Saturday, April 28, 2012

Liposuction Shifts Fat from Subcutaneous to Visceral Fat Depots and Reduces Energy Expenditure by 5%!

Image 1: Without exercise and a healthy diet your fight against body fat is as desperate as Heracles fight against the Hydra without the help of his nephew Iolaus.
After yesterday's blogpost on the Biggest Losers, who - upon closer scrutiny - were not so bad of, as many people in the health and fitness community would have it, we will take a look at a more convenient and (accordingly *sigh*) increasingly popular way to get rid of the nasty lovehandles: Liposuction, or the costly reduction of subcutaneous body fat with a hopefully 100% sterile vacuum cleaner ;-) Aside from the risks that are directly related to the operation, a group of Brazilian researchers right from the mecca of plastic surgery, Sao Paulo, has just published a paper (2 days ago, to be precise) on another, hitherto totally overlooked side effect that arose subsequent to a small-volume tumescent abdominal liposuction (1240.3ml) in the sedentary half of 36 physically inactive (i.e. not engaged in any form of regular physical activity program for at least 6 months), yet non obese women (20 –35yr) who participated in the study (Benatti. 2012)

Remove it here, regrow it there. Body fat resembles the Hydra from Greek mythology

In order to control the outcome of the operation itself and its long(er) term consequences in the presence or absence of a physical exercise program that was conducted for four months starting 2 months after the OP (this yields a total duration of 6 months for the whole study), the Fabiana Benatti and her colleagues assessed the total body fat and fat-free mass of the participants via hydrostatic weighing and used computer tomographs to determine the size of the individual fat depots.
Figure 1: Changes in body composition relative to baseline (data calculated based on Benatti. 2012)
As you can see in figure 1 the comparatively reasonable exercise program the subjects in the training group (TR) performed three times per week during the last four months of the follow-up period and which consisted of a...
  • 5-min warm-up followed by 
  • strength exercises: 8 exercises for the major muscle groups, 3 sets of 12 reps, and
  • aerobic exercise on the treadmill: 30-40min at 75% of the VO2max
led to further reductions in subcutaneous fat mass. From a non-aesthetical perspective, it is yet more important that the three weekly exercise sessions prevented the vicious repartitioning effect from the subcutaneous to the visceral body stores, the cosmetic surgery had on the adipose tissue of the the women in the sedentary group (NT) in the course of the 4 months after their surgery.

Could it be that taking the easier way out is always a bad idea?

Image 2: Does look nasty, is not without risk and not effective in the long run - liposuction.
These results are interesting, because they do confirm the long-touted notion that plastic surgery would be pretty useless, if it is not combined with an adequate exercise and nutrition program. Moreover, the novel finding that the compensatory effects, i.e. the regrowth of body fat, does not take place in the subcutaneous fat depots, but in the vicinity of the organs, i.e. in the dreaded visceral adipose tissue stores, sheds an even more unfavorable light on a convenient, yet expensive, ineffective and - as this study shows - profoundly unhealthy attempt to "looking good naked".

The further reduction in subcutaneous fat and the absence of this highly unfavorable "repartitioning effect", on the other hand, speak to the effectiveness of a combined strength and endurance training program for female and, as we know from countless of other studies, also male weight loss - and that in the absence overtly restrictive eating.

Clear results with surprising effects on CVD risk and  energy expenditure

Still, there are a few downsides and shortcomings to this study that should not be overlooked. Firstly, the scientists did not evaluate the body fat distribution in the upper body, specifically the breasts. Whether there may have been a repartitioning effect from the abdominal to the upper body (e.g. breast, back and arms) subcutaneous fat depots, thusly remains to be elucidated. Moreover the increase in total LDL count, the scientists observed in the non-training group was not accompanied by increases in ApoB levels, which are considered as a relatively reliable marker for the number of the allegedly artery-clogging small LDL particles. Whether the women in the study are thusly actually facing an increased risk for cardiovascular disease or simply carry ~10% more visceral body fat around is about as questionable as the underlying cause of the reduction in energy expenditure that went hand in hand with the loss of ~1kg of subcutaneous body fat in the absence of a reduced caloric intake.
Figure 2: Significant (non-training, p = 0.01) and non-significant (training, p = 0.82) changes in doubly labeled water measured energy expenditure 6 months after liposuction (data adapted from Benatti. 2012)
In the end, the data in figure  2 relates directly to what we have seen in yesterday's analysis of the metabolic effects of a -60% reduction in body fat (cf. "Metabolic Consequences of Extreme Weight Loss"). If we assume that the 7-day food diaries provide an accurate estimate of the energy intake (if anything those logs usually underestimate / the participants underreport energy intake) and rely on the exactness of the relatively reliable doubly labeled water method you already know from yesterday's Biggest Loser study, the ~100kcal reduction in energy expenditure in the study at hand cannot be induced by restrictive eating (and in the non-training group obviously not by excessive exercise ;-), so that the Brazilian scientists conclude that...
our data suggest that the fat loss per se plays a role in decreased energy expenditure because no changes in food intake, lean mass, or leptin levels were observed.
And call for "[a]dditional studies" to "comprehensively explore the underlying mechanisms of the liposuction-induced decrease in energy expenditure". In view of the fact that these results could be of fundamental importance not only for the lazy plastic surgery patient, but also for the hard-training physical culturist who strives to push his / her body fat levels lower and lower, you can be certain that the SuppVersity is the place, where you are going to read about the results of future investigations into the underlying mechanisms first!