Tuesday, April 30, 2013

Switch From Chicken to Lamb to Rid Yourself of Belly Fat, Reduce Your Triglyceride and Basal Insulin Levels

If you consider this, i.e. you suprailaic body fat (here measured by a caliper, just as it was done in the study at hand), ditching the chicken for some lamb, may be one of the myriad factors that could help you "solve" the problem.
Chicken, rice and broccoli. That is still the dietary paradigm, most people have on their minds, when average Joes and Janes are talking (often with some disdain) about what "healthy eating must look like".

Now, a recent study from GENUD, the "Growth, Exercise, Nutrition and Development" Research Group at the Universidad de Zaragoza in Spain (Graffe. 2013) suggests that at least item #1 on that list, namely chicken, would have been better replaced with a protein source of which I suspect even most of you won't be consuming on a regular base: Lamb!

That a proper sleep hygiene is of utmost important for your health and body composition is something you, as a SuppVersity veteran will be highly familiar with (if you are a newbie read yourself smart, here).

"Switch out the light and dish up the lamb, bro!"

That the second part of the jovial imperative in the above headline could be another factor to take into consideration, on the other hand, is true news (even for me) and should - with only one study backing it up - be considered more of an empirically grounded hypothesis than a "100% certain scientific result".

Table 1: Cooking methods for both lamb and chicken (Graffe. 2013)
Nevertheless, the observations, MarĂ­a Isabel Mesana Graffe and her colleagues made, when they put a group of healthy 16-26-year old "men" and "women" (I know, when I was sixteen, I thought I was a man, too - little did I know ;-) from Teruel and Zaragoza on an 8-week dietary regimen containing either...
  • 150 grams of chicken, three times per week, or
  • 150 grams of boneless lamb, three times per week,
... are quite intriguing. The participants received their otherwise (roughly) identical diets in in their local university accomodation halls:
"To ensure harmonisation, product-rich diets were served during lunch time and with each chef of the designated university accommodation halls were given instructions on the cooking methods." (Graffe. 2013; cooking methods, see table on the right)
The whole study design was in fact pretty straight forward and resembles an ideal world, where the citizens obey to dietary recommendations like "eat at least three meals with 150g of lamb per week" as if their lives depended on it (is it ironic or just sad that it actually does depend on the pathetic advice people are given?).

After an initial visit at which the medical history of all participants was assessed, a first blood draw, as well as anthropometric, blood pressure and heart rate measures were undertaken. After an 8-week period, all subjects came in for a second visit and the second testing session and crossed over to the other other group, i.e. subjects who had been consuming chicken for the first 8-weeks were then assigned to eat lamb and vice versa.

2x 8 weeks + an intermediate 5-week washout later...

Thus, after 8 weeks on diet A, a 5-week washout and another 8-weeks on diet B, all subjects had been consuming one or the other diet for 8 weeks, when they eventually arrived for the third and last assessment of their cardiovascular risk markers, body composition, blood pressure and heart rate.
Figure 1: Changes in skinfold thickness (before vs. after) and corresponding arm, hip and waist circumferences in the participants after 8 weeks on the "chicken" vs. "lamb diets" (Graffe. 2013)
As I know that "looking good naked" is much sexier (in the literal, as well as the figurative sense), than being healthy, we'll take a look at the anthropometric data, first (see figure 1). It probably doesn't take much explaining on my side. The general trends speak for themselves and I guess, you won't complain that it is in the change of the amount of fat that's covering the abs, where the scientists observed the only significant inter-group differences - do you?
Figure 2: Changes in blood lipids cardiovascular parameters, glucose and insulin levels during the 8-week chicken / lamb diet phases; only non-pastel bars are statistically significant  (Graffe. 2013)
With the fat mass differences being most significant in the abdominal area, it is also no surprise that the major changes among the cardiovascular risk parameters were (a) reduced triglyceride levels and (b) improved insulin levels - exactly those parameters that are usually most closely related to abdominal obesity and "all things metabolic syndrome".

Not chicken or lamb, "chicken or egg" - that's the question!

These observation do obviously rise the usual SuppVersity question: "What's the mechanism, here?" What is certain is that the beneficial effects on abdominal fat, trigs and insulin are not due to the clenbuterol residues in chicken (up to 224ng/g; cf.Malucelli. 1994) cyclists love to use as an excuse, when they have once again been busted for the abuse of beta-agonists. Why? Well than eating chicken should help not hinder leaning out. Could it be the remnants of antibiotics in the chicken meat, as proposed by eg. Nicholson et al. (2005)? Or is it simply the bad arachidonic acid chicken common wisdom will tell you that it was so high in chicken meat?
Figure 3: Fatty acid composition of beef, lamb, pork, chicken, duck and turkey in % of total lipids (left) and arachidonic acid content in mg/100g (Li. 1998)
If you peek at the data in figure 3, which is obviously not based on the dietary intake of the subjects in the study at hand, but displays the general fatty acid composition of various meats, including lamb and chicken (both marked with grey boxes) as they were reported by Li et al. in 1998, it would appear as if "everybody's favorite devil", the essential omega-6 fatty acid arachidonic acid can hardly be blamed for the superiority of lamb - after all there is about the same amount of it in lamb as there is in chicken (for Ducks and dark poultry things are different!)

