (see "EAAs Stimulate Muscle Glucose Uptake by Exponentiating Insulin's Effect on GLUT4 Expression"). With the advanced publication of a study by Coker, Miller, Schutzler, Deutz and Wolfe in the online verison of the Nutrition Journal a couple of days ago, the notion that EAAs have a particularly beneficial effect on fat loss - in this case in obese elderly individuals - gets further support from a well-controlled randomized trial (Cooker. 2012).

EAA-rich protein increases fat loss to a greater extent than low EAA protein

The researchers from the Center for Translational Research in Aging and Longevity and the University of Arkansas for Medical Sciences in Little Rock, AR, USA randomized 12 elderly individuals (mean age 69 years) to an 8 week, caloric restriction diet utilizing equivalent caloric meal replacements (~850 kcal/day; the exact nutrient composition can be found in figure 1) + ~400kcal from solid foods (total intake: ~1,250kcal/day; the subjects were free to chose their solid meals but were provided with a list of examples the should pick from, if possible).
Figure 1: Macronutrient composition of the meal replacements used in the study (Cooker. 2012)
The diet was designed to induce a 7% weight loss in two months. And while both,  the rate of weight loss (~1.6lbs per week), as well as the relatively high caloric deficit are certainly appropriate for someone with a 30+ BMI and ~40% body fat, leaner people will fare better with a less pronounced kcal deficit or (alternatively) have to add some strategically planned refeeds to the equation in order to minimize the loss of lean mass and, more importantly, avoid the ensuing reduction in energy expenditure (for the obese, the latter is actually less of the problem, because the downsides of being calorically deprived are at least partly counglucose tolerance and leptin sensitivity with every gram of body can actually help the body recognize that there is still plenty of energy that has just not been available (glucose) or "visible" (fat) before).
Figure 2: Changes in lean and fat mass (kg, left) and fractional protein synthesis rates (FSR) in participants receiving iso-caloric meal replacements with identical macronutrient compositions (see figure 1), but different amounts of essential amino acids (EAAs) content (Coker. 2012)
As the data in figure 2 goes to show you even the obese individuals in the study at hand lost a non-negligible amount of lean mass - unfortunately the body composition was measure with a sophisticated, but still body impedance based device, the trends are still accurate, but it is questionable in how much we are actually talking about ~2 and 2.5kg of muscle mass (figure 2, left), because somebody's "lean body mass" does obviously include more than just skeletal muscle.

When it comes to supplements, we are often like children on Christmas eve. About all the new stuff we get we tend to forget our former favorite and often way more fun to play with toys. Don't make this mistake and ditch your PWO whey (personally, I like a ~1.5:1 whey + micellar casein mixture) for EAAs, they don't come close... read more
Be that as it may - since the before and after values were taken with the same device the changes should be correct, so that both the slightly yet not statistically significantly ameliorated loss of lean body mass and, more importantly, the significantly higher degree of body fat loss in the EAA meal replacement (EAAMR) group speak in favor of the 5 servings of a the 170 kcal, 6g EAA per day. Moreover, "the sparing influence of muscle loss might have been demonstrated with a larger sample size", so that you can take it for granted that the preservation of precious muscle mass is an advantage of being choosy with your protein sources and preferring those with higher over those with lower essential amino acid contents.

On a related note: I don't know if you noticed, but with a total energy content of 850kcal and 30g EAA these 5 meal replacements did in fact have exactly those 10g+ of essential amino acids, I have repeatedly recommended to have with each of the 3 meals most people consume in the course of the day.

In all fairness, it should also be mentioned that despite not being significantly different at baseline, the body fat percentage of the subjects in the EAA meal replacement group was ~3% higher to begin with.This may seem irrelevant, since figure 2 compares lean mass and fat mass as absolute changes and not their percentages, but in the end, the amount of fat you you can drop within a given time-frame decreases with lower body fat percentages.

Do the energetic costs of protein synthesis drive fat loss?

Another interesting observation Coker et al. made is the close association between fat loss, on the one hand, and increased protein synthesis (55%), on the other hand. The researchers take this as an incentive to do one of the of the much loved calories in vs. calories out calculation and come up with the following hypothesis:
"Acute administration of EAAMR did promote a significant increase in skeletal muscle protein FSR compared to CMR. Assuming that the energy cost of protein synthesis is 3.6 kJ/g and the baseline GAIA-derived lean tissue mass was 56.4 kg for EAAMR and 54.4 kg for the CMR, we can extrapolate that the overall energy discrepancy between the two groups was roughly equivalent to 27,170 kcal or 3.5 kg of weight loss across the entire caloric restriction-based weight loss paradigm. Based on the amount of total lean mass in each group, this value takes into account a consistent intervention structure of five servings/day across an eight week period. In short, these calculations suggest that differences in the source of intact protein/formulation of EAA may have a significant influence on diet-induced energy expenditure that coincides closely with the greater reduction of adipose tissue in EAAMR compared to CMR." (my emphasis in Coker. 2012)
I usually discard fallacious calculations like this one if they are not highlight the stupidity of trying to eat exactly as much as some funky formula + the figure on your treadmill, pedometer, heart rate monitor or whatever fancy tool you may use to "measure" your energy expenditure suggest you would have burned in the last 24h. In this case, however, I made an exception, because I feel that the notion that protein quality is one of the myriad of parameters that are missing from this foolish calculation is important, for lean and obese people from all age groups who are trying to shed body fat.

Bottom line: The take away message of the study is in the end identical to the previously mentioned study by Loenneke et al.: Make sure you hit the 10g EAA threshold with each and every of your meals, if being lean and muscular not skinny yet fat is your goal.

References:
  • Coker RH, Miller S, Schutlzer S, Deutz N, Wolfe RR. Whey protein and essential amino acids promote the reduction of adipose tissue and increased muscle protein synthesis during caloric restriction-induced weight loss in elderly, obese individuals. Nutr J. 2012 Dec 11;11(1):105. [Epub ahead of print]
  • Jacobs EJ, Newton CC, Wang Y, Patel AV, McCullough ML, Campbell PT, Thun MJ, Gapstur SM. Waist circumference and all-cause mortality in a large US cohort. Arch Intern Med. 2010 Aug 9;170(15):1293-301.
  • Kastorini CM, Panagiotakos DB. The obesity paradox: methodological considerations based on epidemiological and clinical evidence--new insights. Maturitas. 2012 Jul;72(3):220-4.
  • Loenneke JP, Wilson JM, Manninen AH, Wray ME, Barnes JT, Pujol TJ. Quality protein intake is inversely related with abdominal fat. Nutr Metab (Lond). 2012 Jan 27;9(1):5.