Диетологи нашли самый стройный из народо

[Terek]

Чеченцы самые стройные

This article, it is from 2007, says that the most slender ethnicity of the Russian Federation are the Chechens. It explains that they have the healthiest way of life, with food in moderation, athletics, and a clean environment. Only 10% of the population is overweight. In other regions in Russia it is 40%.

Ну, и говорят, что дело в войне, но я с тем не согласна, я считаю, что у нас просто генетически тип такой, хотя у отца моего не совсем... и тоже дело в культуре, у нас не принято стать слабым или толстым))) особенно у молодых)))

Чеченцы сильнее и красивее всех!

[Humanophage]

Baltids tend to be corpulent. In addition to the reasons stated in the OP (fighting sports, healthy diet, etc.), I'd like to point out two more:
1) Low median age. The median age for Chechens is vastly lower than for many other nations in Russia due to very high birth rates. E.g., 37 years for Russians vs. 22 years for Chechens; ~15% Chechens are older than 50 vs. 35% Russians. The implications for metabolism are obvious.
2) Low urbanisation. The Chechen Republic has one of the lowest urbanisation rates in Russia. While socially not a benign sign, it obviously leads to a better diet and more physical activity.

One thing I would be extremely interested in is average IQ for various regions of Russia, with large samples and no cheating. It's like a little dream of mine.