Higher metabolic rate, not exercise, makes people naturally slim

Hopefully, this study will pour cold water on all the “fitness gurus” out there who preach (though, not often practice) the mantra “no pain, no gain”. Or in this case, instead of gain they mean loss – of fat mass, that is. If there is any industry that is recession-proof it is probably the exercise/fitness one, and its promoters have been engaging in increasingly bizarre advocacy, currently bordering on madness – i.e. eat as close to zero carbs as possible and move as much as possible. Despite this approach, the average BMI of “developed” countries continues to increase and now almost half of the Western population is overweight, while a quarter probably satisfies the criteria for (pre)diabetes. The study below demonstrates that when it comes to natural slimness it is all about the metabolic rate, and more specifically, all about the levels of active thyroid hormone (T3). In fact, it demonstrates that despite the much lower levels of physical activity the naturally slim people had great biomarkers of CVD, including cholesterol and blood pressure. That last finding is perhaps the most damning as it undermines the central argument for exercise – i.e. even if it does not  lower BMI it lowers those biomarkers and subsequent risk of CVD. In fact, considering that long-term exercise raises baseline cortisol, which further raises BMI and CVD risk, it looks like yet again the official recommendations in regards to health are about the exact opposite of what one should do. Instead of exercising ourselves to death while counting calories, we should be avoiding stress, avoiding anti-thyroid foods (PUFA anyone?) and (if needed) consuming pro-metabolic substances such as sugar, caffeine, aspirin, pregnenolone, progesterone, androgens…and, of course, thyroid.



“…To date most research on obesity has focused on studying those with a high body mass index (BMI), but a research group in China is taking a different approach. In a study published July 14 in the journal Cell Metabolism, the scientists looked at individuals with a very low BMI. Their findings reveal that these individuals are actually considerably less active than people with a BMI in the normal range, contrary to speculation that they have a metabolism that makes them naturally more active. Additionally, they eat less food than those with a normal BMI. “We expected to find that these people are really active and to have high activity metabolic rates matched by high food intakes,” says corresponding author John Speakman, a professor at the Shenzhen Institutes of Advanced Technology in China and the University of Aberdeen in the UK. “It turns out that something rather different is going on. They had lower food intakes and lower activity, as well as surprisingly higher-than-expected resting metabolic rates linked to elevated levels of their thyroid hormones.”

“…The investigators found that compared with a control group that had normal BMIs, the healthy underweight individuals consumed 12% less food. They were also considerably less active, by 23%. At the same time, these individuals had higher resting metabolic rates, including an elevated resting energy expenditure and elevated thyroid activity. “Although these very lean people had low levels of activity, their markers of heart health, including cholesterol and blood pressure, were very good,” says first author Sumei Hu, currently at the Beijing Technology and Business University. “This suggests that low body fat may trump physical activity when it comes to downstream consequences.”

Author: haidut