Increasing Adolescent Obesity Among Girls: How School Stress is the New Scapegoat When the Skinny Fat Phenomenon and Twinkie Diets Really are to Blame.

Image 1: Was it school stress that cost Michelle Obama her famous "guns" (=muscular upper arms)? Probably not - and despite contrary conclusions in the study at hand, I doubt that it is school stress that leaves our daughters fat, but undermuscled. What do you say?

According to the results of a recent evaluation of the data from the European HELENA trial, school, or rather the stress your children are exposed to within the educational system, may be one of the reasons for the increasing number of obese adolescents (age 12-18 years) - at least if we trust the statistical finesse of Tineke De Vriendt, Els Clays and 10 other scientists who recently published a paper on European adolescents’ level of perceived stress and its relationship with body adiposity in the European Journal of Public Health (DeVriendt. 2011). The study was part of the Healthy Lifestyle in Europe by Nutrition in Adolescence cross-sectional study (HELENA-CSS), the aim of which is to obtain "reliable and comparable data from a selected cohort of European adolescents concerning a broad variety of parameters related to nutrition, health, physical activity and fitness", or in other words, to provide the epidemiological back-bone for the formulation of more or less mainstream hypotheses on "why we are getting sick and obese"... be that as it may, with a sample size that allows for a confidence level of 95% and <0.3 error and 3865 adolescents from more than 10 European cities, the data from the HELENA study is probably the best we can get at the moment and thus you may nonetheless be interested to hear that ...

School-related stress was demonstrated to be a main source of stress in European adolescents, [...and] in adolescent girls (but not in boys), a positive association was observed between their level of perceived stress and measures of general and abdominal obesity.

If you have a closer look at the stress data, expressed on a 6-scale Likert scale from 1 = ‘Not at all stressful’ over  2 = ‘A little stressful’, 3 = ‘Moderately stressful’, 4 = ‘Quite stressful’ to 5 = ‘Very
stressful’ (with 6 indicating ‘Is irrelevant to me’), you will notice that school and the closely related fear of an "uncertain future" are in fact the major stressors in the life of our adolescent children (and you may safely assume that the results won't be very different in the US).

Figure 1: Overview of perceived stressors; values expressed on a Likert-scale from 1 to 5 (data adapted from DeVriendt. 2011)

In that, it is yet interesting to observe that none of the stressors is on average perceived as "quite stressful" or even "very stressful". It is also noteworthy that on 5 out of 10 scales and on the summary scores girls experienced more stress than boys. In view of the scientists previously cited conclusion (of which I do not have to tell you that it is based on one of those sophisticated *cough* statistical models) that only "in adolescent girls (but not in boys), a positive association was observed between their level of perceived stress and measures of general and abdominal obesity", it may thus surprise you to hear that the obesity rate among boys is more than 2x higher than among adolescent girls (cf. figure 2). So how is that?

Figure 2: Body adiposity characteristic of study sample (n=1121) of adolescents from the HELENA trial (data adapted from DeVriendt. 2011)

Well, we all know that even with a perfectly "normal" BMI, you can easily be "skinny fat". A phenomenon of which I feel that it is becoming the norm, not the exception, among adolescent girls, who - after their nth an-apple-a-day diets have lost nothing but muscle and thus have a very high body-fat percentage with a low overall body-weight.

This hypothesis would be confirmed by the regression coefficients of the statistical models from the study, according to which the association of perceived stress with the body fat level of the girls is 7x higher than the association of perceived stress and BMI, which is something that should you make reconsider, whether

1. body weight and BMI is an important biological measure, at all,
2. the real "obesity" rate, including skinny fats, among girls is not way higher than the 1.9% reported in the study would suggest, and
3. in how far school-stress, despite being the "major stressor" in this survey and not a misguided beauty-ideal is to blame for the increasingly unbalanced ratio of lean to fat mass in adolescent girls

The importance of the latter, i.e. a questionably beauty-ideal, in the etiology of (and this would be ironic if it was not so unfortunate) diet-induced obesity could also explain that the pubertal stage the girls were in and not stress or their diet had the greatest "explanatory value" (remember: we are talking of associations here) in regard of their body fat levels (cf. figure 3).