Did you know that lamb is the #1 dietary source of CLA?

Lamb contains 5.6 mg/g CLA, whereas beef and veal contain only 2.9–4.3 mg/g and 2.7 mg/g, respectively.

Non-ruminant meats such as chicken and pork, contain 0.9 mg/g and 0.6 mg/g, respectively (Mulvihill. 2001).

Eggs contain no CLA, at all - unless the chicken are fed with CLA enriched diets and the yolk between 3mg and 14-32mg/100g total fat (Jones. 2000; Raes. 2002).

Whether the CLA is at the heart of the effects in the study at hand is yet questionable, after all one of the side effects is insulin resistance and that's the opposite of what the sign. decrease in insulin would suggest.
What could be a culprit, though is the overall higher n-6/n-3 ratio of chicken. There is no debating that there is a statistically significant difference between chicken with 9.73g of omega-6 fatty acids per omega-3 vs. lamb in which every omega-6 fatty acid is "appropriately (?) buffered" with 0.57g of omega-3s (the corresponding n3/n6 ratios are 1.59, 1.78, 13.92, 9.73, 10.82 and 10.53 for beef, lamb, pork, chicken, duck and turkey, respectively; data based on Li. 1998).

But is it really that easy? The n3/n6 ratio - again!? I 'd say no. Also, or rather particularly in view of the relatively lose dietary control... I mean, if you have to eat chicken at least three times a week in the canteen, you are certainly more likely to grab a burger with "red meat" (or whatever it is they put in-between the patties) on the weekends or in the evening.

This and other confounding factors would obviously negate neither the previously mentioned n3/n6 ratio hypothesis, nor the scientists' very own hypothetical explanation that the "the presence of unsaturated fats [...], such as oleic acid and conjugated linoleic acid" which are naturally high in ruminant meat (see infobox on the right), can have figured here, as well. It should however remind you that there is, if anything, only one single reason that "we are fat" and that's the way "experts" base their advice on observations like these, cherry pick those they like and discard the ones they don't like until the various net result - call it the "XY diet" or the "dietary guidelines" - confuse the hell out of the poor average Janes and Joes who are looking up to those "experts" to rescue them before the obesity pandemic carries them off just like the 35.7% of the US adults who are already obese (the latest data is still based on figures from 2009-10; cf. Ogden. 2012)

If you work anyway similar to a male rodent, 4g/day Tongkat Ali, could help with the abs, your testosterone levels and "other issues", as well (learn more)
Bottom line: My personal take away message from the study at hand is not "never eat chicken again" or "eat lamb everyday", but rather: "Don't forget about how lucky we are that we have so many foods to chose from." So don't get stuck on only one of them - and that regardless of what common wisdom, recognized or unrecognized experts or individual studies may suggest would be "best" for the way you look and feel!

There is no magic bullet and no singular reason that "we" are fat and I am 100% sure that eating chicken instead of lamb is the smallest obstacle standing between your and a shredded set of abs.

    • Jones S, Ma DW, Robinson FE, Field CJ, Clandinin MT. Isomers of conjugated linoleic acid (CLA) are incorporated into egg yolk lipids by CLA-fed laying hens. J Nutr. 2000 Aug;130(8):2002-5.
    • Li D, Ng A, Mann NJ, Sinclair AJ. Contribution of meat fat to dietary arachidonic acid. Lipids. 1998 Apr;33(4):437-40.
    • Malucelli A, Ellendorff F, Meyer HH. Tissue distribution and residues of clenbuterol, salbutamol, and terbutaline in tissues of treated broiler chickens. J Anim Sci. 1994 Jun;72(6):1555-60.
    • Mulvihill, B. Ruminant meat as a source of conjugated linoleic acid (CLA). Nutrition Bulletin. 2001; 26: 295–299. 
    • Ogden CL et al. Prevalence of Obesity in the United States, 2009–2010. NCHS Data Brief No. 82 January 2012.
    • Nicholson JK, Holmes E, Wilson ID. Gut microorganisms, mammalian metabolism and personalized health care. Nat Rev Microbiol. 2005; 3:431–438.
    • Raes K, Huyghebaert G, De Smet S, Nollet L, Arnouts S, Demeyer D. The deposition of conjugated linoleic acids in eggs of laying hens fed diets varying in fat level and fatty acid profile. J Nutr. 2002 Feb;132(2):182-9.