SPORTS PERFORMANCE
PHOTO CREDIT: iSTOCK: STEFAN 032
‘ When Chewie loses his marble’ s!’
A recent study by Polidori, Sanghvi, Seeley, & Hall( 2016) helped explain this. They assessed a 52-week randomised double-blind, placebo controlled trial. This involved 153 type-two diabetic subjects treated with a drug that increases urinary glucose excretion that has subjects expending energy without even being aware of it. The drug treated subjects lost 3.5kg of weight over the course of the study, but with their weight coming to a halt at eight months, despite the constant infusion of the drug for the rest of the 12 months. Sound familiar? Using a mathematical model to quantify energy intake, the results demonstrated that as weight loss ensued, active control of energy intake exponentially increased by around 350 Calories per day, which by eight months prevented further weight loss( Polidori, Sanghvi, Seeley, & Hall, 2016). In fact, active control of energy intake was three-times larger than the corresponding energy expenditure to weight loss. This means that for every kilogram of weight lost, the subjects increased their energy needs by 100 Kcal’ s per day in an attempt to regain weight!
So, what’ s going on here?
Well, both impulses are working overtime, in a bid to restore lost body fat. As weight loss ensues, a biological persistence to drive up appetite, which appears to increase three times greater than the reduction in weight induced metabolism, persist in a bid to restore previous weight levels. This sets up an easy environment for weight gain. Even consuming calories to maintain weight is highlighted by the researchers as demanding exceptional will power and restraint simply to avoid overeating beyond maintenance needs. A lot of this, we can attribute to low circulating leptin levels. For instance, put someone who’ s lost 10 per cent of their weight under a brain scan and measure responses to seeing food vs non-food items in a glass box. Brain areas related to homeostatic, emotional and cognitive responses will light up like a Pin-ball machine in the 10 per cent weight loss subjects compared to those who lost the same amount of weight, but have been provided with twice daily leptin injections( Rosenbaum, Sy, Pavlovich, Leibel, & Hirsch, 2008). With all of this information in mind, losing weight comes with changes in‘ defence hormones’ that react with the mission of restoring previous fat stores.
134 MUSCLE & FITNESS / MARCH 2018