Image 2: Low self-esteem and false beauty-ideals pave the way into disordered eating and life-long misery. Something you want to spare your daughter and son, don't you?

Did you know that according to a 2000 national survey 45% of the girls, but only 20% of the boys from 5th to 12th grade reported to have tried one or more diets at some point in the past (Neumark-Sztainer)? And would you have guessed that 17% did even consider their own eating behavior as already "distorted"? Needless to say that both of these factors showed a high correlation with overweight status, low self-esteem, depression, suicidal ideation, and substance use; and certainly reason enough for you to help our children (girls and boys) not to fall victim to ill-advised beauty-ideals and false dietary recommendations.

And from the fact that the same variable had 7x less predictive value in boys, who obviously do not want to be skinny fat and refrain from Twinkie-style low calorie, low fat dieting, we can with some caution (due to hormonal effects on fat accumulation) conclude that it is not just a time factor, meaning that the older girls have more time to accumulate body fat...

Figure 3: Regression coefficients (=associative strength*100) of stress or pubertal stage with body-fat percentage in adolescent boys and girls from the HELENA trial - mind the logarithmic scaling! (data adapted from DeVriendt. 2011)

Now, what can you do about that? Well, without even knowing you probably have already done something! Assuming that you (just like every other reader of the SuppVersity ;-) are of above-average intelligence, your education has already provided your daughter, but not your son, with a better chance of staying lean than her peers from less educated parents (~80x higher explanatory value than stress!). All that is left now to make absolutely fat-proof, is to tell her that strong, not skinny fat is the new beautiful ;-)

Lack of Cortisol characteristic for young obesity patients. Plus: Self-Esteem Changes During Puberty Would Actually Increase Diurnal Cortisol Production

Cortisol is not your enemy. In fact, cortisol is one of the few hormones you really need to survive.

Cortisol is a problem. However, just as it is the case with insulin, it's not the fact that your body produces it that's problematic. It's the fact that it tends to so in copious amounts and chronically, simply at the wrong time or - believe it or not - not at all / enough. All that, i.e. changes / problems with the natural rhythm, the up and down, the spikes and troughs that get lost, when you are chronically stressed and/or inflamed - that's the actual problem and not the fact that your body produces a hormone without which you can't survive.

You can learn more about cortisol at the SuppVersity

Kaatsu, cortisol, gains?

Roibos for relaxation

Leucine + cortisol = bad news

BB = max cortisol = max fat loss?

7-keto save and effective?

Cortisol reducing bites

Against that background, it may go against everything the supplement industry is trying to tell you, but still cannot be really surprising to hear that E. Allansson Kjölhede and colleagues from the Linköping and Ume a Universities present in their latest paper in Acta Pædiatrica results that show that obese children have low, not high cortisol levels (Kjölhede. 2014).

Using three salivary samples from 342 children aged 6–12 years the scientists had tried to reconcile previous, inconsistent findings and found that the

"average cortisol levels in early morning, late morning and evening were significantly lower in overweight and obese children than in their normal weight counterparts."

What's particularly interesting is that the early morning spike, we have identified as critical component of a healthy biorhythm, previously (see "All About Cortisol"), was reduced by -33% (see Figure 1):

Figure 1: Morning (8:30 am), late morning (10:30 am) and evening (9:00pm or pre-bed, if earlier) salivary cortisol in 342 normal-weight, overweight and obese children (Kjölhede. 2014).

As Kjölheide et al. point out, these results should be followed up by more comprehensive studies that would allow us to better classify and understand the "relationship between stress and obesity in
children" - and I would like to add: Which of these comes first - being obese or having low morning cortisol and thus not being able to benefit from the "wake-up and get going" effects of cortisol.

