Dukan Diet

High intensity thinking - intelligent weight loss workouts

Its almost 2014! Actually it is already 2014; at least for my friends in the "Far East" (HAPPY NEW YEAR!) and thus almost too late for the annual "I want to lose weight" new years resolution. Ok, you as a SuppVersity reader should actually know better, but just in case you are still planning to make the weight loss happen solely by increasing your workout volume, I would suggest that you replace some classic HIT training with the revolutionary HIT 2.0 - high intensity thinking regimen (warning: doing this too often may actually build more brain than muscle mass ;-). 

Well,... now that I take a closer look at the results of this recent study from the University of Quebec here,  I have to realize that this will only work if you are a man. But dont worry, I am pretty sure there is something to be learned for the ladies in the last SuppVersity article of 2014, as well ;-)

All jokes aside, your brain is a sucker for energy!

I guess you will be familiar with the over-cited fact that "the human brain is only 2% of the weight of the body, but it consumes about 20% of the total energy we need every day"... I know thats boring, but actually thats quite an important point, because it tells you that your brain is not just a sucker for energy, but also a sucker for new information, which will in turn increase the energy requirements of the insatiable heap of neurons in your skull. Why? Well, our brains need energy to process each and every of these information chunks - max. 30W per opeartion, if the currently heralded estimations are correct. I know that sounds tremendously much, but if we performed only one of these operations per minute, you would hardly burn the energy equivalent of 1/25 of a 70-85% chocolate bar during your high intensity thinking sessions.

Against that background its all the more impressive that Emilie Pérusse-Lachance and her Canadian colleagues were able to measure a significant increase in energy expenditure, when they had their 35 subjects (22 men and 13 women; aged 24 ± 3 years) read a 10-page text and write a summary of approximately 350 words using a computer in the "mental work condition" of their study.

Figure 1: Energy expenditure in kcal/45min in the control and the mental work condition, left; energy intake during the buffet ca. 15min after the control and mental work condition, right (Pérusse-Lachance. 2013)

If you take a look at the data in Figure 1, you will also notice that the scientists original hypothesis, which was that they would observe a similar hyperphagic (=hunger ➲ increased energy intake) response to in the "mental work" condition as Chaput et al. who conducted two very similar studies in 2007 and 2008.  The actual study outcome does yet tell a different story: While the female study participant did in fact supercompensate for the extra-energy they had to spent, when they were not watching TV and lolling around like in the control condition, the men were probably so immersed in their thoughts that they simply forgot to eat... ok, I guess you already realized that this was an ad-hoc hypothesis to make sure you dont realize that neither I nor the scientists have any clue what the underlying reasons of this sex-difference were.

I would even guess that the women did not even notice that they were overcompensating. If you take a look at the subjective hunger scores that have been assessed by seven visual analogue scale questionnaires the participants had to fill...

1. at the beginning (T-60/60 minutes before the buffet), 
2. after the experimental session (T-15/15 minutes before the buffet), and 
3. after the buffet-type meal (T0, T60, T120, T180, and T240).

...those will tell you that the ladies either claimed to, or actually werent more hungry than in the control condition. In view of the irrefutable evidence that they still ate more (see Figure 1) this may look awkward. When its all said and done, these contradictory result does yet only confirm that you cannot trust people, when they tell you "I am never hungry and actually dont eat that much.... I have really NO clue where that belly comes from". This may even be their own perception, but that does not change that it is usually not in line what happens at the buffets, dinner tables and - most importantly - during the snack breaks people take during not after their high intensity thinking regimen all over the world.
References:

• Chaput, J. P., & Tremblay, A. (2007). Acute effects of knowledge-based work on feeding behavior and energy intake. Physiology & behavior, 90(1), 66-72.
• Chaput, J. P., Drapeau, V., Poirier, P., Teasdale, N., & Tremblay, A. (2008). Glycemic instability and spontaneous energy intake: association with knowledge-based work. Psychosomatic medicine, 70(7), 797-804.
• Pérusse-Lachance, E., Brassard, P., Chaput, J. P., Drapeau, V., Teasdale, N., Sénécal, C., & Tremblay, A. (2013). Sex Differences in the Effects of Mental Work and Moderate-Intensity Physical Activity on Energy Intake in Young Adults. ISRN Nutrition, 2013.