This is not a statistical outlier: The results of the study at hand are not a statistically irrelevant outlier or something that would be observed in children, only. In 2013 Champaneri et al. a corresponding correlation between high early morning cortisol levels and lower body fatness and waist circumference, when they analyzed data from the 1,002 subjects of the Multiethnic Study of Atherosclerosis (Champaneri. 2013)

That's also interesting, because previous studies by Toledo-Corral et al. have shown that a dampened cortisol awakening response is not just associated with obesity, it is also a predictive factor of higher carotid artery intima-media thickness (CIMT) in overweight African American and Latino youth (Toledo-Corral. 2013), which in turn is a risk factor for myocardial infarction and stroke.

And Ursache et al. (just because it's funny: "Ursache" means "cause" in German ;-) report that  dolescents with insulin resistance exhibited

• a blunted cortisol awakening response (CAR),
• smaller hippocampal volumes, and 
• greater frontal lobe atrophy 

compared to controls. Closer scrutiny of the data also revealed that "a smaller CAR was associated with higher BMI which was in turn associated with fasting insulin levels" (Ursache. 2012).

Despite the fact that it is virtually impossible to tell what exactly the "ursache" for the irrefutable correlation between low morning cortisol levels and high body fatness, artery intima-media thickness, myocardial infarction and stroke is, the cumulative evidence clearly speaks against the use of cortisol-reducing drugs and supplements - at least if their effects are not extremely short-lived and will thus not mess with the natural up-and-down that's lost not just in obese, but also in chronically fatigued patients.

Bottom line: In view of the data presented above, people with low morning cortisol levels would thus be better advised to start their day with some "delicious" licorice - or better a capped extract - to benefit from its cortisol boosting effects, instead of "cortisol blockers".

Figure 2: Comparison of reduction in % body fat in response w/ licorice (blue, Tominaga. 2009) and no dietary restriction vs. 7-keto + dietary restriction (red, Zenk. 2002 - sponsored study).

Bullshit? Well, what about the side-effect free (no change in Hb1AC, improved not worsened blood pressure and pulse rate and in range serum electrolytes) reversal of fat gain Tominaga et al. observed in obese subjects who consumed a polyphenol-laden licorice extract (main ingredient glabradin) at dosages of 300mg and 1800mg per day for 12 weeks (Tominaga. 2006), then?

Or the significant decrease in body fat the same researchers observed in another study, three years later with 300, 600 and 800mg/day of a licorice flavonoid oil (see Figure 2)? Significantly more than in allegedly only 8 weeks on 7-keto, by the way; and that a despite the fact that the sponsored study on the DHEA-metabolize by Zheng et al. (2002) used a combined diet + supplementation protocol (see Figure 2).

Reference: 

• Champaneri, Shivam, et al. "Diurnal salivary cortisol is associated with body mass index and waist circumference: the Multiethnic Study of Atherosclerosis." Obesity 21.1 (2013): E56-E63.
• Toledo-Corral, Claudia M., et al. "Blunted nocturnal cortisol rise is associated with higher carotid artery intima-media thickness (CIMT) in overweight African American and Latino youth." Psychoneuroendocrinology 38.9 (2013): 1658-1667.
• Tominaga, Yuji, et al. "Licorice Flavonoid Oil Effects Body Weight Loss by Reduction of Body Fat Mass in Overweight." Journal of health science 52.6 (2006): 672-683.
• Tominaga, Yuji, et al. "Licorice flavonoid oil reduces total body fat and visceral fat in overweight subjects: A randomized, double-blind, placebo-controlled study." Obesity research & clinical practice 3.3 (2009): 169-178.
• Ursache, Alexandra, et al. "Preliminary evidence for obesity and elevations in fasting insulin mediating associations between cortisol awakening response and hippocampal volumes and frontal atrophy." Psychoneuroendocrinology 37.8 (2012): 1270-1276.
• Zenk, John L., et al. "The effect of 7-Keto Naturalean™ on weight loss: A randomized, double-blind, placebo-controlled trial." Current therapeutic research 63.4 (2002): 263-272.